Final answer:
The energy expenditure for moderate intensity, moderate duration exercise varies by individual and activity but generally fits within the guidelines of 150 to 300 minutes per week of activity as suggested by the 2018 Physical Activity Guidelines.
Step-by-step explanation:
The energy expenditure of moderate intensity - moderate duration exercise varies depending on multiple factors including a person's weight, fitness level, and the specific activity being performed. According to the 2018 Physical Activity Guidelines, adults are recommended to engage in 150 to 300 minutes per week of moderate-intensity aerobic activity. Examples of such activities include brisk walking, water aerobics, or leisurely cycling.
For example, climbing stairs at a moderate intensity at a power output of 150 watts with an efficiency of 20% shows how energy from food is utilized during exercise. If we consider a 1470 kJ (350 kcal) cup of yogurt as an energy source for this activity, it would last a woman approximately 2.33 hours (or about 140 minutes) to burn off this energy. This example also highlights how easily one can consume more calories than they can burn off with reasonable exercise, which is why balancing diet and exercise is crucial.