Mitochondrial oxygen affinity increases after sprint interval training and is related to the improvement in peak oxygen uptake, 2020, Larsen et al

Open access, https://onlinelibrary.wiley.com/doi/full/10.1111/apha.13463

 

Note that a lower p50mito means the mitochondria have greater oxygen affinity, which reflects excess respiration capacity.

Unless the participant has a severe disease, VO2Max is always limited by the vascular system, namely the amount of oxygen that can be delivered to the muscle. Mitochondrial capacity is normally in excess of this.

But this begs the question, what happens during exercise training, how is this mitochondrial capacity regulated and how is this related to oxygen affinity?

The study results suggest that mitochondrial respiratory capacity is well regulated and remains in excess of the VO2Peak capacity after sprint training. Although the correlation between change in p50mito and VO2Peak was only moderate (R^2=0.41).