Exercise, Strength Training

May 9, 2015

Does Light Load Training Build Muscle in Experienced Lifters?

Strength endurance continuum
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!


  1. Excellent blog and research Brad. This is something I’ve continued to be interested in and your writing on this is excellent. When I was a less experienced personal trainer, I worked with many clients aged 40-60 in the traditional 6-10 reps per set range. Over time, I feel that I’ve seen more tendinitis type issues in that range so many clients stay in a 10-20 rep range for most training with a minority of the time between 6-10 reps. Although I’ve seen less tendinitis issues in this higher range, I’ve accepted that the strength gains in the higher range won’t be as impressive. At least it seems that the hypertrophy gains are somewhat similar. Keep up all the great work Brad.

    Comment by Doug Jackson — May 10, 2015 @ 8:00 am

  2. Thanks Doug. Cheers!

    Comment by Brad — May 11, 2015 @ 8:28 pm

  3. I wonder then if the typical hypo range (6-12) is too middle of the road? Should we be looking at the ends of the spectrum instead of the middle?

    Comment by bmanMA — May 12, 2015 @ 8:06 am

  4. 8-12 in above (type-o).

    Comment by bmanMA — May 12, 2015 @ 8:08 am

  5. Good stuff Brad. I’ve been lifting @30RM for months now & my aches & pains from lower rep lifting have almost completely disappeared. Different mindset though w/high reps which I found difficult at first but now enjoy.

    Comment by Baker — May 13, 2015 @ 12:39 pm

  6. Very interesting research. I have a question regarding time under tension.
    What about doing reps with a slow negative and fast positive compared to “standard” faster reps?
    Time under tension could be the same, but the weights being used heavier?

    Would there be a difference in result?

    Comment by Paul — May 14, 2015 @ 8:31 am

  7. That’s why I change reps between weeks. One heavy week, next one high-reps. Seems to be working fine.

    Comment by xPrzybyLx — May 15, 2015 @ 9:02 pm

  8. […] Does Light Load Training Build Muscle in Experienced Lifters? — Brad Schoenfeld […]

    Pingback by Best Fitness Articles - May 17, 2015 - Personal Trainer Development Center — May 16, 2015 @ 10:12 am

  9. […] Does Light Load Training Build Muscle in Experienced Lifters? via Brad […]

    Pingback by Good Fitness Reads of the Week: 5/17/2015 - adampine.com — May 17, 2015 @ 9:17 pm

  10. Doesn’t time allotted and the ability to adhere to the training plan play a factor in the long term results ? I mean, who has time to perform sets of 35 reps and will that impact a person from wanting to train ?

    Comment by Steven — May 18, 2015 @ 4:57 pm

  11. Assuming rest intervals remain constant, then performing 30 reps vs. 10 really would only add 15-20 minutes at most on to your workout time. Conceivably you could also do fewer sets with the lighter load since the volume (i.e. reps x sets) is naturally higher.

    Comment by Brad — May 20, 2015 @ 3:35 pm

  12. Hey Brad, was the rep tempo the same for both groups?

    Comment by RKC — May 29, 2015 @ 4:42 am

  13. As you get older it would be advisable
    to train in the 20-30 rep range. At the age of 60 I was reluctant to try it since I was so conditioned to train in the low rep range. Now I know how much tougher it is to workout in the higher rep range plus you gain more metabolic benefits. By the way I was a member of World Gym for 35 years when it first originated on Main street in Santa Monica and contrary to what you might have heard or read then many professional bodybuilders train in the high rep range such as Frank Zane, Greg DeFerro, Serve Nubret and many others. I remember training with Nubret doing sets of 100 rep squats with just your bodyweight. In most cases most bodybuilders used the pyramid set protocol with most exercises something like 20 15 12 10 8 6 adding weight with each set.

    Comment by Philippe — June 9, 2015 @ 9:55 pm

  14. Brad!You need to adjust the volume when you do higher rep protocol. Lets assume you do 15 sets of 10 reps over three movement for a certain body part jumping to 20-30 rep sets would be too much initially, we are now talking between 300-450 reps, even once a week that’s an amount of volume that one needs to work up to over months.

    Comment by Philippe — June 9, 2015 @ 10:09 pm

  15. Scott Abel uses a wide variety of rep ranges in his “Hypertrophy for Ectomorphs” program. Quite a bit if time is spent in the 15-20 rep range, along with some medium and lower rep work. I experienced the best gains of my career with this type of training. It gives a bit of everything – but it is a demanding way to train – it is necessary to ease into it gradually in my opinion.


    Comment by Colin — July 26, 2015 @ 6:02 pm

  16. […] show that you can make muscle gains training in any rep range as long as you’re progressing (low load, medium load, and high load). But results are not equal in all situations. The medium rep ranges […]

    Pingback by Best Rep Range for Muscle Growth – How heavy should you train? | — August 1, 2015 @ 5:21 am

  17. I don’t know much about this, but aren’t the associated acidosis that one get when training close to or to failure with high reps pretty catabolic?

    Comment by John — October 21, 2015 @ 10:03 am

  18. […] From Dr Brad Schoenfeld: […]

    Pingback by Why You Can Build Muscle with High Reps — November 2, 2015 @ 3:01 pm

  19. […] is some research to suggest that lighter weights and higher reps promote greater gains in type I muscle fibres. […]

    Pingback by Heavy Weights for Big Gains — November 18, 2015 @ 2:17 pm

  20. […] while there are certainly benefits to doing work in high rep ranges, the primary goal of Gary’s training is to get stronger in the 4-6 rep […]

    Pingback by Gary Vaynerchuk's Exact Training Program — November 23, 2015 @ 11:11 am

  21. […] muscle and losing fat) involves several different factors and can be achieved in different ways. High or low reps can achieve muscle growth, as long as the effort is […]

    Pingback by Do High Reps Get You Toned? – — January 16, 2016 @ 10:37 pm

  22. What was the starting stats and ending stats of the participants?

    Comment by Alex C — April 4, 2016 @ 12:12 am

  23. Alex:

    The results are detailed in the paper. You can download the full text from my Researchgate page at the following link: https://www.researchgate.net/profile/Brad_Schoenfeld/publications?

    Comment by Brad — April 4, 2016 @ 7:32 pm

  24. […] http://www.lookgreatnaked.com/blog/does-light-load-training-build-muscle-in-experienced-lifters/ […]

    Pingback by BEST REP RANGE FOR MUSCLE GROWTH – RCT Official / Chesteezy Gaming — June 17, 2016 @ 1:16 am

  25. Keep Your Load Light But The Style

    […] in the high rep range such as Frank Zane, Greg DeFerro, Serve Nubret and many o […]

    Trackback by Sleeve Blog — June 29, 2016 @ 7:49 pm

  26. […] enemmän aikaiseksi nopeiden lihassolujen hypertrofiaa (Ogborn & Schoenfeld 2014 ja katso Schoenfeld blogi-kirjoitus). Joka tapauksessa, jos tavoitteena on kasvattaa lihasta, tulisi tämän ajattelumallin mukaan […]

    Pingback by Isoilla kuormilla kovimpaan kuntoon: Ethän pelkästään ”jumppaa”? – Forssell ja Hulmi | Lihastohtori — July 23, 2016 @ 1:12 am

  27. […] point, I will link some of the recent work of Brad Schoenfeld for you to look at below:   http://www.lookgreatnaked.com/blog/does-light-load-training-build-muscle-in-experienced-lifters/   – Set a stop watch for 30 seconds minimum to 5min max (you could do more than 5min but […]

    Pingback by Easy on Paper… | RossFit P.T — August 23, 2016 @ 7:23 am

  28. […] show that you can make muscle gains training in any rep range as long as you’re progressing (low load, medium load, and high load). But results are not equal in all situations. The medium rep ranges […]

    Pingback by Best Rep Range for Muscle Growth – How heavy should you train? – ThinkEatLift Stage — November 9, 2016 @ 6:14 pm

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.