An interesting paper, just published yesterday, found that load — the amount of weight — does not determine the degree of strength and muscle mass gains in weightlifting. “Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men”.(1)
We reported, using a unilateral resistance training (RT) model, that training with high or low loads (mass per repetition) resulted in similar muscle hypertrophy and strength improvements in RT-naïve subjects. Here we aimed to determine whether the same was true in men with previous RT experience using a whole-body RT program and whether post-exercise systemic hormone concentrations were related to changes in hypertrophy and strength. Forty-nine resistance-trained men (mean ± SEM, 23 ± 1 y) performed 12 wk of whole-body RT. Subjects were randomly allocated into a higher-repetition (HR) group who lifted loads of ~30-50% of their maximal strength (1RM) for 20-25 repetitions/set (n=24) or a lower-repetition (LR) group (~75-90% 1RM, 8-12 repetitions/set, n=25), with all sets being performed to volitional failure. Skeletal muscle biopsies, strength testing, DXA scans, and acute changes in systemic hormone concentrations were examined pre- and post-training. In response to RT, 1RM strength increased for all exercises in both groups (p < 0.01), with only the change in bench press being significantly different between groups (HR: 9 ± 1 vs. LR: 14 ±1 kg, p = 0.012). Fat- and bone-free (lean) body mass, type I and type II muscle fibre cross sectional area increased following training (p < 0.01) with no significant differences between groups. No significant correlations between the acute post-exercise rise in any purported anabolic hormone and the change in strength or hypertrophy were found. In congruence with our previous work, acute post-exercise systemic hormonal rises are not related to or in any way indicative of RT-mediated gains in muscle mass or strength. Our data show that in resistance-trained individuals load, when exercises are performed to volitional failure, does not dictate hypertrophy or, for the most part, strength gains.
In a previous study, it was found that low-load, high volume weight training actually stimulates muscle protein synthesis more than high-load, low volume work.(2)
Another study found that resistance load (weight) does not determine hypertrophy (muscle growth) in young men.(3)
Both of the previous studies relied on weightlifting newbies. This is often the case with such studies, since the pool of men who lift weights is much smaller, and it’s more difficult to recruit them not just because of small numbers, but because many of them don’t want to change their routines. Weightlifting novices also gain muscle and strength quickly, so scientists that study them can see results over the relatively short span of a project; weightlifting veterans slug it out for every pound of muscle gained.
The present study used men who were already resistance trained.
The key here is that all the lifts were done to failure, i.e. each set was performed until the subject could not do one more repetition of the move.
The previous study (reference no. 2) even suggested that low-load, high volume was even better for muscle anabolism; this however, referred to biochemical alterations in response to an acute bout of exercise, which doesn’t necessarily translate into gains over time.
Most of us who lift weights do so for bodybuilding: increased muscular size and strength. Powerlifters and Olympic-style always want to lift heavier weights.
We just want to look better, get in better shape, and gain strength and health.
It looks like we don’t always need to be pushing for the higher weight on each lift. Adding reps to the same lift and weight may be equally as or even more effective than more weight.
I’ll use myself as an example. I’m relatively weak in the squat; I can squat 175 pounds for six or seven reps. But I could squat 155 pounds for 20 reps.
A 20-rep squat set is a killer. Maybe the fact that my legs feel like rubber after a 20-rep set indicates that that’s what I need to be doing.
The temptation to reach for ever greater weight is always there. It gives us a sense of accomplishment, a way to measure progress, besides the gym show-off factor.
Ever greater weight also means a greater chance of injury. Lifting heavy weights always requires you to be completely on top of your game. Lighter weights with more reps can be done any time.
Heavy weights also put more stress on tendons and joints.
I don’t know that I’ll be completely revamping my workout routine in light of this, but I will be paying attention and going for more reps.
You often hear that big lifts like the squat and the deadlift are helpful because they result in greater rises in growth hormone and testosterone, and thus cause greater growth overall. Yet this is not the case, and the present study confirms this” “acute post-exercise systemic hormonal rises are not related to or in any way indicative of RT-mediated gains in muscle mass or strength”.