Cardio or Strength First? An Expert Gives a Professional Opinion

Order matters when it comes to sequencing your workout.

If you’re performing both strength training and cardio in a single workout, you need to decide which one to do first. Which option gives you better results? Whether to go cardio-before-strength or strength-before-cardio is the subject of much debate, but here’s my professional opinion: do a light warm-up followed by strength, and then cardio.

There are both metabolic and practical reasons for sequencing strength training before cardio. To understand the metabolic argument, we need to look at how the body uses energy. When you eat food, your body breaks down carbohydrates into glucose, and then stores the glucose in your liver and muscles as glycogen.

Glycogen is your body’s go-to energy source when you work out, but your body is incredibly adaptable and will also consume fat and protein. The intensity and duration of an activity determines what percentage of the energy burned comes from fat, protein or glycogen.

Doing cardio before weightlifting is a good way to burn through most of your glycogen stores, leaving you with less energy to power through a strength training session. Much of new muscle growth is stimulated by the last hard-to-finish reps in a weightlifting set, so if you don’t have the energy to finish strong, your results will likely suffer. Cardio generally relies less on bursts of energy than weightlifting and can therefore be performed more efficiently on slow-burning energy from fat.

The practical reason for performing strength training first is much more straightforward. Strength training requires that you maintain proper lifting form during intense work, which is much easier when you’re not already fatigued.

If you start out strength training feeling fresh and full of energy at the beginning of your workout, you will likely be able to push yourself harder and lift more weight.

The more intense your exercise, the more the order in which it’s performed matters. If you’re a true fitness beginner, do whatever feels best for you and will make you want to hit the gym. Getting into a fitness routine is more important at this point than fine-tuning the efficiency of your workouts. For more experienced exercisers, performing strength training followed by cardio, or doing each on separate days entirely, is the best way to go.