Workouts: Should You Lift or Do Cardio First?

I get it: we’re all insanely busy and it’s a miracle that we can get to the gym at all. So when we work out, most of us try to get in both strength training and cardio exercise in a single session.

But should you do weights or cardio first?

If you’re looking to get stronger, lose body fat, and save time in the gym, the science says it’s best to lift weights before doing cardio. For why, read on.

1. Weightlifting first helps build muscle strength & size.

Getting stronger and building muscle requires progressive resistance (in which resistance is progressively increased as strength improves to facilitate muscle adaptation). That means you want to lift the most weight possible every workout. But when you do cardio before strength training you fatigue your muscles, which causes a decrease in the contractual force your muscles are able to produce, which means you can’t lift as much.

This is due to the ‘all or none principle’ of muscle contraction. Muscle fibers contract at 100%, or they don’t contract at all. So to lift something 70% of your max would require 70% of your muscle fibers to fire at 100%, rather than 100% of your muscle fibers to fire at 70%. Because of this, if muscle fibers are already fatigued from previous cardio, then less muscle fibers are available to contract for weight training.

In a study from the Journal of Strength and Conditioning Research, researchers found that subjects who did a bout of treadmill running before lifting weights had a decrease in muscle power and performed fewer reps compared to when they lifted before running on the treadmill. Plus, when subjects ran before lifting, lifting just felt heavier – the rate of perceived effort increased.

What’s more, cardio actually reduces your short-term sensitivity to insulin – the hormone responsible for transporting amino acids from your blood stream into your muscle cells for protein synthesis. That means doing cardio first limits muscle growth.

2. Lifting first optimizes fat burning.

Weight training relies on the glycogen stored in your muscles to fuel your workouts. Your working muscles will clear out any sugar floating around in your blood stream which prepares your body to turn to stored fat as a fuel source early in your cardio session.

Plus, while resistance training isn’t necessarily great at burning fat, it is good at mobilizing fat (releasing stored fat from your fat cells) because it increases levels of the hormone noradrenaline – fat that can be burned off later on the treadmill or stairclimber.

Knocking out your cardio after you crush the weights will burn more fat!

3. Cardio first increases risk of injury.

Especially for beginners, there’s always an increased risk of injury if you lift weights while exhausted. Proper form is more likely to suffer when you’re tired and it only takes a little slip up to cause an injury that can keep you out of the gym for weeks or months. Cardio injuries, on the other hand, tend to come from overuse and sustained impacts.

The Bottom Line

Sure, whatever you do last in your workout is going to suffer, but simply put, weight training doesn’t hurt cardio as much as cardio hurts weight training.

Plus, it saves time: cardio fatigues your muscles so when you finally get to lifting, you may find yourself having to take longer rests between sets to complete your reps, lengthening the duration of your workout.

The exception to the rule: If you’re training for an endurance event, do cardio and weight training on different days. If you’re training for a 5K, a marathon, a mud run, etc. your goal is to maximize performance in that event, so you want to go as hard as you can when you train. Lifting weights before endurance training will prevent you from doing that, so endurance athletes should do their endurance training and weight training on different days to ensure adequate recovery between training sessions.

The Ascent Chiropractic Difference

Whether you’re a pro athlete, weekend warrior or just looking to tone up, study after study shows that regular chiropractic care is an essential part of correcting problems, reducing pain and reaching your full potential. We want to be part of your team! To make an appointment at Ascent Chiropractic, call 262-345-4166 or schedule an appointment with our online scheduling app.