How can I improve my Metabolism?

Train with your heart rate at 65-75 per cent of your maximum heart rate. At this intensity level, you activate your fat
metabolism optimally as the rate of metabolism to available energy is at its largest. If you run faster, you’ll burn more fat,
but you’ll deplete the limited glycogen supply in your body. When your carbohydrate metabolism increases, fat
metabolism decreases. If the workload continues to rise, the muscles rev up and reach the anaerobic threshold.
Carbohydrates are the only fuel available. This is the point at which recreational athletes usually tire.

Can I speed up my muscle definition?

Here’s a turbo trick: go short and sweet twice a day
instead of one long workout. Ideally, try a compact workout
after getting up and another before bed. Speeding up your
metabolism twice burns more energy. Switch between
strength and cardio workouts and divide the workouts
according to muscle group. If you add one pure cardio day
per week and one day of rest, you’ll see results in no time.