Health aNd Fitness Guide

This is the ninth post in a series of Workout and Nutrition Tips by Jason Gremley.

I am frequently asked which should be first when doing cardio and weight training exercise in the same workout session.

A brief warm-up on cardio equipment (for example, a treadmill or stairclimber) is generally a good idea before starting a weight training session. However, there are good reasons for working out with weights before any long or intensive cardio exercise, regardless of whether you are focusing on gaining muscle or losing bodyfat.

Your body’s preferred energy source for weight training is glycogen (carbohydrates stored in your muscles and liver). If you do a lot of cardio first, there will be no glycogen left to fuel your weight training workout. Your body will then use bodyfat and possibly even some muscle tissue for energy when hitting the weights after a lot of cardio. That is highly inefficient at best and counterproductive if any muscle tissue gets used. For making muscle gains, do your cardio after a weight workout or at an entirely different time altogether.

If you use up your glycogen supplies by weight training first, then your cardio session afterwards will burn a lot more bodyfat then if you did the cardio first. Unlike with weight training, your body “likes” to fuel aerobic exercise with bodyfat. But it will do so only after glycogen stores have been reduced. Thus, putting intense cardio sessions after you train with weights will maximize your fat burning.