Exercise prescription and mitochondrial content and function

D.J. Bishop, The Institute of Sport, Exercise, and Active Living (ISEAL), Victoria University, Melbourne, VIC 8001, Australia.

While there is agreement that exercise is a powerful stimulus to increase both mitochondrial function and content, we do not know the optimal training stimulus to maximise improvements in mitochondrial biogenesis. This presentation will focus predominantly on the effects of exercise on mitochondrial function and content, as there is a greater volume of published research on these adaptations and stronger conclusions can be made. The results of cross-sectional studies, as well as training studies involving rats and humans, suggest that training intensity may be an important determinant of improvements in mitochondrial function (as determined by mitochondrial respiration), but not mitochondrial content (as assessed by citrate synthase activity) (Bishop, Granata, & Eynon, 2014; Granata et al., 2016a). In contrast, it appears that training volume, rather than training intensity, may be an important determinant of exercise-induced improvements in mitochondrial content (Granata et al., 2016b). Our recent results also indicate that the early molecular events in response to a single bout of exercise differ between high-intensity and high-volume exercise, and this may help to explain the different training responses (Granata et al., 2017).

Bishop DJ, Granata C & Eynon N. (2014). Can we optimise the exercise training prescription to maximise improvements in mitochondria function and content? Biochim Biophys Acta 1840: 1266-1275.

Granata C, Oliveira RSF, Little JP, Renner K, Bishop DJ. (2016a). Training intensity modulates changes in PGC-1α and p53 protein content and mitochondrial respiration, but not markers of mitochondrial content in human skeletal muscle. FASEB J 30: 959-970.

Granata C, Oliveira RSF, Little JP, Renner K, Bishop DJ. (2016b). Mitochondrial adaptations to high-volume exercise training are rapidly reversed following a reduction in training volume in human skeletal muscle. FASEB J 30: 3413-3423.

Granata C, Oliveira RSF, Little JP, Renner K, Bishop DJ. (2017). Exercise-induced modulation of PGC-1α and p53 in enriched subcellular fractions of human skeletal muscle. Sci Rep 7: 44227.