|In know one could argue that you may see different results for other body parts than legs which were the only muscle group trained in the study at hand.|
Accordingly, the results of a recent study from the Ohio University are highly interesting. The findings Jennifer R. Herman-Montemayor, Robert S. Hikida and Robert S. Staron present in their latest paper could after all explain why "classic" resistance training resistance outperformed their (super-)slow cousins in the majority of studies.
As the authors rightly point out, previous investigations have paid little attention to the role of satellite cells during exercise-induced adaptations in human muscle (Kadi. 2005). In untrained muscle, most satellite cells are in the non-proliferative, quiescent state in. As Herman-Montemayer point out, they can however be activated by various stimuli linked to exercise:
"Several studies have shown an increase in the satellite cell population following resistance training in young and old, male and female subjects. Although additional research is needed to fully understand the various factors which may influence satellite cell response, it is clear that exercise provides a sufficient stimulus for satellite cell activation, proliferation, and possibly incorporation" (Herman.Montemayer. 2015).The process of incorporating satellite cells into the muscle is, as I've pointed out in previous articles, highly relevant not just for the repair, but also for the growth of skeletal muscle, because the subsequent increase in the number of myonuclei and thus reduced domain sizes will allow for a reduction of the exercise induced increases in myostatin which is a key factor that limits the influx of protein into the muscle and will thus allow for increased muscle growth.
|Did you know that vitamin A figures in myogenesis? Learn more!|
- the SS group performed 6-10 repetitions maximum (6-10RM) for each set with 10 s concentric (con) and 4 s eccentric (ecc) contractions for each repetition, while
- the TS and TE group performed 6-10RM and 20-30RM, respectively, at “normal” speed (1-2 s/con and ecc contractions).
To determine the individual effects of the workouts, the scientists performed pre- and post-training muscle biopsies that were then analyzed for fiber cross-sectional area (CSA), fiber type, SC content, myonuclear number, and MND.
|Figure 1: Changes in muscle fiber size, domain size and myonuclear number (Herman.Montemayer. 2015).|
Compared to the strength endurance group, which did not see any increases in satellite cell activity, that's still a plus, though. Of greater practical relevance than the increase in satellite cell number is yet the myonuclear number which did not change in any group.
- Kadi, Fawzi, et al. "The behaviour of satellite cells in response to exercise: what have we learned from human studies?." Pflügers Archiv 451.2 (2005): 319-327.
- O'Connor, Roddy S., et al. "Last Word on Point: Counterpoint: Satellite cell addition is/is not obligatory for skeletal muscle hypertrophy." Journal of Applied Physiology 103.3 (2007): 1107-1107.