Aerobic exercise makes your heart and other muscles use oxygen more efficiently.

But the pain made our backs numb and we didn't know which muscles to use to help us get up again.

In an instant grow wings and the specialized muscles to use them?

This also corresponds with the time that muscles use up their stored glycogen.

If you've got bigger muscles and the will to use them, the others have to go along with you.

The emphasis is on mastering skills and learning which muscles to use to achieve the best form and the most power.

Your muscles use the glucose, and regular exercise takes care of that.

And the result is that muscle uses far more calories than the same weight of fat.

It feels like work to you, because muscles use energy just to maintain tension, but the work is not being done on the weight.

The overall result is that insects' bodies can deliver much more oxygen to their muscles, and the muscles use every bit of it.