Should We Do Cardio or Weight Training First?

One of the most common questions asked is whether you should do your cardio workout or weight training workout first. If your goals are to lose fat, get fitter and build muscle then you do need to combine both cardio and weight training, but how do you plan your workout with both? There are good arguments for choosing either option.

Cardio First

If you perform cardio first you should be able to improve your fitness levels quicker, as you will be doing cardio on a “full tank”. Also, you will burn more fat as again, you will be working out harder than if you had just performed your weight training workout. Another benefit is that you will be fully warmed up so that you can go straight into your weight training workout.

However, the downside of doing cardio first is that you will tire your muscles and reduce your glycogen reserves, which means that you will be unable to perform an optimal weight training session. But is this really a problem?

If your main goal is to build huge muscles, or you have some very specific strength goals (such as improving athletic performance) then it does not really matter. You will still be benefiting from your weight training workout.

Weight Training First

If your main goal is to build larger muscles, then weight training may be best done first. You should still warm up, but just a few minutes of cardio and then one light warm-up set before your work is enough.

By doing weight training first you can better monitor your strength gains as you are starting each session fresh. For example if you set a goal to squat 20 kg more within a month, you can only really be sure to monitor your progress if you are working out on fresh legs each time. If you cycle for 45 minutes before squatting you are not going to be able to push to your max.

Cardio after weight training can be a good way to ensure that you are really using exercise to develop an energy deficit which is needed to lose weight. However, you will find it hard to push yourself to the max, so HIIT / sprint intervals will not really be possible. Your cardio workout will best be done as a steady rate workout.

How Do The Professionals Manage Their Workouts?

Professional athletes and bodybuilders split their workouts. Pro-bodybuilders often perform a morning cardio session to aid fat loss, and then after a rest and several meals, they perform a long weight training session. This means that they get the most out of each session.

Athletes also split their workouts with sessions specific skills training, strength training sessions and endurance (usually running) sessions.

Do Both?

Of course, there is always the other option – do both at the same time. A recent change in organized fitness is that many classes are now providing a combination of strength and cardio throughout the class. One of the fastest growing systems which use this method is the CrossFit method which will generally start with some cardio warm ups, then move to bodyweight exercises and then a series of weight training exercises, and then finally the “workout of the day” which often includes a sprint, bodyweight and lifting exercises in a circuit.

Other fitness classes such as the BodyPump class provide a low intensity, high volume form of weight training, where light weights are used throughout but many repetitions are performed. More traditional fitness classes. such as circuit training and military fitness training also often combine strength exercises and cardio.

Determine Your Goals

So, in short, if your goal is to have larger muscles and be stronger, then you should do your weight training first. If your goal is to lose more fat and be toned with smaller, leaner muscles, then do your cardio first.

If you wish to do both, then you really should consider splitting your workouts. Spend one day focussing on cardio and then the next on weight training. Or do as the pro-bodybuilders do and get your cardio done first thing in the morning and then weight training later in the day or the evening. This is obviously only possible if you have a lot of free time.

If you are planning to do a long cardio workout and also build muscle, then you do need to start thinking about nutrition more. After your long cardio sessions take a high GI carb snack to ensure that the drop in glycogen does not prompt a breakdown of muscle tissue. Also, get some extra protein after the weight training workouts.

Ultimately the most important consideration is that you need to do what you are most comfortable with. If you are getting the results you want then stick with it.

Word of caution: Over-training can become a big problem when you try to do a whole cardio workout and a weight training workout.

Some Research

Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises.
by Wilson JM. J Strength Cond Res. 2012 Aug;26(8):2293-307. doi: 10.1519/JSC.0b013e31823a3e2d.

Main findings: 

 resistance training concurrently with running, but not cycling, resulted in significant decrements in both hypertrophy and strength

The Effect of Concurrent Training by Len Kravitz. University of New Mexico website. Accessed 18th June 2013.

This research asked the following questions:

1. Does prior aerobic exercise compromise strength training, and if so, for how long?
2. Does the intensity of aerobic training have a varying affect on strength performance?
3. Is acute strength training affected depending on muscle groups used in aerobic exercise?

Main findings:

There was no difference in strength training performance when subjects performed high-intensity interval training (high-intensity intervals above 85% of maximum aerobic capacity) or submaximal continuous training (at 70% of maximum aerobic capacity).

Incline leg-press was dramatically influenced by the aerobic exercise.

Should the trainer wish to ensure no compromise of strength training output in a concurrent workout session, another educated option is to perform the resistance exercise first, followed by the aerobic training.