Doing moderate, steady exercise like brisk walking or cycling for several weeks might boost the energy powerhouses in your leg muscles, which could help your body burn fuel better and improve overall...

Doing moderate, steady exercise doesn’t seem to change key muscle genes linked to making new mitochondria — the cell’s power plants — so the benefits might come from making existing ones bigger or merging them, not creating new ones.

Doing steady, moderate exercise regularly might help your muscle cells' energy factories work better by boosting a protein that helps them merge and stay healthy.

For people who aren't super fit to start with, different types of workouts—like steady cardio, intense interval training, and short sprints—boost the energy powerhouses in their muscles by about the same amount, around 23–27%.

When young guys who already work out do a lot of high-rep weight training for a short time, their muscles get bigger but their energy-producing parts actually become less dense, meaning bigger muscles don’t always mean more energy factories inside them.

Doing light, steady exercise—like a brisk walk—can boost the energy powerhouses in your muscles.