Nice study just came across. Looks like gains in strength and size can be similar, whether you lift light weights to failure, or heavy weights to failure.
“We have reported that the acute post-exercise increases in muscle protein synthesis rates, with differing nutritional support, are predictive of longer-term training-induced muscle hypertrophy. Here, we aimed to test whether the same was true with acute exercise-mediated changes in muscle protein synthesis. Eighteen men (21±1 yr, 22.6±2.1 kg∙m-2 means±SE) had their legs randomly assigned to two of three training conditions that differed in contraction intensity (% of maximal strength [1RM]) or contraction volume (1 or 3 sets of repetitions): 30%-3, 80%-1 and, 80%-3. Subjects trained each leg with their assigned regime for a period of 10wk, 3 times/wk. We made pre- and post-training measures of strength, muscle volume by magnetic resonance (MR) scans, as well as pre- and post-training biopsies of the vastus lateralis, and a single post-exercise (1h) biopsy following the first bout of exercise, to measure signalling proteins. Training-induced increases in MR-measured muscle volume were significant (P<0.01), with no difference between groups: 30%-3 = 6.8±1.8%, 80%-1 = 3.2±0.8%, and 80%-3= 7.2±1.9%, P=0.18. Isotonic maximal strength gains were not different between 80%-1 and 80%-3, but were greater than 30% -3 (P=0.04), whereas training-induced isometric strength gains were significant but not different between conditions (P =0.92). Biopsies taken 1h following the initial resistance exercise bout showed increased phosphorylation (P<0.05) of p70S6K only in the 80%-1 and 80%-3 conditions. There was no correlation between phosphorylation of any signalling protein and hypertrophy. In accordance with our previous acute measurements of muscle protein synthetic rates a lower load lifted to failure resulted in similar hypertrophy as a heavy load lifted to failure.”
Seems to me if this is true, there would be no reason to lift light little weights for high reps. It just takes too long! (unless you like sitting there, wasting your time…)
Since the point-of-failure (where you can’t possibly physically do one more rep) is where muscular growth is initiated, the best choice of action is to hit that failure point as quickly as possible, and just get it over with! Lift heavy. Lift for a handfull of reps. Make sure you hit failure!
I find it interesting when I see folks (mostly women) in the gym lifting puny little 5 pound weights, bicep curls or whatever. They sit there for minutes, repping these weights out, and not even going to failure, but just stopping short of tiredness (or boredom!).
They are wasting so much time.
They are not hitting failure, therefore progress is slowed.
They are more or less doing “cardio”, further hindering progress through hightened cortisol and overuse of the aerobic pathway. [Read my post on
the usefulness of cardio]
We need to stop looking at fitness from a man’s way vs. a woman’s way, and start looking at it from a practical standpoint. Men and women should not train that much differently. We all have the same goals, to lose fat, get shaped, and look good naked.
The fastest way to do that is to give up your stigma against heavy weight training, and just go for it. It’s the fastest way (with the proper diet, of course) to burn fat and shape your body the way you want. Muscle is the most metabolically expensive thing in your body, and is responsible for burning the most fat. It also provides a metabolic reserve, which keeps you resistant to disease and illness long into old age, and it keeps you from “bouncing back” to your previous body weight (see metabolic reserve). Plus it just looks good! Because let’s face it, Which would you rather have?