Final answer:
During low-intensity activities, the ideal source of energy is lipids. Fatty acids are the main fuel source and can sustain these activities for a long time. Glycogen stores can also be used, but they may become depleted, leading to fatigue.
Step-by-step explanation:
During low-intensity activities, the body primarily relies on lipids as the ideal source of energy. Fatty acids are the main fuel source during prolonged, low-intensity activity. The body's fat reserves are almost unlimited, allowing these activities to continue for a long time. While a small amount of glucose from glycogen stores is also used, these stores can eventually be depleted, leading to fatigue.
For prolonged, low-intensity activity, lipids (fatty acids) are the ideal energy source due to their abundance in the body and the efficient ATP production via aerobic metabolism.
The ideal source of energy for prolonged, low-intensity activity is lipids (fatty acids). During such activities, the body primarily relies on aerobic metabolism, which is efficient and capable of producing a significant amount of ATP. Fat reserves in the body are abundant, allowing low-intensity exercises to be sustained for extended periods. While a small amount of glucose is also utilized, the body's glycogen stores can become depleted, leading to fatigue. Therefore, fatty acids serve as the predominant energy source for longer durations of low-intensity physical activity.