Which activity is considered the most aerobically demanding in terms of calories burned per hour?

Cross-country skiing is regarded as the most aerobically demanding activity in terms of calories burned per hour for several reasons. This type of skiing engages multiple major muscle groups, including the arms, legs, and core, which leads to a higher overall energy expenditure compared to many other forms of exercise. The continuous movement against resistance—whether from the snow or the terrain—also adds to the aerobic demand significantly.

Moreover, cross-country skiing often involves varying levels of intensity and can be sustained over long periods, enhancing cardiovascular fitness and calorie burning even further. The combination of endurance, strength, and coordination required in this activity contributes to its high calorie-burning potential.

Other activities like running a marathon, cycling, and swimming are also effective for burning calories, but they do not engage as many muscle groups simultaneously or provide as much resistance as cross-country skiing does. Therefore, while they are great forms of aerobic exercise, they typically result in a lower total calorie burn when compared to cross-country skiing at a similar exertion level.