Final answer:
Exercise increases the rate of cellular respiration, which is needed to meet the heightened energy demand by producing more ATP. Endurance and resistance training lead to different cellular adaptations to improve performance. Cellular respiration becomes more efficient with regular training, enhancing energy production.
Step-by-step explanation:
Exercise affects the rate of cellular respiration by increasing the demand for ATP, which in turn requires a rise in the production of energy via cellular respiration. Aerobic respiration is significantly more efficient than glycolysis, as it produces approximately 36 ATP molecules per glucose molecule compared to four ATPs from glycolysis. Nevertheless, aerobic respiration needs a continuous supply of oxygen, which is facilitated by increased breathing and heart rates during exercise, enhancing O₂ delivery to muscles.
Endurance training leads to cellular adaptations, such as an increase in mitochondrial density, which enhances aerobic respiration efficiency and oxygen utilization. In contrast, resistance training causes muscular adaptations primarily related to muscle strength and size. After intense muscle activity, the body must repay the oxygen debt incurred, which necessitates increased oxygen intake post-exercise to replenish ATP, convert lactic acid back to pyruvic acid, and restore muscle energy reserves.
Thus, when we exercise, our cells respond by ramping up the cellular respiration process to meet increased energy demands. This is why an athlete's body becomes more efficient at using oxygen and generating ATP over time with regular training.