Should I Run Before or After a Workout?

Sport & Activity

Running before a workout can improve endurance but can also interfere with muscle building. Beware of these potential mistakes.

Last updated: 30 June 2022
6 min read
Should I Run Before or After a Workout?

Research suggests that runners who cross-train are more efficient runners with better performance. And the reverse may be true too: people who regularly resistance train and run often have better endurance and aerobic capacity than those who don't run. Combining running and strength training may lead to a host of health benefits and even better physical performance. The question is, which activity should you do first: cardio or weightlifting?

The answer? It largely depends on what your fitness goals are. Establishing clear goals before you jump into a fitness plan is the key to ensuring that you train in the most optimal way.

Begin With Some Cardio to Warm Up

Starting your gym routine with some light cardio can effectively warm up your muscles before your workout. A warm-up will gradually increase blood flow to your working muscles. This increases the flexibility of your muscles and joints before they are put under greater strain, such as they would be on a run or against the resistance of weights. Warming up with cardio has been shown to reduce the risk of injury.

You could:

  • Jog on the spot
  • Lightly jog on a treadmill
  • Do star jumps
  • Use a skipping rope

Aim to warm up for five to ten minutes before any workout. This type of cardio is performed at such a low-intensity it shouldn't interfere with your training session. It can—and should—be done before a weightlifting session or a run.

But what about cardio performed at a higher intensity or for longer? Should it be done before or after weights? Let's take a look.

If You Want to Build Muscle ...

For people looking to build muscle, the main focus of your gym routine should be lifting weights. Specifically, hypertrophy training. That is progressively overloading your muscles by lifting progressively heavier weights, working in a rep range of 8 to 12 reps. Lifting heavy weights and pushing your body will cause microtrauma and inflammation in the muscle tissue and deplete glycogen (carbohydrate) stores.

As a part of the repair process, muscle protein synthesis occurs. This rebuilds muscle tissue stronger and bigger than it was before. So that next time your muscles are exposed to the same training stimuli, they are better equipped to handle it.

Why is this important information to know? Because you need to have energy to lift weights to get the results. If the weights you're lifting aren't heavy enough, or you can't complete the required number of reps, sets or total volume, you likely won't expose your muscles to a big enough training stimulus.

Therefore, the all-important hypertrophic process won't occur and you won't experience muscle growth.

So if you want to build muscle, you need to use your energy to lift weights. Running prior to lifting will deplete the circulating energy stores you need for heavy lifts. Plus, the repetitive movement of running reduces the efficacy of muscle contractions. What that means is you tire yourself out and muscle contractions are less effective. Your form might even become compromised as a result of the fatigue and repetitive contractions necessary to sustain a run, according to a 2016 study published in the Journal of Strength and Conditioning Research. Researchers examined the effects of performing moderate-intensity aerobic treadmill running prior to hypertrophic-style resistance exercises. They measured the rate of perceived exertion (RPE) and completed repetitions, amongst other metrics to establish the effects.

The researchers found that the total number of repetitions, average power and velocity were all markedly reduced in the group who did cardio before weights. In addition, their RPE was higher even with a lesser volume.

If building strength and muscle is your main goal, do aerobic exercise after your workout. However, keeping it light is better. Overdoing it after a full-body or heavy leg workout will only increase the amount of recovery time required. Ideally, try to avoid back-to-back cardio and weights.

If You Want to Lose Fat …

For people who want to lose fat, it's a good idea to alternate between running before and after your resistance training workout to get the best results.

When you lift weights prior to running, you deplete your glycogen stores. This means your energy levels might be lower on your run, but it also means your body is forced to tap into your body's fat stores. This helps maximise fat loss.

Building muscle improves your body composition, i.e. the ratio of muscle to fat. Weightlifting helps to build and retain muscle mass, which has a beneficial metabolic effect. Studies show higher percentages of muscle mass are linked to a higher metabolic rate. That means you'll burn more calories at rest. So ensuring that you carve out time to do weightlifting may accelerate calorie burning and weight loss over time.

That being said, running is also beneficial for weight loss. Particularly a slower-paced, long run, combined with high-intensity interval (HIIT) running. Cardiovascular running is done in the "fat-burning" aerobic heart rate zone, in which your body burns fat for fuel. Albeit, slowly.

Combining it with anaerobic running is best because this burns more total calories. Anaerobic running involves running at 80 percent or higher of your heart rate max. It's performed without oxygen, meaning your body can only sustain it for short periods of time. This is due to excess post-exercise oxygen consumption (EPOC), in which your metabolism is elevated for up to 24 hours post-workout.

If you're on a calorie-deficit diet—which is optimal for weight loss—your energy levels may be lower than usual. That's why it's a good idea to alternate between running and weightlifting to ensure that you don't overwork your body while still reaping the benefits from each.

If You Want to Increase Endurance …

Lifting weights helps running economy and performance, so it can provide a huge benefit when incorporated as part of a running training plan. However, running should still be prioritised as a way to increase endurance and stamina.

It's best to retain your energy for your run. Starting off a run feeling fatigued interferes with your aerobic capacity. If your glycogen stores are depleted, your body won't be able to sustain running for long.

Studies show that glycogen depletion negatively affects endurance performance. That's why many runners carb-load before a big race or training day—they are preparing their body with the fuel they need to perform. The same concept can be applied to your training. Prime your body by starting a workout off with a short jogging warm-up, particularly if you are running longer distances.

Afterwards, incorporating some lighter weights performed for 15 to 20 reps will help to increase muscular endurance. The higher repetitions develop your type-1 slow twitch muscle fibres, which help running performance, especially long-distance running or a high training volume. These muscle fibres are fatigue resistant and have high concentrations of mitochondria and myoglobin to increase aerobic metabolism.

When deciding whether you should run before or after a workout, you have to examine your fitness goals. Spacing out your running and strength-training workouts on different days is optimal, to allow recovery and ensure that you can put your all into each session. But if you need to, follow our guidelines to help you decide whether to run or lift weights first.
Should I Run Before or After a Workout?

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Originally published: 6 January 2022