Should You Do Cardio Before Or After Weights?


You’re making a cup of tea. Does the milk go in before the tea bag or afterwards? No doubt the subject of many an office debate. And whilst I can’t answer that, it does share a question in common with the subject of this article – which one should come first?

Two young sportsmen having hard workout on rowing machines in gym.

One of the most asked fitness questions around, to trainers and in forums, is: should I do weights before or after cardio?

People want to know what order of training is going to deliver the most gains. And, in this piece, I’m going to attempt to shed some light on the matter. I can’t promise a definitive answer but I can make things a little clearer. Let’s go.

The cardio vs. weights debate

cardio before weights, girl cardio workout, girl in treadmill

This question has been fiercely debated in comment threads, with some claiming that cardio “kills your gains, bro,” and others insisting that doing cardio before weights will “melt fat off your body like nothing else.”

Who’s right?

Well, like most questions in health and fitness, it depends. The question itself is a loaded one, and raises multiple questions that all need answering individually.

It’s a bit like when a co-worker asks a seemingly simple question like, “what do you do at the gym?” You answer with something along the lines of, “I lift, you know, do a few squats here and there. Weight training,” classically underplaying your years of form and strength.

You think that’s the end of the questioning and you go back about your business, but Chief Inspector Brian has other ideas. This was a loaded gun:

“How much you bench?”, “What should I do at the gym to get ripped?”, “You think you’ll compete?”, “You on the protein?”, “Can you write me a training plan?”

I’m sure that sounds familiar to a lot of you and I feel your pain.

Luckily, the secondary questions raised by the cardio vs. weight training debate are all worthwhile answering in some detail. They give us a better understanding of how to structure training programs and the effects that different training methods have on our health and fitness.

Related: Is Doing Cardio Or Lifting Weights Better For Fat Loss?

Let’s get specific

Doing cardio and weights in the same training program and/or session is known as ‘concurrent training’, I’m going to be using that term for the rest of the article so keep it in mind.

The terms ‘cardio’ and ‘weights’ are also too generic for the purposes of this article – so let’s delve a little deeper into the details of each method.

What is cardio?

men and women in treadmill

Cardiovascular training (a.k.a cardio) is also known as ‘aerobic training’ and is exercise that relies primarily upon oxygen for its main energy source. Cardio training can range from low to high-intensity and can be performed in a variety of different ways, from walking or running to using machines like the rower.

Cardio training is typically sorted into three main styles/categories;

  • LISS cardio (Low-intensity steady state)

This style keeps the heart rate low and usually takes the form of running or exercising on the cross-trainer. You’re essentially plodding along under no real stress – it’s boring but it has useful applications. For example, if you’re focused on strength training but want to include cardio for health reasons then LISS would be a good option. It’s not overly taxing on your central nervous system (CNS), like strength training is, and can be performed with minimal fuss.

  • MISS (Medium-intensity steady state)

This is rarely spoken about in the fitness world but it is a thing. I’m sure you’ve figured out that this style is simply LISS taken up a notch, which raises your heart rate but still doesn’t tax your CNS.

  • HIIT (High-intensity interval training)

There’s a lot of debate around HIIT training and, when it first came to prominence a few years ago, it quickly became the golden child of fat burning cardio. The rise of HIIT led to the fall and ridicule of LISS training – however, this meta-analysis comparing HIIT and LISS training shows LISS definitely has plenty of benefits. HIIT training definitely has its place but people quickly realised how taxing it is on the body, particularly the CNS and joints (if you’re doing sprints). This makes it challenging to include in beginner programs and programs where maximal strength gain is the goal.

What is weight training?

people lifting weights together

Weight training is also referred to as resistance training and can take many different forms. Resistance training is primarily anaerobic in nature which means that oxygen is not its primary source of energy. It is instead fueled by energy found inside muscle cells. Resistance training is performed with free weights (dumbbells, barbells, kettlebells, etc.) and fixed machines. There are quite a few different styles of resistance training but they all seek to achieve one or all of the following; increase strength, increase muscle mass, increase power.

Regardless of your goal, one thing you most likely want is to maximise your performance during training. Remember this because it’s going to play a big role later on.

Two things I’m certain of

lady in treadmill

I’m always hesitant to talk in absolutes – almost all methods have their place and things can change in fitness overnight: a new study being published can make you look very silly.

The rest of this article is going to outline all the different considerations for weight training and cardio, all of which have lots of caveats and justifiable criticisms.

I am, however, confident about the following two statements;

  • If you’re looking to increase strength, muscle mass or power you should never do high-intensity interval training before your session. If you’re doing HIIT properly, a good guideline is that you should not be able to go any longer than 20 seconds for each interval. You will also be totally fried afterwards and in no state to lift a water bottle, let alone execute a resistance training session.
  • The absolute best case scenario is you performing cardio and weight training on different days. Trust me. This allows your body to adapt to one specific stimulus at a time and almost completely negates the interference effect (more on that below).

Butt-out! The interference effect

man working out in a gym with other people

The main argument against ‘concurrent training’ is that the adaptations from cardio training suppress the potential adaptations you can experience from resistance training.

In layman’s terms, cardio kills your gains.

That might sound like ‘bro speak’ but this scientific study appears to back this up. As does this one, showing that training both cardio and weights at the same time can hurt your strength.

So the interference effect is a real thing.

That’s it settled then, the bros were right all along! You’re going to have to bow down to their superior knowledge and accept that cardio is out if you want to grow.

Or do you?

What about this meta-analysis that shows aerobic training can not only preserve muscle mass but help to build it?

So cardio doesn’t kill your gains, it actually saves your gains? Is there a glitch in the matrix?

It actually has the capacity to do both.

Although the interference effect has been shown to exist, concurrent training has also been shown to have benefits for muscle gain and endurance.

This is why context is vital if we are going to make any headway with this topic.

The context in this case is made up of your training goal, training volume, personal schedule, current diet and a host of other factors.

Much like the old teabag debate, I mentioned earlier this topic isn’t cut and dry and so I can’t give you a definitive answer. What I can do is make detailed recommendations so you can decide for yourself where cardio best fits in around your weight training.

Weight training to get strong

If you’re training to get crazy strong, compound lifts are your priority and everything else you do should be geared around that.

This means that cardio never gets done before a weight session.

If you do 45 minutes of LISS on the treadmill before your heavy squat session, you’re going to be in trouble. Say it’s a session where you’ve got 3 sets x 5 reps at 85% of your 1 rep max to smash – well, you’re going to look like a giraffe on roller skates when you get under the bar.

In this case, if you wanted to do some form of cardio that actually complimented your strength training then you could do a form of HIIT training.

HIIT training is explosive in nature and can have some carry over to strength and power development. The considerations don’t stop there though, you also have to consider the impact HIIT can have on your joints and central nervous system. Remember, these have already taken a pounding with all your strength work, so what do you do?

Clue: not hill sprints

First off, you do your best to do HIIT on a different day from your weight sessions. And when I say ‘best’, I mean you make very little exception.

In terms of equipment, you could use the rower or exercise bike as these options will help keep the joint impact low and allow you to be fresh for your next heavy session.

Weight training to get jacked

man lifting weights

Increasing muscle mass and sculpting an aesthetic physique is a common goal, everybody wants to be ripped, right?

So how does cardio fit into your training, in this case?

It once again depends on multiple factors, the main one being your total training volume.

If your resistance training volume is very high then you have to be careful about adding cardio to your schedule.

I’m confident in saying that one or two 30 – 40 minute LISS sessions per week aren’t going to have any detrimental effects. However, they’re by no means necessary if you want to build muscle.

They may help with maintaining body composition during a muscle building phase (the bulk), despite a certain amount of fat gain being inevitable. It’s possible to keep this temporary fat gain to a minimum if you add in a little cardio to your routine.

Weight training to get lean AF

man Lifting weights

Okay, if your goal is to get as lean as possible then cardio can take more of a prominent role – although it’s still secondary to resistance training.

One thing that you must have in place if you’re trying to get lean is a calorific deficit. This is not negotiable and it raises some considerations.

The first is the fact that your energy levels are going to be lower than normal and, since weight training is the priority, it could be argued that it’s best to avoid cardio before taking on the dumbbells.

At the same time, we know that cardio can increase fat-burning potential and, because you have low energy, you might not have it in you to nail some HIIT after a tiring weight session.

Another thing that gets compromised whilst in a calorific deficit is your capacity to recover from training sessions. Doing some HIIT right after the weights, then, seems a bit silly because of it’s highly taxing nature.

What should you do then?

This one comes down to personal preference. If you feel like your weight training is on point and some LISS will help you shed those last few pounds then I would recommend you do it after your weights session.

You may be able to handle HIIT training in your schedule but I would highly recommend doing it on a totally separate day and limiting it to a maximum of two sessions per week.

If you can’t fit in an extra day of training but you really want to do some cardio then I would recommend doing it in the morning, if you go to the gym at night, or vice versa.

Final answer?

So, here we are. After all those suggestions, scenarios and analogies, we’re at the point where I should really draw a conclusion.

Hopefully you feel more knowledgeable and confident about where to plan your cardio in and which method might suit your goal best. I tried to account for as many different situations and practical elements as I could.

I mentioned earlier that the answer to a lot of fitness questions is, ‘it depends’.

That’s still true but I do have an opinion I’d like to share with you. After all, you’ve got this far – I can’t let you leave without some sort of definitive statement.

So what is it?

Everyone should do some form of cardio.

Yup, I believe that having a decent level of cardiovascular capacity is a fundamental part of being a performing human.

I realise there are specialist sports, like powerlifting, that may have no need for cardio but, believe me, cardio can always benefit performance in any arena.

It doesn’t matter if it’s a brisk walk or hill sprints, cardio is important. It may not be as cool or exciting as lifting weights but, if you care about your health and overall performance, cardio should have a place in your routine.

Chris is a performance coach and writer. He works with clients to maximise performance, muscle mass and develop highly productive mindsets.