Do You Need to Lift Heavy to Gain Muscle?

olympic lifting

Training advice can be quite bland. Ever looked at the “routines” which pro physique athletes post for hypertrophy in Muscle & Fitness or other similar industry garbage? You could be led to believe they’re all on the exact same program. Even the official position stand of the American College of Sports Medicine for hypertrophy is to perform sets at an intensity of 70-80% max strength (1 rep max/1RM) for 8-12 reps (ACSM, 2009).

Hence, you’ll see whole routines with a set/rep prescription of “4×8” or “3×12” – the question is, do you need to be in this range to maximise dem gainz?

Perhaps not.

Stimulating Hypertrophy

In my previous post on optimising protein intake for size and strength, we had a brief primer on resistance training and muscle protein synthesis, which I won’t repeat in detail here. In a nutshell, the effects of resistance training and protein intake are additive – both stimulate muscle protein synthesis, and the effect is greater with the combination than from either alone (Burd et al., 2011).

Hypertrophy, or muscle growth, is a process by which new proteins are synthesised and incorporated into muscle tissue. For this to happen, there needs to be a prolonged period of muscle protein synthesis over the long-term i.e. the stimulus of resistance training together with the maintenance of amino acid availability and energy surplus over the course of a hypertrophy phase. And for the record, you can’t build muscle while in calorie deficit.

The relevance of this is that measuring acute responses in muscle protein synthesis gives us a good indication of long-term outcomes in hypertrophy (Burd et al., 2012). So, back to the original question we’re answering in this post – do you need to be lifting at 70%, 80% or anything over 70% for a specific amount of reps in order to gain muscle? Let’s answer this by reference to a cool study:

Burd, N., West, D., Staples, A., Atherton, P., Baker, J., Moore, D., Holwerda, A., Parise, G., Rennie, M., Baker, S. and Phillips, S. (2010). Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men. PLoS ONE, 5(8), p.e12033.

What Was Studied?

The genesis for the question behind the study is the “size principle”; muscle fibres are recruited in progressive order from smallest to largest. Higher intensity (intensity being defined as % of 1RM) loads recruit the larger, more powerful muscle fibres quickly in order to generate enough force to move the weight. Lower loads tend not to activate larger muscle fibres, which aren’t required for lower intensity work and thus lower loads are associated with a muscular endurance rather than strength effect.

The standard school of thought is that contractions at a higher intensity elicit a maximal MPS response. The authors hypothesised that what mattered wasn’t the intensity threshold, but the maximal recruitment of muscle fibres. They conceived this could be achieved through different intensities, once the total volume of contractions allowed for recruitment of all fibres in a muscle.

They compared 3 groups of recreational exercises (average age 21) – one group lifted at 90% 1RM until failure (90FAIL), the second at 30% 1RM to failure (30FAIL), and the third group at 30% with their total work (reps x sets) matched to the 90%FAIL group.

What Did They Find?

Both the 90%FAIL and 30%FAIL groups elevated MPS by 301% and 279%, respectively, at 4-hours post-training. What was really interesting, however, is that MPS was elevated at 24-hours post training only in the 30%FAIL group.

Another interesting feature was that multiple anabolic signalling pathways were stimulated, and displayed different responses to the load stimuli. For example, the elevation of 4E-BP1, an mTORC1 anabolic signalling protein, at 4-hours post-training was greatest in the 30%FAIL only, but at 24-hours remained elevated only in thee 90%FAIL group.

Ultimately, this isn’t something to head scratch over: all roads lead to the same place. The take home message is that, as the authors expected, going to failure requires maximal recruitment of muscle fibres, which in turn will maximally stimulate MPS. The load is a limiting factor in how much work can be performed until failure, but the principle is the effort to failure, independent of the load.

What Does This Mean?

It means that load is irrelevant once you are recruiting all fibres in a muscle, which can be achieved by going to volition failure at lower intensities. When you match work – i.e. 3 sets of 8 at 30% vs. 3 sets of 8 at 80%, then the higher intensity will result in a greater MPS response because the muscular contractions at that intensity have recruited more muscle fibres.

But when you maximally recruit muscle fibres in line with the size principle, for smallest to largest until volitional failure, then the effect on MPS is the same whether you’re at a low intensity like 30% or a high intensity like 90%.

Let’s look at this graph from the same researchers (different paper) to illustrate the point:

Fig. 1. The relationship between intensity and MPS, and muscle fibre recruitment. (Burd et al., 2012)
So the bold line is work-matched, where there is a threshold of around 60% 1RM to stimulate MPS. But the doted line represents the fact that, as muscle fibres are recruited from smallest to largest, performing work to failure lowers the required intensity to 30% because maximal muscle fibre recruitment is still achieved.

Is This Credible?

Yep. It’s been consistently repeated. The same research team found MPS elevated 24-hours post-workout in both 90%FAIL and 30%FAIL groups in another study looking at the effect of protein intake on MPS without training or with training (Burd et al., 2011). This study confirmed the additive effect of protein feeding on resistance training induced MPS (Ibid.).

In a study using resistance-trained males, groups performing either 3 sets of 25-35 reps or 3 sets of 8-12 reps both experienced similar hypertrophy over an 8-week period (Schonfeld et al., 2015).

Another study compared three groups: one training 80% 1RM to failure 3 times per week for two weeks, another training 30% 1RM to failure 3 times per week for two weeks, and a third that switched between 80% and 30% every two weeks (Fink et al., 2016). Both the 30% and 80% groups had relatively similar muscle gains, while the group switching had suboptimal results (Ibid.)

In fact, there is a nice quote in this paper, which sums up the point of this article:

…muscle hypertrophy seems to be independent from the training load as long as effort is the same. (Fink et al., 2016)

The central concept is that achieving maximal fibre activation is the critical factor to elicit a sustained (>24hr) MPS response. This is supported by this line of research showing similar hypertrophy from different load intensities, where sets are taken to failure (Ibid.).

MPS is not, however, independent of volume. Comparing a group performing 1 set to failure at 70% against a group performing 3 sets to failure at 70%, the 3 set group had greater MPS responses (Burd et al., 2010). In another study, groups performing either 80% for 3 sets or 30% for 3 sets both had similar muscle gains that were greater than a group performing 80% for 1 set (Mitchell et al., 2012).

Meta-analysis of studies examining single sets vs multiple sets for muscle hypertrophy found 3 sets to be superior to a single set, with the effect plateauing around the 4-6 set mark (Kreiger, 2010). Thus, there is a continuum and a minimum effective dose in relation to volume for hypertrophy. 1 set is suboptimal, and the range of 3-5 appears to be the minimum effective dose (Kreiger, 2010; Burd et al., 2010; Mitchell et al., 2012).

It should be noted, however, that only groups training at higher intensities increase strength (Schonfeld et al., 2015; Fink et al., 2016). And not enough emphasis is placed on developing strength, in my opinion.

How Do I Put This to Use for #Gainzz?

I put two z’s in gainzz, that’s how badass this information could make your next hypertrophy phase.

First up, let’s address the idea that you have to train exclusively in a particular rep range, or that higher reps and lower reps can’t coexist in a program, by reference to this quote from a paper again showing no difference between loading intensities for hypertrophy:

…lifting heavier and lighter loads should not be mutually exclusive in terms of promoting RT adaptations, but as training “zones” that could easily be used in RT programs without the expectation that strength or muscle mass gains would be significantly compromised… (Morton et al., 2016).

So, let’s wrap up and provide some action points:

1: Lighter reps can be used to maximally stimulate MPS and gain muscle.

2: You can use any load you like, keep the effort high. Train with intensity regardless of the percentage intensity!

3: More sets are better – seems the 3-5 range is the minimum effect dose, with no need to go over 6.

4: This can be a great tool for hypertrophy even if your main lifts are strength orientated.

4: Use it on days you feel beat up or just don’t feel like smashing any records. You can still get a maximal training effect. Pick up some light weights and do 3 sets to failure.

5: Use the lighter loads to go to failure over heavier loads to stop your nervous system frying.

7: Play around with it and have fun. Forget traditional sets/reps and use a scheme that orientates toward high effort – try some rest-pause sets or DoggCrapp Training methods.

As an side, I think this also has massive application in older populations as a means of maintaining musculoskeletal integrity, preserving bone health, and preventing sarcopenia. I’ll post on this issue specifically soon.

What I love is that it crystallises things. Forget “optimal sets and reps” – focus on multiple sets at a really high effort.


American College of Sports Medicine. Progression models in resistance training for healthy adults. Med Sci Sports Exerc. 2009;41(3):687-708.

Burd, N., Holwerda, A., Selby, K., West, D., Staples, A., Cain, N., Cashaback, J., Potvin, J., Baker, S. and Phillips, S. (2010). Resistance exercise volume affects myofibrillar protein synthesis and anabolic signalling molecule phosphorylation in young men. The Journal of Physiology, 588(16), pp.3119-3130.

Burd, N., Mitchell, C., Churchward-Venne, T. and Phillips, S. (2012). Bigger weights may not beget bigger muscles: evidence from acute muscle protein synthetic responses after resistance exercise. Appl. Physiol. Nutr. Metab., 37(3), pp.551-554.

Burd, N., West, D., Moore, D., Atherton, P., Staples, A., Prior, T., Tang, J., Rennie, M., Baker, S. and Phillips, S. (2011). Enhanced Amino Acid Sensitivity of Myofibrillar Protein Synthesis Persists for up to 24 h after Resistance Exercise in Young Men. Journal of Nutrition, 141(4), pp.568-573.

Burd, N., West, D., Staples, A., Atherton, P., Baker, J., Moore, D., Holwerda, A., Parise, G., Rennie, M., Baker, S. and Phillips, S. (2010). Low-Load High Volume Resistance Exercise Stimulates Muscle Protein Synthesis More Than High-Load Low Volume Resistance Exercise in Young Men. PLoS ONE, 5(8), p.e12033.

Fink, J., Kikuchi, N., Yoshida, S., Terada, K. and Nakazato, K. (2016). Impact of high versus low fixed loads and non-linear training loads on muscle hypertrophy, strength and force development. SpringerPlus, 5(1).

Krieger, J. (2010). Single vs. Multiple Sets of Resistance Exercise for Muscle Hypertrophy: A Meta-Analysis. Journal of Strength and Conditioning Research, 24(4), pp.1150-1159.

Mitchell, C., Churchward-Venne, T., West, D., Burd, N., Breen, L., Baker, S. and Phillips, S. (2012). Resistance exercise load does not determine training-mediated hypertrophic gains in young men. Journal of Applied Physiology, 113(1), pp.71-77.

Morton, R., Oikawa, S., Wavell, C., Mazara, N., McGlory, C., Quadrilatero, J., Baechler, B., Baker, S. and Phillips, S. (2016). Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men. Journal of Applied Physiology, 121(1), pp.129-138.

Schoenfeld, B., Peterson, M., Ogborn, D., Contreras, B. and Sonmez, G. (2015). Effects of Low- vs. High-Load Resistance Training on Muscle Strength and Hypertrophy in Well-Trained Men. Journal of Strength and Conditioning Research, 29(10), pp.2954-2963.