Posted on May 24, 2012, 6 a.m.
Lifting less weight more times is just as effective at building muscle as training with heavy weights.
Whereas convention submits that training with heavy weights—which can be lifted only six to 12 times before fatigue—is the best avenue to muscle growth, McMaster University (Canada) researchers submit data suggesting otherwise. Cam Mitchell and colleagues completed a series of experiments were conducted on healthy, young male volunteers to measure how their leg muscles reacted to different forms of resistance training over a period of 10 weeks. The researchers first determined the maximum weight each subject could lift one time in a knee extension. Each subject was assigned to a different training program for each leg. In all, three different programs were used in combinations that required the volunteers to complete sets of as many repetitions as possible with their assigned loads – typically eight to 12 times per set at the heaviest weights and 25-30 times at the lowest weights. The three programs used in the combinations were: one set at 80% of the maximum load; three sets at 80% of the maximum; three sets at 30% of the maximum. After 10 weeks of training, three times per week, the heavy and light groups that lifted three sets saw significant gains in muscle volume—as measured by MRI—with no difference among the groups. Still, the group that used heavier weights for three sets developed a bit more strength. The group that trained for a single set showed approximately half the increase in muscle size seen in both the heavy and light groups. The lead author commented that: “"We found that loads that were quite heavy and comparatively light were equally effective at inducing muscle growth and promoting strength," submitting that the key to muscle gain, is working to the point of fatigue.
Cameron J. Mitchell, Tyler A. Churchward-Venne, Daniel D.W. West, Nicholas A. Burd, Leigh Breen, Steven K. Baker, Stuart M. Phillips. “Resistance exercise load does not determine training-mediated hypertrophic gains in young men.” J Appl Physiol., April 19, 2012.