What It Actually Means to 'Tone' Your Muscles
What happens when you work a muscle? When you ask your muscles to do something, they get better at doing it. Now, the human body is complex, so of course there arentonlytwo things that happen. But those are the main ones. You burn calories and build endurance with cardio, too, such as running. These last two items do not have a visible effect on your body. You cant tell how good somebodys endurance is by looking at them....