Question

Ryan is finishing his trail half marathon and starts to sprint the last half mile of the race. During this time Ryan’s legs really start to become sore. Describe, in detail, what is happening metabolically in his muscles during this last half mile. Elaborate on how this affects the rest of the metabolic pathways.

Answer 1

Q. what is happening metabolically in his muscles during this last half mile.

ANS ---

Measurements of metabolic changes, such as oxygen consumption, carbon dioxide exhalation or lactate concentration.

Ryan starts to sprint, on metabolism performance, 16 recreationally-active, untrained, men (V̇O2peak= 3.8±0.1 l.min−1) were randomly assigned to either a training (n= 8) or control group (n= 8). It is performed a 30-sec cycle sprint and a test to measure V̇O2peak before and after eight weeks of sprint. Muscle samples were obtained at rest and immediately following the pre and post training sprints and analysed for high energy phosphagens, glycogen and lactate; the activities of both phosphofructokinase (PFK) and citrate synthase (CS) were also measured and muscle fibre types were quantified resulted in a 7.1% increase in mean power output (p<0.05), an 8 % increase in V̇O2peak (p< 0.001), a 42% increase (p< 0.01) in CS activity and a 17% increase (p< 0.05) in resting intramuscular glycogen content. In contrast, neither PFK activity nor fiber type distribution changed with training. An increase (p< 0.05) in mean power output and attenuated (p< 0.01) ATP degradation were observed during sprint. Glycogen degradation during sprint exercise was unaffected by sprint training. These data demonstrate that sprint training may have enhanced muscle oxidative but not Glycoltic capacity. A significant reduction in ATP occurs during maximal dynamic exercise in humans. The marked metabolic changes caused by the treadmill sprint and its close simulation of free running makes it a valuable test for examining the factors that limit performance and the etiology of fatigue during brief maximal exercise.

Q.How this affects the rest of the metabolic pathways.

ANS --