Light vs Heavy Weight - Which is Better for Muscle Growth?
 

Researchers in the UK had trained men perform 4 sets of leg extensions using a weight htat limited them to about 4 reps per set and a weight that allowed them to complete about 25 reps per set. When the men did the 4 sets with light weight for higher reps, muscle protein synthesis (which leads to muscle growth) of the quadriceps was elevated by about 60% more than when they did the 4 rep sets. Hence, the verdict is that light weight for high reps wins for its ability to stimulate muscle protein synthesis and prevent injuries. However, you need to frequently change your weight and rep ranges to keep the muscles stimulated and build both strength and muscle mass. Alternate between reps as low as 3-7 and as high as 25-50 but with the majority of workouts in the 8-15 range for best results.