A Unified Theory of Bioenergetic Demands In Sport

In a previous article, titled The Paradigm Shift In Bioenergetics, I outlined a contemporary model of bioenergetics. The key takeaways from that article are as follows:

1. The support of muscle contraction requires rapid non-oxidative ATP production on the millisecond time scale and within 0–15 milliseconds of muscle contraction phosphocreatine is broken down to restore ATP.

2. In order to sustain muscle contractions we need a non-oxidative energy supply. However, we run into an issue given that glycolytic intermediates like glucose within a muscle are limited.

3. Biochemical evidence shows that glycogen phosphorylase can rapidly increase its activity, and as a result glycogen can be broken down to restore the phosphocreatine needed to sustain contractions.

4. Between contractions the ATP needed to re-synthesize glycogen, phosphocreatine, and re-establish ion gradients comes from the oxidation of lactate. However, only a fraction of the lactate produced needs to be oxidized to restore these energy …