Saturday, April 8, 2017
Dietary constituents with “exercise mimetic'' action
Abstract (as presented by the authors of the scientific work):
"Endurance exercise, when performed regularly as part of a training program, leads to increases in whole-body and skeletal muscle-specific oxidative capacity. At the cellular level, this adaptive response is manifested by an increased number of oxidative fibers (Type I and IIA myosin heavy chain), an increase in capillarity and an increase in mitochondrial biogenesis. The increase in mitochondrial biogenesis (increased volume and functional capacity) is fundamentally important as it leads to greater rates of oxidative phosphorylation and an improved capacity to utilize fatty acids during sub-maximal exercise. Given the importance of mitochondrial biogenesis for skeletal muscle performance, considerable attention has been given to understanding the molecular cues stimulated by endurance exercise that culminate in this adaptive response. In turn, this research has led to the identification of pharmaceutical compounds and small nutritional bioactive ingredients that appear able to amplify exercise-responsive signaling pathways in skeletal muscle. The aim of this review is to discuss these purported exercise mimetics and bioactive ingredients in the context of mitochondrial biogenesis in skeletal muscle. We will examine proposed modes of action, discuss evidence of application in skeletal muscle in vivo and finally comment on the feasibility of such approaches to support endurance-training applications in humans."
Covered topics (the letter size corresponds to the frequency of mentioning in the text):
Conclusions (as presented by the authors of the scientific work):
"Endurance exercise is a potent stimulus to induce mitochondrial biogenesis in skeletal muscle (Holloszy, 1967; Molé et al., 1971; Oscai and Holloszy, 1971; Hoppeler et al., 1973; Spina et al., 1996). The nutritional approaches described herein could provide a framework to support endurance training via enhancing mitochondrial biogenesis. In this context, we propose that these small molecules should be viewed as exercise enhancers, not mimetics, as they have minimal effect in basal conditions. In the future, it will be interesting to explore the efficacy of using these nutrients in human studies in vivo, to identify the exercise setting in which they may have the most benefit as well as developing optimal supplementation strategies. In this regard, future studies could examine the effect of bioactives during and in recovery from exercise across a variety of intensities, and also examine supplementation during periods of tapering or detraining to shed light on the practical implications of bioactives as regulators of mitochondrial biogenesis in skeletal muscle. In order to achieve this, researchers should perform randomized, placebo-controlled, intervention trials in human subjects (Hasler, 2002), and examine the extent to which the bioactive ingredient in question is absorbed and bioavailable in skeletal muscle (Crowe et al., 2013). Once achieved, it is hoped that bioactives such as those discussed, and derivatives/associated bioactive ingredients yet to be identified may lead to the next-generation of nutritional supplements to specifically enhance mitochondrial adaptations to endurance training."
Full-text access of the referenced scientific work:
Craig DM, Ashcroft SP, Belew MY, Stocks B, Currell K, Baar K, Philp A.
Utilizing small nutrient compounds as enhancers of exercise-induced mitochondrial
biogenesis. Front Physiol. 2015 Oct 27;6:296. doi: 10.3389/fphys.2015.00296.
eCollection 2015. Review. PubMed PMID: 26578969; PubMed Central PMCID:
Prof. Atanas G. Atanasov (Dr. habil., PhD)