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.
One of the most widely held exercise beliefs is that you should never let your knees go past your toes when squatting. You’ll hear this “rule” echoed like a mantra over and over by the majority of personal trainers: “Keep the knees behind the toes!”
Fact is, though, there’s little evidence to back up such a claim. It is true that as the knees move anteriorly (i.e. forward) during the squat, the forces acting on the knee joint increase. However, there is no “magic point” where these forces suddenly become dangerous. The plane of the toes has been misguidedly used as a line of demarcation despite a complete lack supporting research. What’s more, intentionally preventing the knees from going past the toes can create additional problems at other joints that are potentially more injuries.
An eloquent study by Andy Fry and colleagues (2003) looked at this very topic. Seven recreationally-trained males performed 3 unrestricted squat lifts and 3 restricted lifts where a wooden board was placed immediately in front of both feet so that the knees were prevented from moving forward past the toes. As expected, knee torque was greater when the knees went past the toes compared to restricted squatting (~150 vs. 117 newton-meters). Sounds like intentionally keeping the knees behind the toes is a good thing, right? Not so fast…
Restricted squats resulted in significantly greater torque at the hip joint compared to unrestricted squatting, with the differences here much greater than those seen at the knee joint (302 vs. 28 newton-meters). Perhaps even more problematic is that results were attributed to a greater forward lean when performing restricted squats. Why is this an issue? Well, in order to squat while keeping knees behind toes, lifters tend to compensate by increasing their forward lean. Studies have shown that an increased forward lean is associated with greater lumbar shear forces. And since the lower back is more susceptible to injury than other joints, this would seem to be a poor tradeoff.
So what’s the take home message? I’ll quote directly from the Fry et al. study as they sum things up very nicely: “While it is critical to protect the knees from unnecessary forces, it is also important to avoid unnecessary forces acting at the hips. These hip forces will ultimately be transferred through the lower back and therefore must be carefully applied. The net result is that proper lifting technique must create the most optimal kinetic environment for all the joints involved. Exercise technique guidelines should not be based primarily on force characteristics for only one involved joint (e.g., knees) while ignoring other anatomical areas (e.g., hips and low back).”
I would note that the same rules do not apply for lunges. Since the lunge involves stepping forward, there is no issue with maintaining an erect posture during performance. The biggest mistake I see is that people tend to push forward on their front leg, which significantly increases shear at the knee joint. Instead, your focus should be centered on dropping the rear leg. In doing so, your front leg will stay perpendicular to the ground, minimizing stresses to the knee joint without negatively impacting the hip or the spine.
Stay Fit!
Brad
Fry AC, Smith JC, Schilling BK. (2003). Effect of knee position on hip and knee torques during the barbell squat. J Strength Cond Res. 17(4):629-33.
Here’s one of my favorite single-joint movements to target the quadriceps. It’s called the sissy squat but it’s definitely not for sissies! You can add resistance by holding a weighted plate or dumbbell against your chest. Alternatively, try supersetting the movement with a multi-joint movement such as a squat, lunge, or leg press. Very effective quad builder!
In a blog post titled, What’s Your Squat IQ?, the Cooper Institute did a solid job providing practical applications for squatting based on my recent review article appearing in the Journal of Strength and Conditioning Research. However, one issue I have with the article was the recommendation that “if you can’t see your toes” when squatting then “you need to sit back more.” The general idea behind the advice is sound. Certainly you should try to minimize forward translation of your knees as much as possible to decrease forces acting on the knee. But this should not be done at the expense of greater forward lean, which significantly increases stresses on the lower back region–an area that is highly susceptible to injury. Moreover, the belief that you’ll somehow damage your knees as soon as they go past your toes during the squat is not supported by research. Ultimately body type will dictate squatting kinematics and some people simply will not be able to maintain a position where the knees stay behind the plane of the toes. Provided you do not have existing knee pathology, you shouldn’t worry about this as the detrimental effects of knees-over-toes during the squat are overstated.
1. Squat depth should be consistent with the goals and abilities of the individual. Because peak patellofemoral compressive forces occur at or near maximum knee flexion, those with patellofemoral disorders should avoid squatting at high flexion angles. For those with existing injury or previous reconstruction of the PCL, it is best to restrict flexion to 50° to 60° so that posterior shear is minimized. Quadriceps development is maximized by squatting to parallel, with no additional activity seen at higher flexion angles. Hip extensor moments increase with increasing squat depth, so full squats may be beneficial for those seeking to maximize strength of the hip musculature.
2. Speed of movement should be based on goal-oriented specificity to the force-velocity curve. However, given that speed of movement has been shown to significantly increase both compression and shear forces, there is a tradeoff between optimal transfer of performance and risk of injury. This is especially true on the eccentric aspect of the move where rapid deceleration generates exceedingly high joint forces at the knee. Failure to control descent can result in the ballistic contact between the hamstrings and calf muscles, which can cause a dislocating effect on the knee ligaments. Therefore, unless athletic goals specifically dictate otherwise, squat descent should always be executed in a controlled fashion, with a 2 to 3 second eccentric tempo considered a general guideline.
3. A wider stance squat is preferable for those seeking optimal development of the hip adductors and hip extensors, whereas a closer stance is more appropriate for targeting development of the gastrocnemius. Stance can also be varied to alter joint-related forces: a narrow stance helps to minimize patellofemoral and tibiofemoral compression while a wider stance results in less forward knee translation and thus reduces shear.
4. Low bar back squats tend to produce greater hip extensor torque and less knee extensor torque compared with high bar back squats. However, the magnitude of forces for both movements are well tolerated by the associated joint structures, making either position suitable for the majority of lifters. The front squat produces significantly lower knee compression and lumbar stress in comparison with back squats, making it a viable alternative for those suffering from various knee and back ailments. Front squats also can be particularly beneficial for those competing in weight lifting events because it is an essential component in performance of the clean.
5. Fatigue can have a deleterious effect on squatting technique, potentially leading to knee instability and increased lumbar shear. If the lifter opts to squat to momentary muscular failure, it is advisable to have a spotter to ensure safety.
In addition to the aforementioned joint-specific recommendations, some joint-specific recommendations can be made as to squat-related performance variables.
Ankle Joint: Significant strength and mobility is required at the ankle for proper squat performance. Feet should be positioned in a comfortable stance that allows the knees to move in line with the toes. Because the feet are outwardly rotated approximately 7° in anatomic position, this can be considered a good starting point to ensure proper patellar tracking. If the lifter’s heels rise off the floor during the eccentric phase of movement, efforts should be made to improve flexibility around the talocrural and subtalar joints. Orthotics can be worn to help correct joint imbalances and misalignment. If necessary, a barbell plate or other flat object can be placed underneath the heels to aid in stability.
Knee Joint: Given the fact that shear forces are increased as the knees move past the toes during the downward phase of the squat, attempts should be made to avoid significant forward knee translation on descent. However, this should not be done at the expense of compromising form at the hips and spine, which can place the lumbar region in a biomechanically disadvantageous position and significantly increase spinal shear. To reduce tibiofemoral and patellofemoral moments, the lifter should sit back into the squat during descent and resist pushing the knees forward. There should be no varus or valgus motion throughout exercise performance.
Hip Joint: Given the close relationship between movement at the hips, pelvis, and lumbar spine during dynamic squatting, hip mobility is extremely important for proper squat performance, especially at higher flexion angles. Poor joint mobility can lead to greater forward lean and thus increased spinal shear. Although some lifters attempt to increase hip flexion by using posterior pelvic movement during squat descent, this can heighten lumbar stress and is thus not advisable. Flexibility training specific to the hip musculature can help to increase hip mobility and facilitate better squat performance.
Spine: The spine is the most vulnerable of the joints during squatting. Because the lumbar spine is better able to handle compressive force than shear, a normal lordotic curve should be maintained in this region, with the spinal column held rigid throughout the movement. Proper spinal alignment is facilitated by maintaining a straight ahead or upward gaze, which reduces the tendency for unwanted flexion. Although some forward lean is sometimes necessary to maintain stability especially when performing deep squats, attempts should be made to keep the trunk as upright as possible to minimize shear. No lateral movement should take place at any time.
I recently was asked to write a paper for the NSCA Hot Topic series, and decided to address one of the most controversial subjects in the fitness field: namely, are full squats bad for your knees? As I detailed in the article, the answer is no, deep squats do not pose increased risk of injury to the knees *provided* you have no existing knee issues. Without question, deep squats may be contraindicated for those with knee pathology depending on the extent of the injury (it should be noted that any exercise may contraindicated because of injury). If you fall into this category, a qualified physician specializing in sports medicine should be able to assess what you can and can’t do. Otherwise, squat depth should not be an issue from an injury perspective. In fact, the deeper range of the squat is actually protective of many of the knee structures!
Assuming you have healthy knee function, what you should in fact consider with respect to squat depth are your goals. Deep squats have relevance to various sports, as well as many activities of daily living. These are powerful reasons why you would be well served by squatting as low as possible, at least on some of your sets. What’s more, glute involvement increases the lower you go in a squat. This means that if you want to maximize the development of your butt, then deep squats are highly beneficial. On the other hand, quadriceps development is greatest squatting to parallel. So if you are most concerned with developing your frontal thighs, deep squats might not be a necessity.
The bottom line is, don’t be afraid to squat low as long as you don’t have any existing knee problems. Make a decision based on your goals, not fear of injury. If you’re interested in reading about the science on the topic, you can check out my Hot Topic article at the link below.
Fact: Studies have repeatedly shown the squat to be a safe, effective exercise; when performed properly, it poses little risk to those who have healthy patellar function. Even elite athletes who squat several times their bodyweight have few reported injuries directly attributable to the activity.
Squatting actually places less stress on the knee joint than leg extensions. This has to do with the way that force is applied during exercise performance. In the leg extension, loading is applied perpendicular to the long axis of the tibia—a fact that creates tremendous shear force in the patellar region. Alternatively, loading during the squat involves a high amount of compression (i.e. a “squeezing” force), with forces applied parallel to the long axis of the tibia. Since a joint is better able to withstand forces from compression as opposed to shear, it therefore follows that squats are more joint-friendly than leg extensions.
What’s more, leg extensions tend to overstress the anterior cruciate ligament (ACL). During performance, the quadriceps reacts by pulling the tibia forward (a phenomenon called tibial translation). The ACL in turn opposes the quadriceps by trying to prevent translation of the tibia. These two antithetic actions place a considerable amount of stress on the ACL, and can potentially injure the ligament (and other soft tissue structures, as well).
Squats, on the other hand, have somewhat of a protective effect on the knee ligaments. Due to the multi-joint nature of the squatting movement (both the hip and knee are involved in performance), the hamstrings are activated as co-contractors and exert a counter-regulatory effect on the pull of the quadriceps. The co-contraction of the hamstrings and quads help to neutralize tibial translation, alleviating stress on the ACL.
All things considered, squats shouldn’t be avoided by those with healthy knees. They are a terrific exercise that works not only the lower body, but a significant portion of the torso, as well. It’s estimated that squat performance involves the recruitment of over 200 muscles in total, including the assistance of many stabilizer muscles. Without the active participation of these stabilizers, the act of squatting simply cannot take place. Hence, while the glutes and thighs are the prime muscle movers, synergistic muscle action is derived from the abdominals, spinal erectors, rhomboids, trapezius and other muscles. Squats therefore have a systemic effect on anabolism, helping to promote overall muscular development.
Further, the squat is an extremely functional exercise. It is used in many activities of daily living. Any time you lift an object from the floor (or sit in a chair, for that matter!), squatting is involved in the movement. Consequently, squats can help build the kind of practical strength and kinesthetic awareness that facilitates better performance of everyday tasks. In many cases it can even help to prevent lifting-related injuries at home and in the workplace.
Now this is not to say that squats are appropriate for everyone (in actuality, there is NO one exercise that is appropriate for everyone!). Conditions such as degenerative arthritis and various connective tissue disorders can be contraindications for squatting movements. But it’s not the squat, per se, that is harmful here: any form of loaded (or even unloaded) knee flexion and extension can exacerbate a patellar-related injury. Hence, it you have pre-existing knee pathology, caution must be utilized in both the choice and execution of thigh exercises. But provided no contraindications exist, you should have no problem squatting on a regular basis. It’s one of the best exercises you can do for both your body and your health!
Here’s a great exercise to sculpt the thighs. It’s called the sissy squat, and it is particularly good for developing the upper portion of the thighs, as it targets the rectus femoris—the only quadriceps muscle that crosses the hip joint. Perform the sissy squat as follows:
Begin by taking a shoulder-width stance. Grasp an incline bench with one hand and rise up onto your toes. In one motion, slowly slant your torso back, bend your knees and lower your body downward. Thrust your knees forward as you descend and lean back until your torso is almost parallel to the floor. Do not allow your butt to drop below your torso. Then, reverse direction and rise upward until you reach the starting position.
Want to see an animated demonstration of the sissy squat, then Click Here to visit the exercise database section of my site.
Stay Fit!
Brad
TAGS: thigh exercises, sissy squats, rectus femoris, lower body exercises
Deloads, defined as a “period of reduced training stress,” are a popular strategy designed to attenuate accumulated fatigue and diminish the potential for nonfunctional overreaching after a period of intense training. Although deloads are often implemented by reducing training volume and/or intensity, by definition they can be employed as a relatively brief period of complete training cessation (i.e., detraining periods) to facilitate recovery.
Intriguingly, some evidence suggests that short-term detraining can potentially “resensitize” muscle tissue to potentiate anabolism. For example, a recent study showed that anabolic intracellular signaling was blunted after a 4-week resistance training program; however, signaling was restored to baseline levels after a 10-day cessation from training. Other research indicates that brief detraining periods can upregulate genes associated with muscle hypertrophy and increase testosterone levels, which conceivably could enhance muscle development.
However, acute findings do not necessarily translate into long-term gainz. No previous study had endeavored to investigate whether deloads actually enhance muscular adaptations, making any conclusions on the topic speculative…
Until now…
Our lab set out to assess the effect of deloads, when implemented as a brief period of detraining, on measures of muscular strength, hypertrophy, power and endurance. The study was led by our grad student, Max Coleman, who carried out the investigation in completion of his master’s thesis.
If you want to delve into the fine points of the methods and findings, you can read the study here. Alternatively, if you prefer a consumer-friendly synopsis, here’s the scoop…
What We Did
We recruited 50 resistance-trained men and women to perform a 9-week training program; participants were randomized to either perform the entire training program consecutively over the 9-week period (TRAD group) or to train for 4 weeks, take a 1-week layoff, and then train for another 4 weeks (DELOAD group).
The training program was the same for both groups, comprising 4 weekly sessions structured as an upper-lower body split. Our research staff directly supervised the lower body portion of the program, which included 5 sets of the squat, leg extension, straight-leg calf raise and bent-leg calf raise per session. We provided participants with an upper body program to perform on their own, which included 5 sets of shoulder press, lat pulldown, chest press, biceps curl and triceps pushdown per session; participants provided written logs of their sessions to the research staff on a weekly basis. Participants carried out all sets to failure in the supervised sessions and were instructed to do the same for their unsupervised sessions.
We assessed the following measures before and after the training program: (1) body composition via bioelectrical impedance analysis; (2) muscle thickness of the mid- and lateral quadriceps (upper, mid and lower sites) and the calves (medial and lateral gastrocnemius and soleus) via ultrasound; (3) lower body maximal strength in the squat via 1 repetition maximum testing and isometric knee extension via dynamometry; (4) lower body muscular power via the countermovement jump test; (5) lower body muscular endurance (AMRAP) via the leg extension using 60% of the participant’s initial weight. We also employed a readiness to train questionnaire that subjectively assessed participants’ feelings about the training program across the study period.
What We Found
Although both groups increased their strength from pre-study testing, gains were modestly greater in the TRAD group. Specifically, 1RM squat and isometric knee extension favored TRAD by 4.5 kgs and 11.5 newton-meters, respectfully. Notably, all other measures of body composition, hypertrophy, power and muscular endurance were relatively similar between groups.
What Do the Results Mean?
Contrary to what some may have expected (including me), the deload did not have a appreciable beneficial effect on muscular adaptations. In fact, there was a modest negative effect on maximal strength gains. Even though we pushed the participants really hard, verbally encouraging them to reach muscular failure on each set in a routine that could be considered of moderately high volume (90 total sets per week), the deload period did not seem to facilitate rejuvenation, nor was there evidence of a “resensitization” of muscle for anabolism. On the surface, some may interpret this to mean that deloads are useless.
But hold on…
The results of a study can only be extrapolated to the specifics of the methodological design. To this end, there are a number of factors that must be considered when attempting to draw practical conclusions:
1. The deload employed a complete cessation of training for one week. As mentioned, we used this approach based on evidence that there can be a “resensitization” of muscle after a short period of detraining, thereby enhancing anabolism. However, a popular alternative strategy is to deload with a reduced volume/intensity/frequency of training. There are numerous ways in which such a strategy can be implemented. We thus cannot necessarily extrapolate the findings to other deload approaches.
2. The study employed a deload after four weeks of intense training, regardless of whether participants felt they needed one. Although the findings indicate that deloads may not be beneficial after this relatively short period of time, it does not necessarily mean that continued intense training may not benefit from deloads over longer time frames.
3. To provoke overreaching and thus create a potential need for deloading, we employed what many would consider a relatively high-volume training program (90 sets per week) with all sets performed to volitional muscle failure. However, we only supervised the lower body portion of the training program. Although we received weekly training logs from each subject to verify their upper body progress, we do not know how intensely they trained. Based on my experience, I’d say it is highly likely that the majority of participants did not train as hard during their unsupervised training sessions as in their supervised sessions, conceivably reducing the need for a deload. Moreover, many bodybuilders perform substantially higher total training volumes, which may necessitate more frequent deloads. These factors warrant further study.
4. The participants were all young adults (average age ~22 years). It is well-established that recovery needs increase as we age. Thus, we cannot necessarily generalize the results to those 40+ years of age, who conceivably may benefit from periods of reduced training.
5. Although the participants all had at least a year of resistance training experience (average of ~3 years), they would not be considered elite lifters or bodybuilders. It’s conceivable that very advanced lifters may require more recovery due to the use of very high absolute training loads. This would particularly be the case for powerlifters and other strength-oriented athletes, who grind out reps with heavy compound lifts (our study employed a moderate rep range typical of bodybuilding programs) and thus may experience joint-related issues as well as central nervous system fatigue if recovery is not well-managed.
Take-Home Conclusions
The findings of our study can be looked at from a couple of different perspectives. On one hand, the deload had no detrimental effects on muscle development. In this context, you can take a week off every month or so and have peace of mind that you’ll maintain your muscle mass. Essentially, you can do less work over time without suffering negative consequences from a physique standpoint. Alternatively, if your goal is to maximize strength, this may somewhat hinder results.
On the other hand, there is seemingly no benefit to take regimented deloads every four weeks. Based on our research, it appears that most would not need a deload for at least 8 weeks if not longer, although this would ultimately vary from person to person.
I’d note the study has caused me to question my previous opinion on the implementation of deloads. I was of the belief that lifters generally do not have a good grasp of their recovery requirements, and thus they would only realize the need for a deload after they were nonfunctionally overreached. I thus advocated for deloads every month or so after a period of intense training to ensure recovery and rejuvenation.
Our study indicates this belief was unfounded.
Virtually every lifter stated they did not feel the need for a recovery week at the end of the 9-week study period, including those in the group that didn’t deload, and this seemed to play out in the results. So contrary to my thought process, it would seem that experienced lifters can in fact sufficiently gauge their need for recovery. Thus, my opinion has now shifted to recommend autoregulated deloads, where lifters implement a deload when they feel they need one. This hypothesis remains to be studied.
If you want to delve into the fine points of the methods and findings, give the paper a read. For those who’d prefer a consumer-friendly synopsis, here’s the scoop…
What We Did
We randomized 45 young, resistance-trained men and women to perform a total-body resistance training program either in a supervised (SUP) or unsupervised (UNSUP) manner across an 8-week study period. Both groups performed the exact same exercises (front lat pulldown, machine shoulder press, machine chest press, cable triceps pushdown, dumbbell biceps curl, plate-loaded leg press, machine leg extension and machine leg curl) and program variables (3 sets of 8-12 RM for each exercise with 2 minutes rest between sets).
Participants in SUP were directly supervised throughout each rep of every session, with researchers verbally encouraging them to carry out all sets to volitional failure (i.e., the point where an individual felt that he/she could no longer complete an additional repetition) and adjusting exercise technique when appropriate. Alternatively, those in UNSUP were taken through an acclimation session to demonstrate proper technique on the given exercises and instructed to carry out all sets to volitional failure throughout the training program; they charted their workouts and emailed the corresponding logs to the research staff on a weekly basis.
We assessed the following measures before and after the training program: (1) body composition via bioelectrical impedance analysis; (2) muscle thickness of the biceps, triceps, and quads via ultrasound; and, (3) maximal strength in the bench press and squat via 1 repetition maximum testing.
What We Found
In regard to hypertrophy, the SUP group showed greater increases in muscle thickness for the triceps brachii, the upper portion of the lateral thigh and all regions of the mid-quadriceps. Alternatively, the biceps brachii and mid- and lower aspects of the lateral thigh showed relatively similar hypertrophy between groups.
From a strength standpoint, the SUP group showed greater increases in the 1RM squat; increases in the 1RM bench were relatively similar between groups.
Of note, there were a considerably greater number of dropouts in UNSUP (n=7) compared to SUP (n=2) across the study period.
What Do the Results Mean?
Overall, the findings indicate that direct supervision has a beneficial effect on strength and hypertrophy in recreationally trained young men and women. The magnitude of the effects ranged from relatively small to quite large, suggesting that adaptations could be practically meaningful.
Although we did not attempt to explore the underlying mechanisms for results, it can be hypothesized that intensity of effort was a contributing factor. There is compelling evidence that training with a high level of effort is necessary to optimize muscular gains. Not only did our research team verbally coach participants to go to failure on each set, but findings also may have been influenced by the fact that people try to do their best when being observed (the so-called “Hawthorne Effect”). Notably, when asked about their perceived effort at the end of the study, almost all participants said they trained harder than they ever had before. This would suggest that those in the UNSUP group were generally training with less effort, perhaps below the threshold required for max gainz.
Results also may have been partially attributed to improved training technique. Although the participants all had been training consistently for at least one year, some did not perform exercises in a biomechanically efficient manner and/or did not properly control the weights throughout each repetition (especially on the eccentric action). For those in the SUP group, our research team corrected technique during a set when appropriate, helping to ensure that muscles were optimally stimulated. We can only speculate on the matter, but it’s reasonable to assume that a number of participants in the UNSUP group likely trained with substandard technique, potentially diminishing results.
Another important finding was that the UNSUP group had far more dropouts than the SUP group. At the end of the study, several participants in SUP stated that the supervision made them feel “accountable” to show up for the training sessions. Considering that exercise adherence is paramount to achieving results, supervision would thus be beneficial to a substantial portion of the general population who are not sufficiently motivated to train consistently.
Take-Home Conclusions
So what are the practical implications of these findings?
On a general level, direct supervision during resistance training appears to enhance muscular adaptations for a majority of the recreationally trained lifting public. The supervision could be in the form of a qualified personal trainer or attentive workout partner; essentially, someone who monitors exercise technique and suggests corrections where appropriate and motivates the lifter to push sufficiently hard during each set. Given that individuals who are relatively new to resistance training generally have spotty technique and perhaps a poor understanding/motivation to progressively challenge their muscles, they may benefit to an even greater extent from a supervised program. Alternatively, some advanced lifters (i.e., bodybuilders, etc) may be internally motivated to consistently train with high intensities of effort and hence may not meaningfully benefit from supervision.
The results also suggest that research studies intending to investigate the efficacy of resistance training-induced strength/hypertrophy outcomes should carry out data collection in a supervised environment; it’s the only way to ensure that participants train in a manner consistent with optimizing results. However, while this approach may enhance research efficacy, there may be a disconnect when generalizing the findings from resistance training research carried out under supervision to the recreational lifting public. Namely, if most lifters train suboptimally on their own, they cannot necessarily expect to achieve results similar to those found under supervised conditions. The tradeoff needs be considered by researchers when designing resistance training interventions as well by practitioners when interpreting study findings for program prescription.
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