High Reps vs. Heavy Weights: Which Is Better For Muscle Growth?
High Reps vs. Heavy Weights: Which Is Better For Muscle Growth?

I think this was in MMI.I can't remember.Don't quote me.Great read though.

“Everyone wants to be a bodybuilder, but no one wants to lift heavy-ass weights!”
Ronnie Coleman



Muscle growth is a complex process; professional bodybuilders are divided into two camps: the light weight, high-rep camp and the heavy weight. In order for a muscle to grow, muscle overload must occur with resistance exercise; no argument there, however several books have advocated high-rep exercises to stimulate muscle growth. The best example, the 50-rep squats to blast leg muscle, is a commonly used method. The most famous bodybuilder advocating high reps for muscle growth was Tom Platz; he was famous for sets with reps of 20 to 30 in the squat. A small reminder, Platz was known to squat 500 pounds for over 30 reps!!! Proponents of the high-rep training claim that high reps increase blood flow, which enhance nutrient delivery, cause massive increases in nitric oxide and greater muscle pumps, which stimulate muscle growth.



Vascular Occlusion With Light Weight Produces Muscle Hypertrophy

It was previously thought that only performing resistance exercise at a load greater than 65 percent was enough to stimulate muscle growth. However, some recent studies have reported that muscle tension is not the only way to produce muscular hypertrophy. For instance, a low-intensity (~50 percent 1 RM) resistance training performed with leg extensions caused a marked increase in muscular size [~12 percent gain in muscle size and strength (~20 percent gain) when combined with moderate vascular occlusion.8 The effects of these exercise training regimens with restricted muscular blood flow are likely mediated by the following processes: 1) stimulated secretion of growth hormone by intramuscular accumulation of metabolic byproducts, such as lactic acid10; 2) moderate production of free radicals and tissue damage promoting tissue growth9; and 3) additional recruitment of fast-twitch fibers in a hypoxic (low oxygen) condition.11 These studies suggest that the muscle mass-building effects of resistance exercise involves not only muscle tension (weight) but also metabolic, hormonal and neuronal factors. Higher repetition exercises has been shown to increase testosterone, growth hormone (GH) and insulin-like growth factor 1 (IGF-1).1,2,3,4 You will definitely feel a greater muscle burn with a lighter weight and feel more pumped, but does a light weight, high-rep program such as the 50-rep squat routine lead to greater muscle growth?


Light Weight Exercise vs. Heavy Weights: Which Is Better?

Researchers tested a light-weight protocol and a heavy resistance exercise program to determine if light weight programs with lots of reps can stimulate muscle growth. Researchers took 12 healthy young men and made them perform 12 weeks of resistance exercise on a leg extension machine; they performed three workout sessions per week. A total of 10 sets was assigned to two groups:

A.) One leg with light weight; 36 repetitions per set (15 percent of 1 RM)

B.) The other leg with heavy weight; 8 repetitions per set (70 percent of 1 RM)

Here is what’s really interesting; even though they performed different rep ranges, both groups performed the same workout volume. The good thing about this study is that the subjects served as their own controls, so they were not being compared to other people.