High-intensity activity engages more muscle fibers, which essentially doubles the metabolic boost of the exercise.
If you go out and walk or jog, doing some sort of low-intensity exercise for 30 minutes, the only muscle fibers working are the slow-twitch kind in your legs. Your fast-twitch muscles, basically half of the fibers, are just along for the ride.
They’re just as sedentary as they are when you’re sitting in a chair.
