Cold water immersion (a.k.a., “ice baths”) has become a popular method amongst exercise enthusiasts and athletes to enhance recovery after an intense training bout. The strategy involves exposing either the trained limb or the whole body to very cold liquid temperatures. According to p...
Brad Schoenfeld, Ph.D, C.S.C.S., is an internationally renowned fitness expert and widely regarded as one of the leading authorities on body composition training (muscle development and fat loss). He is a lifetime drug-free bodybuilder, and has won numerous natural bodybuilding titles.
If you follow my work you’ll undoubtedly know that our lab has carried out a number of studies seeking to determine the effects of training in different repetition ranges on muscle strength and growth. The overall findings from these studies showed similar increases in hypertrophy between both heavy and moderate rep ranges, as well as moderate and high rep ranges.
However, the choice of rep ranges is not necessarily an either-or proposition; you can in fact combine strategies to potentially achieve greater hypertrophic benefits. Daily undulating periodization (DUP) routines are specifically designed for this purpose. However, no study to date had compared a varied rep approach to traditional constant-rep training using site-specific measures of muscle growth.
Until now.
Our study, just published in the International Journal of Sports Medicine, set out to investigate if muscular adaptations would differ between DUP-style routine and a traditional hypertrophy-style protocol. Here’s the scoop.
What We Did
Nineteen young men with over four years average resistance-training experience were randomly assigned to 1 of 2 experimental groups that trained 3 days per week: a constant-rep protocol (CONSTANT) that trained using a standard bodybuilding rep range of 8-12 RM per set, or a DUP-style varied-rep protocol (VARIED) that trained with 2-4 RM per set on Day 1, 8-12 RM per set on Day 2, and 20-30 RM on Day 3. All subjects performed a total-body routine consisting of the following seven exercises per session: flat barbell press, barbell military press, wide grip lat pulldown, seated cable row, barbell back squat, machine leg press, and machine knee extension. We tested subjects for changes in hypertrophy of the arm flexors, elbow flexors and quads, as well as maximal strength in the squat and bench press, and upper body muscle endurance. Training was carried out over an 8-week period, with testing done pre- and post-study.
What We Found
Both groups significantly increased markers of muscle strength, muscle thickness, and local muscular endurance. No statistically significant differences were found between conditions in any of the outcomes studied. Sounds like it really doesn’t matter which option you choose, right?
Well, not so fast…
It’s important to understand that the term “statistically significant” simply refers to the probability of results being due to chance at a predetermined level of 5%. This binary method of determining probability has been widely criticized by those in the know about statistics, who proclaim that practical conclusions cannot be drawn merely on the basis of whether a p-value passes a specific threshold. Rather, probability exists on a continuum, and in this regard the p-values (a measure of probability) in our study favored the VARIED condition in several outcome measures. Moreover, magnitude-based statistics (i.e. effect sizes) indicated a benefit to the VARIED condition for upper body hypertrophy, strength, and muscular endurance; no effect size differences were noted for lower body outcomes.
What are the Practical Implications
The study showed a potential benefit – albeit small – to varying repetitions across a spectrum of ranges for increasing upper body muscle strength and hypertrophy. Whether the differences between the varied versus constant rep approach seen in our study would amount to practically meaningful improvements is specific to the individual. For the average gym-goer it probably wouldn’t be of much consequence; alternatively, to a bodybuilder or competitive athlete it very well may. It’s not clear why these findings did not translate into similar differences in lower body muscular adaptions, but based on our findings either approach would seem to be an equally viable choice for leg training.
It’s important to note that this was a relatively short-term study, lasting a total of 8 weeks. When factoring in missed sessions, this means subjects in VARIED trained in each loading zone for a total of only 7-8 sessions over the course of the study period. If the differences in upper body outcomes favoring VARIED would persist over time – highly speculative but certainly possible – the magnitude of results could widen and thus be potentially meaningful for a wide array of fitness enthusiasts.
Another important point is that volume load was consistently lower across all conditions (pushing exercises, pulling exercises, leg exercises, and total volume of all exercises) in VARIED as compared to CONSTANT. This indicates that training in a varied fashion provides comparable or better results with less volume load than training at a constant 8-12 RM repetition range. It also suggests that if volume load were equated between conditions, there might have been even better results for the varied approach.
In sum, our study shows that both varied and constant loading schemes are viable strategies to increase strength and hypertrophy in resistance-trained men. The data suggest a potential modest benefit to varying loading ranges over time, at least for maximizing upper body muscular adaptations. Importantly, findings clearly indicate that contrary to what many believe, training in the “hypertrophy zone” (6-12 RM) is not superior for building muscle. When considering the practical implications of the findings, remember that exercise prescription is always a function of the needs/abilities/goals of the individual.
Current resistance training guidelines recommend long rest intervals (i.e. 3 minutes) to maximize muscle strength. Alternatively, short rest intervals of around 1 minute are generally recommended for maximizing muscle growth. This is based on the premise that higher metabolic stress associated with limiting rest between sets will promote a greater muscle-building stimulus. Some have specifically pointed to acute post-exercise increases in anabolic hormones as a primary driving factor in the process.
Back in 2014, I co-authored a review paper on the topic with my colleague Menno Henselmans that was published in the journal Sports Medicine. After a thorough scrutiny of the literature, we determined that there was little basis for the claim that shorter rest intervals was beneficial to hypertrophy. As I discussed in this blog post, It would appear from current evidence that you can self-select a rest period that allows you to exert the needed effort into your next set without compromising muscular gains. That said, our recommendations were limited by a dearth of controlled studies on the topic. Moreover, no study had investigated the generally accepted guidelines of taking 3 minutes rest for strength gains and 1 minute for hypertrophy in resistance-trained individuals.
Until now…
I recently collaborated on a just-published study that investigated the effect of rest intervals on strength and hypertrophy. Here’s the scoop:
What We Did
A cohort of 21 young men were randomly assigned to either a group that performed a lifting routine with 1- or 3-minute rest intervals. All other resistance training variables were held constant. Subjects performed a typical bodybuilding-style routine that comprised 7 different exercises working the major muscle groups of both upper and lower body. Three sets of 8-12RM were performed per exercise. Training was carried out 3 days a week for 8 weeks.
We tested subjects immediately before and after the study period. Tests for muscle strength included 1RM for the bench press and back squat. Muscle-specific growth was assessed by b-mode ultrasound for the elbow flexors, triceps brachii, and quadriceps femoris.
What We Found
Maximal strength was significantly greater for both 1RM squat and bench press for the group taking longer rest. No big surprise here. Somewhat unexpectedly, however, muscle thickness tended to be greater when taking longer rest intervals as well. Although we can’t be sure of the underlying mechanisms, we speculated that results may be attributed a reduction in total volume load (i.e. reps /x/ load) over the course of the study. There is a well-established dose-response relationship between volume and hypertrophy, whereby higher volumes correlate with greater muscle growth. Thus, very short rest periods may compromise growth by reducing the amount of weight you can use on subsequent sets. This would indicate that if there are synergistic benefits to heightened metabolic stress, they are overshadowed by the associated decreased volume.
What are the Practical Implications
The obvious take-home here would seem to be that resting 1 minute between sets compromises gains in muscle size. But if 1 minute is in fact too short a rest period, how long should you then rest when maximal hypertrophy is the goal? Well, based on previous work in well-trained individuals, it would seem that 2 minutes provides sufficient recovery so as not to undermine growth.
That said, it’s important to take these results in proper context. Realize that we looked only at effects of the two respective conditions (i.e. 1- versus 3-minutes rest) on muscular adaptations. But rest interval length does not have to be a binary either-or choice. There is no reason you can’t combine different rest periods to potentially maximize hypertrophy.
A viable strategy is to take longer rest intervals on your large-muscle compound exercises such as squats, presses and rows. These movements generate very high levels of metabolic disturbance, particularly when performed with moderate rep ranges (i.e. 8-15 reps). Thus, longer recovery periods are needed to fully regenerate energy levels for your next set so that volume load is maintained across sessions.
On the other hand, single joint movements are not as metabolically taxing and thus you’re able to recover more quickly from set to set. Exercises like biceps curls, triceps pressdowns, and leg extensions therefore could conceivably benefit from shorter rest periods. In this way, you can heighten metabolic stress and its potential hypertrophic benefits without negatively impacting volume load. In this scenario, it’s best to keep the short-rest sets at the end of your workout to ensure they don’t interfere with recovery of compound exercise performance.
A final word: Research is still emerging on this topic. Each study is simply a piece in a puzzle. As more studies are carried out we’ll hopefully develop a better understanding of how programming can be tweaked to maximize the growth-related response. Stay tuned.
Split routines are pretty much synonymous with bodybuilding. A recent survey of 127 competitive bodybuilders found that every respondent trained with a split routine. Every one! Moreover, 2/3 of respondents trained each muscle only once per week (what is popularly known as a “bro-split”) and none worked a muscle more than twice weekly. The theory behind such routines is that growth is maximized by blasting a muscle with multiple exercises from multiple angles and then allowing long periods of recovery.
Things weren’t always this way, though.
Old-school bodybuilders such as Steve Reeves and Reg Park swore by total-body routines, working all the major muscles each and every session over three non-consecutive days-per-week. Proponents thought that the greater training frequency was beneficial to packing on lean mass.
Thing is, the choice to use one type of routine or another has been almost exclusively based on anecdote and tradition. Surprisingly little research has been carried out on the topic, and no study had directly compared muscle growth in a total-body routine versus a bro-split.
Until now.
My lab carried out a controlled experiment to investigate the effect of training frequency on muscular adaptations. The study was recently published in the Journal of Strength and Conditioning Research. Here’s the scoop.
What We Did
Nineteen young men with an average of more than 4 years lifting experience were randomly assigned to a resistance training program using either a total-body (all muscles worked in a session) or split-body routine (2-3 muscle groups worked per session). The program consisted of 21 different exercises spread out over a 3 day-per-week training cycle. The volume of the routines were matched so that both groups performed an equal number of sets and reps over the course of each week. All subjects performed 3 sets of 8-12RM per exercise. Training was carried out for 8 weeks. The table below shows the program design for both routines.
Subjects were tested pre- and post-study. We used B-mode ultrasound to measure the thickness of the biceps, triceps, and quads, and assessed maximal strength via 1RM for the back squat and bench press. Subjects were advised to consume their normal diets and we monitored food intake by analysis of a self-reported diary.
What We Found
Subjects in both groups significantly increased hypertrophy in the arm and leg muscles. That said, muscle mass increased significantly more in the biceps/brachialis for the group performing total body training compared with those in the split routine group. There was a trend for greater increases in the quads (i.e. vastus lateralis) and the effect size – a measure of the “meaningfulness” of results – markedly favored the total body group. Although no significant between-group differences were found in triceps thickness, the effect size again showed an advantage to total body training.
With respect to strength, both groups significantly increased 1RM performance in the bench press and squat from baseline. There were no significant between-group differences in either of these measures, although the effect size for the bench press did seem to favor the total body group.
How Can You Use This Info?
On the surface it would seem that a total-body routine is superior to a one-muscle-per-week bro-split for building muscle. All of the muscles we investigated showed greater growth from a higher training frequency. For the biceps, these results were “statistically significant,” meaning that that there was a greater than 95% probability that results did not occur by chance. While results in the quads and triceps did not reach “significance,” other statistical measures indicate a pretty clear advantage for the higher frequency routine. These results would seem to be consistent with the time-course of protein synthesis, which lasts approximately 48 hours (there is even some evidence that the time course is truncated as one gains lifting experience). Theoretically, repeated spiking of protein synthesis after it ebbs would result in greater muscular gains over time.
Before you jump the gun and ditch your split, a few things need to be considered when extrapolating results into practice.
First and foremost, it’s important to remember that the study equated volume between conditions. This was done to isolate the effects of frequency on muscular adaptations – an essential strategy for determining causality. However, a primary benefit of a split routine is the ability to increase per-workout volume while affording ample recovery between sessions. Since there is a clear dose-response relationship between volume and hypertrophy, total weekly volume needs to be factored into the equation. Certainly it’s possible that a split routine with a higher weekly volume would have performed as well or even better than the total body routine. Or perhaps not. We simply don’t know based on the current literature.
In addition, the vast majority of subjects in the study reported using a split routine as the basis of their usual workout programs, with muscles worked just once per week. This raises the possibility that the novelty factor of the total body routine influenced results. There is in fact some research showing that muscular adaptations are enhanced when program variables are altered outside of traditional norms. It’s therefore conceivable that participants in the total body group benefited from the unaccustomed stimulus of training more frequently.
Drawing Evidence-Based Conclusions
Given the available info, here’s my take on how the findings can be applied to your training program. There does seem to be a benefit to more frequent training sessions if max muscle is the goal. In this regard, it’s best to directly work each muscle at least twice a week; any less and you’re probably not stimulating protein synthesis frequently enough to optimize hypertrophy. Training each muscle three times a week, at least for periods of time, may provide additional benefits for spurring further gains.
Given the novelty factor, it’s reasonable to speculate that periodizing frequency over the course of a long-term training cycle might be the ideal option. Progressing from periods of working muscles twice to three times per week (and perhaps more) and then cycling back again will conceivably provide a novel stimulus that elicits continued gains. But remember: any discussion of training frequency must take total weekly volume into account. Greater training frequencies (from the standpoint of total training sessions per week) using a split routine can be employed to maximize total weekly volume and thus potentially drive greater hypertrophy over time.
It’s a commonly accepted tenet that resistance training adaptations follow a “strength-endurance continuum” whereby lifting heavy loads maximizes strength increases while light load training leads to optimal improvements in local muscle endurance. Conventional wisdom also postulates that at least moderately heavy loads are required for building muscle. General training guidelines proclaim that loads lighter than about 65% 1RM are insufficient to stimulate fast-twitch muscle fibers necessary for growth. The so-called “hypertrophy range” is generally considered to be 6-12 reps/set.
Recent research has challenged these established tenets. It has been proposed that if light loads are lifted to muscular failure, near-maximal recruitment of fast-twitch fibers will occur resulting in muscular adaptations similar to those obtained from training heavy.
A meta-analysis from my lab published last year in the European Journal of Sports Science found substantial increases in muscle strength and hypertrophy following low-load training. However, the magnitude of increases were not as great as that associated with using heavier loads, and a trend for superior gains was in fact shown when lifting weights >65% 1RM. I covered the specifics of this meta-analysis in a previous post.
The caveat: All previous studies employed untrained subjects, raising the possibility that results were attributed to the “newbie effect” that states those new to training build muscle from pretty much any activity — even cardio!
To achieve clarity on the topic, my lab carried out a well-controlled study on the effects of high- versus low-load training using resistance-trained individuals, which was just published in the Journal of Strength and Conditioning Research. Here’s what you need to know.
What We Did
Eighteen young men with an average of more than 3 years lifting experience were randomly assigned to a resistance training program using either moderately heavy loads (8-12RM) or light loads (25-35RM). All other aspects of the program were held constant between groups to isolate the effects of load on muscular adaptations. The program consisted of 3 sets of 7 different exercises targeting the major muscle groups (bench press, shoulder press, lat pulldown, seated pulley row, back squat, leg press, and leg extension). Training was carried out on 3 non-consecutive days-per-week (M, W, F) for 8 weeks.
Testing was conducted pre- and post-study. We used b-mode ultrasound to measure the thickness of the biceps, triceps, and quads. We assessed maximal strength via 1RM for the back squat and bench press. Finally, we measured changes in muscle endurance by having subjects perform the bench press at 50% of their 1RM to volitional failure.
What We Found
Both groups significantly increased lean mass in their biceps, triceps, and quads, but no statistically significant between-group differences were noted in any of these muscles (i.e. both groups had similar muscle growth over the course of the study). On the other hand, the heavy load group showed significantly greater strength increases in the back squat and a trend for greater increases in the bench press compared to the light load condition. Conversely, local muscle endurance was markedly greater for the low-load group.
Reconciling the Data
The primary take-home points from the study are as follows:
• Gains in muscle mass are about the same regardless of repetition range provided training is carried out to muscle failure
• Maximal strength requires the use of heavy loading
• Muscle endurance is best obtained from the use of light loads
To really understand the practical implications of the study, however, we need to look a bit deeper at the results.
The superior strength gains for heavy load training are consistent with the principle of specificity, which effectively states that training adaptations are specific to the imposed demands. No surprise here. From a mechanistic standpoint, the ability to exert maximal force has a high neural component, and the associated neural adaptations appear to be optimized through the use of heavy loads. Previous work from my lab showed that these adaptations exist even at the far left aspect of the strength-endurance continuum, as a powerlifting-type routine (3RM) was found to produce greater strength increases compared to a bodybuilding-style workout (10RM). It also makes intuitive sense that you need to train heavy to “get a feel” for using the maximal loads required to perform a 1RM.
The greater improvements seen in local muscle endurance from light-load training were expected as well. Although the topic hasn’t been well-studied, it stands to reason that low-load training is associated with adaptations specific to enhancing buffering capacity, thereby allowing for the performance of a greater number of submaximal repetitions. Again, a basic application of the principle of specifity.
On the other hand, I readily admit to being surprised by the fact that muscle growth was similar between conditions. While a number of previous studies had shown no differences in gains between light- and heavy-load training, I figured this was due to the “newbie effect.” No way could you build appreciable muscle using 30 reps per set.
Or so I thought.
I’m now a believer.
What’s particularly interesting, though, are the potential implications for how muscle growth actually manifests when training in different loading zones. A previous study from my lab showed that muscle activation was markedly greater when performing reps at 75% 1RM versus 30% 1RM. A follow up study (currently in review) found that the heavy-load superiority for activation held true when training at 80% 1RM versus 50% 1RM as well. Combined, these findings suggest that the recruitment and/or firing frequency in the high-threshold motor units associated with the largest type II fibers is suboptimal when training at low-loads. It therefore can be hypothesized that if muscle growth is indeed similar across loading zones — as found in the current study — hypertrophy from light-load training necessarily must be greater in the type I fibers. Indeed, emerging research out of Russia indicates that this is in fact that case with multiple studies showing that light loads promote greater gains in type I fibers while heavy loads increase type II fiber hypertrophy to a greater extent (Netreva et al 2007; Netreba et al 2009; Netreba et al 2013; Vinogradova et al 2013).
Bottom line: If your goal is to build as much muscle as possible, it seems appropriate to train across the spectrum of loading zones; use lighter loads to target type I fibers and heavier loads to target type IIs. In this way, you ensure maximal development of all fiber types.
An interesting point to keep in mind is that none of the subjects in my study trained with more than 15 reps/set during the course of their usual lifting routines and the majority never went above 10 reps. This raises the possibility that their endurance-oriented type I fibers were underdeveloped in relation to the strength-oriented type II fibers. If so, it’s possible that their type I fibers had a greater capacity for growth, which was realized in those who trained using light loads.
The study had some notable limitations. For one, the training period lasted only 8 weeks; whether results would have diverged over a longer time-frame is undetermined. For another, muscle thickness was measured only at the approximate mid-point of each muscle. Research has shown that muscles often hypertrophy in a non-uniform manner. Thus, it is possible that other aspects (i.e. distal or proximal) of the muscles studied might have differed in their growth response.
A final and important point to consider. While people often dismiss light-loads as being for wimps, nothing could be further from truth. Training to failure with high reps is highly demanding and the associated acidosis extremely uncomfortable. To this end, approximately half the subjects in the low-load group puked during the first week of training and several others experienced nausea and/or light-headedness. Although these issues tended to dissipate as time went by, they nevertheless can negatively affect adherence to the program. If you choose to incorporate light-loads into your program, be prepared for a grueling workout!
I recently collaborated with my colleague Menno Henselmans on a review paper that sought to provide clarity on the effects of rest intervals on muscle hypertrophy. Based on the current literature, we concluded that evidence was lacking to support the contention that rest interval length has an impact on growth. Problem is, there have been very few studies carried out to investigate the topic. Thus, it’s difficult to say with any degree of confidence as to whether there are or aren’t any benefits to varying how long you should rest between sets. For more on specifics of the review paper check out my blog post where it is discussed in detail.
Study Design
22 older men (mean 68 yrs) were recruited for participation. Subjects were healthy but were not involved in resistance training. All subjects underwent a 4-week “break in” phase where they performed a “hypertrophy-type” total body routine consisting of 2-4 sets of 8-15 reps per set. The subjects were then tested for various measures including strength and body composition, and then pair-matched based on 1RM bench press to perform an 8-week strength-type program with short rest (1 minute) or long rest (4 minutes) between sets. The strength-type routine consisted of 2-3 sets of 4-6 reps carried out 3 days a week. The exercises included leg press, flat bench machine chest press, lat pulldown, seated row, dumbbell step-ups, dumbbell Romanian deadlifts, knee extension, and knee flexion. Reps were performed with the intent to move the loads as fast possible while maintaining proper form. All sessions were supervised by trained personnel.
Results
Results were determined over the final 8-week strength phase of the program. Significantly greater increases in fat free mass (FFM), 1RM bench press, and 1RM leg press were noted for the short-rest group compared to those who took long rest periods. The researchers investigated a wide array of additional outcomes including power measures, which also generally favored the short rest group as well.
Commentary
Based on these results, it would appear that limiting rest between sets is beneficial to enhancing strength and hypertrophy. The increase in FFM for the short-rest group was 1 kg vs just a 0.3 kg increase for the long-rest group. The effect size — a measure of the meaningfulness of the results — was 0.37 indicating a fairly small effect. That said, a difference of 0.7 kg (equating to ~1.5 pounds) could certainly be meaningful for those seeking to maximize hypertrophy — particularly over a fairly short period (8 weeks). The effect sizes for strength were fairly large (0.65 and 0.76 for the 1RM bench and squat, respectively). Combined, these findings indicate that muscular adaptations are enhanced by taking short rest periods between sets.
But…a closer scrutiny of the study’s methodology gives reason for caution when drawing conclusions.
First and foremost, the researchers used DXA to measure body composition. The authors reported results for FFM, which as stated were higher for the short rest group. However, FFM encompasses all tissues in the body other than fat mass. This includes bone, connective tissue, and importantly water. You can probably rule out any differences associated with bone and connective tissue, which almost certainly would be minimal over an 8 week resistance training in terms of contribution to body mass. However, variances in water weight could easily have accounted for a large portion of the the reported 0.7 kg difference in FFM. It’s curious why the researchers did not choose to quantify the subject’s segmental muscle mass. There are equations that can be employed with DXA to obtain these values, which would have given a better sense as to true increases in muscle. Unfortunately, the reported data do not allow for a true understanding of changes in the lean component of body composition between groups.
Second, the subjects did not train to failure in either condition. The researchers stated that this was done to reduce neuromuscular fatigue and thus ensure that the subjects could tolerate the program over its duration. While I have no problem with that reasoning, it does raise a major issue: Since those in the short rest interval group had to lift again after only 60 seconds, they would have been taxed to a greater extent on each successive set. The long-rest group on the other hand would have sufficient time to recover prior to the next set, and thus would not have been substantially taxed at point during the workout. Now it is a bit difficult to determine how much the subjects were actually challenged on each set based on the study write up. Ideally the researchers should have quantified the level of effort exerted (perhaps by RPE or similar scale) to provide context. Without this info, I’m left wondering if the design was biased to produce a greater effect with shorter rest periods.
Finally and importantly, the study was carried out on elderly, untrained subjects. These individuals would no doubt have been sarcopenic, and their response to an exercise stimulus therefore would not necessarily mimic that of young, fit individuals. Thus, generalizability of results is limited to the population studied.
In conclusion, this is an interesting study that adds to the body of literature. However, caution must be exercised when attempting to draw conclusions as to the effects of rest interval length on muscular adaptations. The limitations of the study preclude extrapolation of results to those seeking maximal muscle mass.
The good news is that I am currently collaborating on a study on the topic that directly measures hypertrophy in well-trained subjects. Target completion for data collection is early next year. I will update when results are available.
It’s commonly taken as gospel that you need to warm-up prior to lifting. The warm-up contains two basic components: a general warm-up to raise core temperature, and a specific warm-up to heighten neural activation. The combination of these procedures is purported to enhance exercise performance. However, while research does seem to support this contention during maximal or near-maximal efforts, studies are lacking as to the effects of warming up during submaximal lifting routines.
To help determine the impact of warming up on a typical bodybuilding-style workout, I recently collaborated with colleagues in Brazil to carry out a controlled study on the topic. Here is an overview of the methodology and findings of the study, as well as its practical implications.
What We Did
Fifteen young men were recruited to participate in the study. Subjects were “recreationally trained” meaning they had limited lifting experience (resistance training for less than a year on average). Each subject performed 4 exercise sessions on separate days (48-72 hours between sessions) using the following different warm-up strategies prior to each workout: a general warm-up; a specific warm-up; a combination general and specific warm-up, or; no warm-up. In the aerobic warm-up subjects performed 10 minutes of light cycling exercise at a speed of 40 km/hr. For the specific warm-up, subjects performed a light set (10 reps at 50% 1RM) of the specific exercise before performance of that exercise. The order of the warm-ups was counterbalanced between subjects as shown in the accompanying figure to ensure that this variable did not unduly influence results. Exercise sessions consisted of 4 sets of the bench press, squat and arm curl at 80% 1RM. All sets were carried out to the point of muscular failure.
What We Found
There were no significant differences between the number of repetitions performed in any of the warm-up conditions nor was their a difference in the fatigue index, which is a formula that assess the decline in number of repetitions across the first and last sets of each exercise. In combination, these findings indicate that the warm-up procedures analyzed in this study had no effect on performance.
Practical Implications
At face value it would appear that a warm-up is pretty much useless prior to submaximal resistance training. Despite the currently held belief that warming up enhances exercise performance, no benefits were seen between either a general warm-up, specific warm-up or combination of the two compared to no warm-up at all. Intuitively this seems to make sense in that the initial repetitions of a submaximal lifts are in effect their own specific warm-up and the need to increase core temperature might be superfluous from a performance standpoint when multiple reps are performed.
When applying these results to practice, however, several factors must be taken into account. First, the subjects in this study were recreationally trained; although they had some experience with resistance training they were in no way highly skilled lifters. It certainly is feasible that those with extensive lifting experience who have highly developed neuromuscular patterns might benefit from even slightly increased neural responses.
Second, you need to take into account the type of exercise performed. To this point, there did seem to be a slight advantage to performing a specific warm-up in the squat (although it did not rise to statistical significance) while there actually seemed to be somewhat of a detriment to the specific warm-up in the biceps curl. Thus, more complex movement patterns would seem to benefit from the “practice effect” of a specific warm-up while this would be of no value during performance of simple exercises.
Third, the absolute amount of weight lifted also must be considered. A good case can be made that a specific warm-up would have more utility for someone benching 400 pounds as opposed to 200 pounds. Even though the “heaviness” of the load would be similar on a relative basis, the neural benefits of doing a lighter set would seem to have greater transfer when lifting the heavier absolute load.
Finally, we did not investigate safety-related issues of warming up — only performance-aspects were assessed. Although no subjects in this study were injured during testing, the sample was too small and the duration of the protocol too short to draw conclusions on the topic. While resistance training with submaximal loads generally has very low risk of injury provided proper form is maintained, there nevertheless exists the possibility that warm-up procedures could reduce the risk even further. This seems especially pertinent when working with high absolute loads.
The take-home message is to consider your own situation when determining whether or not to warm up prior to a submaximal lifting session. Yes, a warm-up does take a bit of time and you might be able to skip the procedure if you are time-pressed without enduring any negative effects on performance. This is particularly valid if you are less experienced at training and/or lifting fairly light loads. On the other hand, if you are a highly experienced trainee lifting heavy absolute loads then there very well might be a benefit to warming-up — this study certainly cannot be used as evidence to the contrary. Also, understand that research only reports the means (i.e. averages) between groups. There were in fact differences between responses whereby some subjects did show a beneficial effects from warming up while others did not. Only through individual experimentation can you determine if a warm-up enhances your own performance. Finally, there are potentially safety issues that were not studied here; a warm-up certainly would not seem to hurt in this regard and possibly could be of some help.
Reference
Ribeiro AS, Romanzini M, Schoenfeld BJ, Souza MF, Avelar A, Cyrino ES. Effect of different warm-up procedures on the performance of resistance training exercises. Percept Mot Skills. 2014 Aug;119(1):133-45.
Wanted to update everyone on all that’s been happening; so much to share!
First, I’ve agreed to write a textbook on muscle hypertrophy, to be published by Human Kinetics — one of the leading publishers on the science of exercise and nutrition. The book will be geared towards fitness professionals and university programs. I’m totally stoked to provide an evidence-based resource on a subject that has long relied on gym lore and bro-science. Estimated pub date is April of 2016.
I’ve also agreed to write a monthly column for Flex Magazine. The column will discuss science-based application of hypertrophy and fat loss practices. It’s a real kick for me to be a regular columnist for a mag that I grew up reading. My first column is slated for the November issue.
Research-wise, I’m currently finishing up a study on body comp changes associated with fasted cardio and another on muscle activation during different loading intensities in the bench press. During the fall I have multiple studies set to get underway including a training frequency study investigating muscular adaptations in split vs. total body routines, another comparing functional transfer between the squat and leg press, and yet another that will evaluate the effects of protein timing pre- versus post-workout on muscle hypertrophy in well-trained subjects. I look forward to sharing the results of these and other studies currently in review when they become available.
Okay, that out of the way, here are some links that I thought you’d find informative. As always, I appreciate your continued support.
• I recently lectured at the CanFitPro Conference in Toronto. While there, I got a chance to record a few interview segments for Omar Isuf’s YouTube channel. In this segment we discuss repetition ranges for maximizing muscle hypertrophy. Give this a watch and you’ll see why Omar lives up to his nickname, King of YouTube Fitness.
• I was interviewed along with my partner-in-science, Alan Aragon, on the We Do Science Podcast. Here Alan and I discuss the complexities of nutrient timing, delving into both the science and practical applications on the topic. Bonus discussion on a related topic: whether there is any fat loss benefit to doing fasted cardio. Click on Episode #8.
• I’ve appeared numerous times on Superhuman Radio; this segment might be my favorite yet. Here I discuss whether it’s possible to gain muscle simultaneously while simultaneously losing fat. Host Carl Lanore is consistently one of the best interviewers in the biz and he again shows why by asking all the right questions. l
• My friend and colleague Tom Venuto wrote an excellent post on delayed-onset muscle soreness and its relevance to muscular gains. The article covers the science in an understandable fashion, and provides solid take-home advice.
• Speaking of Tom Venuto, he wrote what I think is the most detailed review of my book, The M.A.X. Muscle Plan. Always an honor to receive praise from a true fitness pro such as Tom.
• In case you missed it, I recently published this study showing muscle activation during the leg press at 30% 1RM to failure produced significantly lower muscle activation compared to 75% 1RM. I also wrote an accompanying blog post where I break things down into consumer-friendly language and discuss the study’s implications.
• Finally, my good friend Bret Contreras wrote this terrific article that delved into the free-weights vs. machines debate. As mentioned earlier, I will be collaborating on a study examining this topic; Bret’s post provides excellent commentary on its complexities. While you’re at it, make sure to read through the references at the end of the article; it’s patently clear research doesn’t support the claims made by certain fitness pros.
Several months ago I wrote a blog post called A Dozen Must-Read Fitness Blogs. The post highlighted a number of blogs that I felt consistently put out great content on exercise and sports nutrition.
Recently, someone commented on the post asking why I didn’t include any blogs written by women. Hadn’t considered this point, but after giving it some thought I realized she was right! It was an oversight that needed to be addressed. Not that gender should make a difference when reading a blog — it’s the quality of course that counts regardless of who writes the post — but it’s nevertheless necessary to give credit where credit is due. Importantly, resistance training for women is an area that is still under-appreciated; the more we can do to make gals realize they need to embrace the iron, the better.
So I’m dedicating this post to feature some truly terrific female fitness pros and their respective blogs. When it comes to fitness, these gals get it. They’re not out there preaching that women should do endless reps with pink dumbbells and follow starvation diets. Quite the opposite, actually. They each have their own niche, but their philosophies are grounded in science and supplemented with a whole lot of good-old-fashioned in-the-trenches experience.
So without further ado, and in no particular, here are five must-read fitness blogs written by women for women (although most guys can certainly pick up a few pointers here as well). As with my previous post, this is by no means a comprehensive list. There are certainly a large number of other female bloggers that I’ve no doubt excluded and will look to cover in a follow-up blog.
• Jen Sinkler: Jen is a former rugby player turned fitness editor. She recently gave up her gig as the head honcho at Experience Life magazine to freelance at a number of the major women’s fitness mags and train clients one-on-one. Her blog is decidedly no-fluff. She focuses primarily on the performance-based aspects of lifting as opposed to training for aesthetics (although the two are not mutually exclusive). Articles are eclectic and range from areas as diverse as kettlebells to cycle circuits to biofeedback. Lots of good stuff.
• Molly Galbraith: Besides being one of the most down-to-earth individuals you’d ever want to meet, Molly is a true fitness pro. She was co-owner of a gym with Jim Laird where she specialized in working with female clients before recently stepping away to pursue online coaching and focus on maintaining her blog. Although the blog delves into a number of fitness topics, Molly’s focus is on helping women with body image issues. Her blogs are often very personal as she writes about her own struggles with body image and her journey to self-satisfaction through fitness. Moly is also co-founder of another excellent female-oriented blog, Girls Gone Strong that should be bookmarked for reading.
• Lift Like A Girl: This blog is written by Nia Shanks. Nia has a degree in exercise science and her in-depth knowledge of resistance exercise shows in her writings. Nia’s focus is on time-efficient workouts, particularly involving strength-based heavy-lifting routines. She covers aspects related to programming, technique and mindset. Some good nutritional articles as well. Lots of interesting reading. Make sure to watch her moonwalk!
• Flawless Fitness: This is Melody Schoenfeld’s blog. Full disclosure: Melody is in fact my sister. But before you claim nepotism, give her blog a read. Melody got her start as a trainer working in my gym back in the 90’s, then moved out to California to open her own facility. She tips the scales about 100 pounds but can out-lift a lot of guys (she holds several state powerlifting records). Her blog covers a wide range of topics. She’s big on kettlebells and holds certs as a master KB instructor. But she also gets into some cool alternative tools such as Indian clubs and even a medieval fighting implement called a mace.
• Stumptuous.com: This is Krista Scott Dixon’s blog. Krista can stake claim to being the original hard-core female fitness blogger and no doubt inspired many of the women on this list. She was churning out cutting-edge fitness articles around the turn of the century, telling women they should be squatting instead of performing a gazillion leg lifts. Her no-nonsense tone is refreshing, and she’s got a great sense of humor that makes her posts fun to read. Unfortunately, it seems Krista doesn’t post much anymore. The good news is that there is a ton of content on her blog that will keep you busy reading for weeks.
I’m stoked to announce that my dissertation study, Effects of different volume-equated resistance training loading strategies on muscular adaptations in well-trained men, was just published ahead-of-print in the Journal of Strength and Conditioning Research. I had actually devised the protocol during my master’s degree course in research methods back in 2008. The study I ultimately carried out had some different wrinkles than the one originally proposed, but overall the essence remained the same. Most importantly, it investigated a topic that’s been debated for many years: What are the differences in muscular adaptations (strength and hypertrophy) between bodybuilding- vs powerlifting-type training programs? Here is an overview of the study and a discussion on its practical implications.
The Methodology
20 well-trained subjects (minimum of 1 year resistance training experience working out at least 3 days/week) were recruited to participate in the study. Subjects were randomly assigned to one of two groups: A hypertrophy group (HT) that performed a bodybuilding style routine or a strength group (ST) that performed a powerlifting-style routine. The HT protocol was a split routine where each muscle was worked once per week with 3 exercises per session, performing 3 sets of 10 reps and resting for 90 seconds. The ST protocol was a total body routine where each muscle was worked 3 times per week with 1 exercise per session, performing 7 sets of 3 reps. The volume load (sets x reps x load) was equated so each group essentially lifted about the same amount of total weight per week. Training was carried out over 8 weeks. All sets were performed to the point of momentary concentric muscular failure.
Strength was measured by 1RM in the squat and bench press. Muscle thickness of the biceps was measured with ultrasound. Testing was carried out pre- and post-study, and results were then compared between groups to assess differences in strength and hypertrophy.
The Results
3 of the subjects dropped out of the study before completion leaving 17 subjects for analysis (9 in the HT group, 8 in the ST group). Both groups significantly increased biceps muscle thickness by ~13% with no differences seen between groups. Both groups also significantly increased 1RM strength, but the ST group had greater increases in the bench press and showed a trend for greater increases in the squat.
Practical Recommendations
On the surface, the study showed that muscle hypertrophy is similar between powerlifting and bodybuilding type routines provided that volume is equated between protocols. Moreover, the study showed that maximal strength is slightly greater in a powerlifting protocol. This could lead to the conclusion that if your goal is hypertrophy then it doesn’t matter what rep range you use (at least in the heavy to moderately-heavy range) as long as you perform equal volumes, but that maximizing strength requires lifting very heavy weights. From a mechanistic standpoint with respect to muscle hypertrophy, the study suggests that either 1) the increased mechanical tension in the ST group was offset by the greater metabolic stress in the HT group on a volume-equated basis or, 2) there is a threshold for mechanical tension and once the threshold is reached, it doesn’t matter as long as the stimulus is maintained for similar timeframes. With respect to strength, this would suggest that neural factors related to training are still relevant in well-trained individuals, and that using very heavy weights does indeed have a greater transfer to maximal lifts compared to moderate intensity loads.
But the devil is often in the details and that is the case here.
First, it is important to point out that total training time in the ST group was 70 minutes while that of the HT group was 17 minutes. So from a time-efficiency standpoint, the bodybuilding-type training produced similar hypertrophy (as well as nearly similar strength increases) in about a quarter of the time as the powerlifting routine. Moreover, exit interviews revealed that those in the ST group were fried by the end of the study. Almost all of them complained of sore joints and general fatigue, and the two dropouts from this group were because of joint-related injury (and these routines were highly supervised with respect to form, so we took every precaution for safety). On the other hand, the HT group all felt they could have worked substantially harder and done more volume.
This brings up an important take-away message: While mechanistically it appears that it does not matter whether heavy or moderately-heavy weights are used for hypertrophy, from an application standpoint it simply isn’t practical to train constantly with the volumes used in this study on multiple body parts. The grinding on the joints and the taxation of the neural system that is involved with repeated performance of very heavy loads ultimately has a negative impact on the lifter; I am certain that if we had continued this program for any longer, most of those in the ST group would have been overtrained and seen performance decrements. If nothing else, these finding reinforce the importance of periodizing programs so that cycles of deloading are interspersed with very heavy loading protocols.
Additionally, realize that only three major muscle groups were worked in the study: the pecs (upper body pushing); the back (upper body pulling) and the thighs. Thus, the HT group could have easily done a couple of extra sets for each muscle group without overtaxing their resources. Although impossible to say for sure, it certainly is plausible that additional work would have enhanced the hypertrophic response in the bodybuilding-style training group. Moreover, the HT group could have performed exercises for other muscle groups, including some targeted work with single joint movements. Working specific muscles (and aspects of muscles) such as the middle and posterior delts, the hamstrings and the calves alone would definitely have benefited overall muscle hypertrophy.
So bottom line: The study indicates that the best approach to building muscle is to perform a combination of heavy and moderately heavy loads. The “hypertrophy range” is applicable from the standpoint that it allows the performance of a greater amount of volume without overtaxing the body’s resources. Adding in loads in the 1-5 RM range can enhance strength (which ultimately allows the use of heavier loads during moderate rep lifting) as well as providing a potent hypertrophic stimulus.
It should be noted that.I made a conscious decision to investigate the two types of routines as lifters usually perform them. Thus, the HT routine was a split routine since the vast majority of bodybuilders train in this fashion, while the ST routine was a total body routine since this is the way most powerlifters train. While staying true to the usual performance gives insight into how muscular adaptations generally play out in everyday practice, they also obscure the ability to attribute results entirely to the set/rep scheme. I will be carrying out a follow up study that seeks to address this issue in the near future. Stay tuned!
Admit it. You’ve probably been lured into reading a magazine article with headline such as the one above. These types of claims are the norm rather than the exception in the muscle rags and fitness websites. And for good reason: the promise of a holy grail of workouts that will maximize your muscle development is an enticing prospect to say the least.
Problem is, no such routine exists.
It’s essential to realize that the response to resistance exercise is highly individual. Remember that research simply reports the means (i.e. averages). So if a study reports muscular growth after a given protocol as say 10%, you can bank on the fact that some subjects grew a lot more and some a lot less than 10%. Thus, you can’t simply extrapolate that you, or a client of yours, will achieve similar results to the reported mean.
Nowhere is this better illustrated than in a recent cluster analysis study by Bamman et al.. Sixty-six men and women performed supervised lower body exercise (squats, leg presses, and leg extensions) 3 days a week for 16 weeks. Training was carried out in typical bodybuilding-type fashion that included 3 sets of 8-12 reps for each exercise. At the end of the study, subjects were grouped by their hypertrophic response: The top 17 subjects were considered extreme responders. Their muscular gains averaged ~58%. Pretty awesome, right? The middle 32 subjects were considered moderate responders, with muscular gains averaging ~28%. Still pretty good, although well below the extreme responders. Here’s the kicker: the bottom 17 subjects saw, get this, NO significant gains after 16 weeks or consistent training. Zilch! Again, all subjects performed the exact same program but, as noted, saw widely disparate results. Based on the research, genetic factors are highly responsible for these differences, including the expression of various proteins (such as IGF-1) as well as satellite cell population. Lifestyle factors undoubtedly play a role as well.
Now the fact that people respond differently doesn’t discount that there are certain principles that should be inherent in any routine designed to maximize muscle-building. These include:
• Vary the loading strategies: Using different rep ranges (i.e. heavy, moderate and light) will ensure that you stimulate the full spectrum of muscle fiber types in a fashion that produces maximal growth. Recent work from my lab shows that light loads are suboptimal for fully activating the highest threshold motor units, but they may be superior for targeting the type I (endurance-related) fibers.
• Train with high volumes: There is compelling evidence that a dose-response relationship exists between volume and hypertrophy. Although a single set to failure can produce substantial increases in muscle growth, multiple sets are needed for maximal gains.
• Perform a variety of exercises: Muscles frequently have varying attachments and individual fibers are often compartmentalized so that they are innervated by different nerves. Research shows that a single exercise is not sufficient for maximizing whole muscle growth. To ensure complete muscle development, you need to have sufficient variety of exercise selection that takes into account basic applied kinesiological principles as outlined in my recent T-Nation article.
• Employ some sort of periodization scheme: This simply means that you need to manipulate variables over time. In particular, volume and training frequency should be varied over the course of training to prevent plateau. Ideally, volume/frequency should culminate with a relatively short training cycle designed to produce functional overreaching followed immediately by a period of deloading/active recovery. This will help promote a supercompensatory response that maximizes muscular gains. The process doesn’t have to be complicated; there are endless ways to go about periodizing a routine as long as you proceed in a logical fashion.
Given these basic tenets, it is essential that you take individual differences into account when designing training programs. There are no cookie-cutter prescriptions for getting big. For those familiar with my book, The M.A.X. Muscle Plan, you’ll know that I reinforce this concept repeatedly throughout the text. That’s why I refer to the book as a “template” for success; optimal benefits can only be achieved by customizing the program to your own personal needs and abilities.
Bottom line: There is no “best” muscle-building program; only a best program for a given individual.
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