Pi-based biochemical mechanism of endurance-training-induced improvement of running performance in humans.
Eur J Appl Physiol
; 2024 Sep 17.
Article
in En
| MEDLINE
| ID: mdl-39287637
ABSTRACT
PURPOSE:
Endurance training improves running performance in distances where oxidative phosphorylation (OXPHOS) is the main ATP source. Here, a dynamic computer model is used to assess possible biochemical mechanisms underlying this improvement.METHODS:
The dynamic computer model is based on the "Pi double-threshold" mechanism of muscle fatigue, according to which the additional ATP usage appears when (1) inorganic phosphate (Pi) exceeds a critical value (Picrit); (2) exercise is terminated because of fatigue, when Pi reaches a peak value (Pipeak); (3) the Pi increase and additional ATP usage increase mutually stimulate each other.RESULTS:
The endurance-training-induced increase in oxidative phosphorylation (OXPHOS) activity attenuates the reaching of Pipeak by Pi (and thus of V Ë O2max by V Ë O2) at increased power output. This in turn allows a greater work intensity, and thus higher speed, to be achieved before exercise is terminated because of fatigue at the end of the 1500 m run. Thus, identical total work is performed in a shorter time. Probably, endurance training also lowers Pipeak, which improves the homeostasis of "bioenergetic" muscle metabolites ADP, PCr, Pi and H+ ions.CONCLUSIONS:
The present dynamic computer model generates clear predictions of metabolic changes that limit performance during 1500 m running. It contributes to our mechanistic understanding of training-induced improvement in running performance and stimulates further physiological experimental studies.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Eur J Appl Physiol
Journal subject:
FISIOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Poland
Country of publication:
Germany