|Working out ain't child's play, right? "Go Heavy or Go Home!" this is the mantra of true champions, but is it also the mantra of skeptical scientists?|
The data the Russian researchers offer is acute, not chronic. It's not based on muscle size measurements, but on the measurement of anabolic signalling proteins and the expression of MyoD, IGF-1, myostatin & co. We know that all of them are involved in the process of skeletal muscle hypertrophy, but even if all of them are elevated, this is not identical to muscle size increases as you would measure them in a long(er)-term study.
I hope that the previous elaborations were detailed and convincing enough to increase your awareness of the limitation of the data I am about to cite.
|Figure 1: Toque and angle during knee extensions in the high intensity (HI), medium intensity (MI) and medium intensity continuous tension trial (MIR) - the subjects did bilateral leg extensions (Popov. 2014)|
"High intensity" vs. HIGH intensity: I am pretty sure most of you read my articles closely, for the rest it's important to note that the high intensity group trained at ~74% of the 1-RM - that's about 10 Reps to failure and actually not as heavy as some people may expect, when they hear "high intensity". Just remember one thing: Heavy ≠ intense - I see guys at my gym training with maximal weights and minimal intensity.
|Figure 2: Changes in p21, MyoD, myostatin and MGF in response to each of the three training regimen (Popov. 2014)|
Over the course of the 24 study period, however, the high intensity trial yielded distinctively more pronounced anabolic effects.
A more pronounced and sustained elevation in p21, a maximal increase in MyoD, a marker of satellite cell (muscle precursor cell) activity, a significantly more pronounced increase in the intramuscular isform of IGF, i.e. MGF (learn more) and, last but not least, a sustained reduction of the muscle growth break myostatin.
- Popov, Daniil V., et al. "The Influence of Resistance Exercise Intensity and Metabolic Stress on Anabolic Signaling and the Expression of Myogenic Genes in Skeletal Muscle." Muscle & nerve (2014).