Marathon is a sport. His exercise intensity is too strong for ordinary people, and marathon runners must undergo professional training to bear it. For fitness enthusiasts, it is still necessary to find the right amount of exercise.

Marathon is a sport. His exercise intensity is too strong for ordinary people, and marathon runners must undergo professional training to bear it. For fitness enthusiasts, it is still necessary to find the right amount of exercise.

Marathon is a sport. His exercise intensity is too strong for ordinary people, and marathon runners must undergo professional training to bear it. For fitness enthusiasts, it is still necessary to find the right amount of exercise. Marathon is a sport. His exercise intensity is too strong for ordinary people, and marathon runners must undergo professional training to bear it. For fitness enthusiasts, it is still necessary to find the right amount of exercise. Marathon is a sport. His exercise intensity is too strong for ordinary people, and marathon runners must undergo professional training to bear it. For fitness enthusiasts, it is still necessary to find the right amount of exercise. Marathon is a sport. His exercise intensity is too strong for ordinary people, and marathon runners must undergo professional training to bear it. For fitness enthusiasts, it is still necessary to find the right amount of exercise. Marathon is a sport. His exercise intensity is too strong for ordinary people, and marathon runners must undergo professional training to bear it. For fitness enthusiasts, it is still necessary to find the right amount of exercise.