Vegans and omnivores respond similarly to resistance training Original paper

According to previous research, plant-based proteins may be less anabolic than animal-based proteins. Compared to omnivores, will vegans gain less muscle from resistance training?

This 12-week trial enrolled 19 vegans and 19 omnivores who had all been following their respective diets for years. Both groups followed the same lower-body resistance-training program (two weekly sessions). In both groups, daily protein intake was adjusted to 1.6 grams per kilogram of body weight (1.6 g/kg, so about 0.73 g/lb) using soy or whey protein, depending on the group. Every four weeks, the participants completed a 24-hour dietary recall.

Before and after the study, the participants had DXA scans, biopsies of the quadriceps, and ultrasounds of the quadriceps. They also performed a 1RM (1 repetition maximum: the maximum weight one is able to move once when rested) on an incline leg-press machine.

Adherence (to both the dietary regimen and the exercise regimen) and volume load (the product of sets, reps, and load) were similar between groups, as were the (statistically significant) increases in 1RM, leg lean mass, muscle cross-sectional area, and muscle-fiber cross-sectional area.

No adverse events were reported.

In order for both groups to eat the same amount of protein, the vegans had to supplement with considerably more of it. Vegans do tend to eat less protein overall, and plant-based proteins are often lower in quality, as we saw in another study we reviewed. This makes protein supplements especially useful for vegans.