Sarcoplasm, women & weights

So after yet another post on sarcoplasmic hypertrophy I think it is safe to declare September Sarcoplasmic Hypertrophy month, at least on this site. For those that have read my previous posts on the topic (are bodybuilders really weak and just glycogen), it’s probably apparent that I think that we’ve put the cart before the horse when we started declaring bodybuilders useless bags of sarcoplasm. The other thing that likely stood out was that, while many articles make it seem like this area is well fleshed out, there is pretty much ZERO in terms of any peer-reviewed research showing the existence of purely sarcoplasmic hypertrophy, especially not many sub-cellular comparisons of muscles of bodybuilders and powerlifters.

In the course of my research for those posts I stumbled across an article that, while lacking any invasive measures of sub-cellular muscle structure, nevertheless provided evidence to suggest that there may be fewer differences regarding muscle structure and strength between bodybuilders and powerlifters. At the very least, less of a difference than the many internet forum flame wars on the topie would lead us to believe.

Powerlifters are a little ‘curvier’ than bodybuilders

The study by Johnson et al (1) compared two groups of ten female bodybuilders and powerlifters using measures of body composition (hydrostatic weighing, skin folds) but also included measures of upper (elbow) and lower body (knee) strength and anaerobic performance. The female powerlifters came out on the ‘curvier’ end of the spectrum, having higher body-weights and skin folds, indicating a greater amount of fat mass. Despite the higher scale weight, the two groups had remarkably similar lean-body mass, and when it came down to performance, the groups were very similar. No significant differences were found between the groups for measures of strength of the upper and lower body (knee extension/flexion, elbow extension/flexion), and anaerobic performance (Wingate test) was similar as well.

Lean body mass, sarcoplasm and strength

But if the authors didn’t look at sub-cellular structure, how do we know that the bodybuilders weren’t all sarcoplasm while the powerlifters were all force-producing myofibrils? Certainly any type of measure of individual fibre areas and composition would lead to more conclusive results, however the simple strength and physical characteristics provided in the study really tell us what we need to know. As I mentioned above, both groups had the same lean-body mass, and while this includes tissues other than muscle (ligaments, tendons, bone, organs), in athletic populations it’s safe to assume that any differences are likely due to changes in muscle mass and not the other components. Now if the bodybuilders had elevated sarcoplasm within the muscle component of the lean-body mass measurement, they should be weaker than the powerlifters for an equivalent amount of muscle mass. But this didn’t happen. The data above shows that powerlifters and bodybuilders had similar strength levels for both the upper and lower body (knee and elbow only).

While this study doesn’t have the largest sample size or invasive measures of muscle hypertrophy and sub-cellular structure, maybe these simple physiological variables (lean-body mass and strength) tell us all we need to determine whether bodybuilders are just useless bags of sarcoplasm. The other possibility, one that can’t be addressed by this paper, is that maybe the findings here are specific to females and that males could have a different response. Either way it’s a citation that’s often missing when sarcoplasmic hypertrophy is discussed which is a shame considering it’s one that should definitely be considered.


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Dan Ogborn