Cardio before or after lifting?

Ask in any gym and you will hear two answers, both stated as fact. Do your cardio first, because it warms you up and burns more fat. Or skip cardio altogether, because it eats your muscle. Neither holds up, and the real answer is more useful than either: where cardio belongs depends on how hard it is.

Cardio does not cost you strength or muscle

The fear first. Schumann and colleagues pooled 43 studies comparing people who did cardio and lifting together with people doing the same lifting alone. Maximal strength and muscle size came out the same in both groups¹. Running or cycling made no difference, and neither did how often people trained, their training status or their age¹.

One quality did pay: explosive strength, the jumping and sprinting end of things. It improved less in the people doing both, and the cost was larger when the two were done in the same session than when they were at least three hours apart¹. If you lift to get stronger or to build muscle, that is a small price. If you play a sport where jumps and sprints decide things, it is worth knowing.

The amount of cardio matters too. An earlier analysis of 21 studies found the interference grew with how often and how long people did their endurance training². It also found running cost more than cycling², though the larger, newer review found no difference between them¹. Either way, a short and easy bout around your lifting sits at the gentle end of all of it.

Lift first when the cardio is hard

When both happen in one session, the order matters for one thing. Eddens and colleagues pooled the studies that tested the order inside a session for at least five weeks. Lifting first and then doing cardio gave better gains in lower body strength. For muscle size, aerobic fitness and body fat, the order changed nothing they could measure³.

Hard work before a heavy lift also costs you on the day. In one study of trained lifters, fifteen minutes of cardio at a moderate effort lowered the best leg press they could manage straight afterwards⁵. Your progress is written by your lifts, so anything that makes you breathe hard, such as a run, intervals or a stiff climb, belongs after them.

Easy before, anything after. The lifts come first because that is where the progress is.

A few easy minutes before make a good warm-up

Easy cardio before lifting is a different thing. It is a warm-up, and the American College of Sports Medicine rates a moving warm-up like this above stretching for getting ready to lift⁴. It raises your heart rate and gets you warm before the first set.

Easy is the word that matters. In the same leg press study, the fifteen minutes that cost the lifters at a moderate effort did not lower their best lift when kept easy, and five minutes at either effort made no measurable difference at all⁵. A warm-up should leave you warm, not tired.

Keep it easy enough that you could talk in full sentences. That is the talk test: the point where talking first gets hard matched a measured threshold of effort almost exactly, on a treadmill and on a bike⁶. And a cardio warm-up never replaces the lighter warm-up sets before each lift. Those still come after it, every time.

A cool down is for comfort

A few easy minutes after your last set bring your breathing back down, and that is a fine reason to do them. Do not expect more. A review of the research found an active cool down does little for how you perform the next day or how sore you feel⁷.

Hard cardio has a day of its own

A rest day is the natural home for a longer or harder session, because there is no lifting on it to get in the way. The one cost the research found was smaller with hours between cardio and lifting¹, and a separate day gives you more than that.

How to put it together

1. Lift first. If the cardio is anything harder than easy, it goes after your last set³.
2. Warm up easy, if you want to. A few minutes on a bike, a walk or an elliptical at a pace you could talk through, then your warm-up sets.
3. Keep cardio inside a session short and easy. The more often and the longer you do endurance work, the more it can cost².
4. Give hard cardio its own day. A run, intervals or a long climb sit best on a rest day, or hours away from your lifting¹.
5. Protect jumps and sprints if they matter to you. They are the one quality that was measurably reduced¹.

What Reckoner does

Reckoner is a strength coach first, and its cardio follows the evidence above. When the plan places cardio, it places one easy, steady bout: a warm-up before your first lift, a finisher after your last, or a cool down in place of the finisher in a beginner's first week. Setup asks whether you want a finisher and a warm-up.

Everything past that is your choice. Six machines are covered: treadmill, indoor bike, rowing machine, elliptical, stair climber and air bike. Tap a cardio row and you can use the machine the way you want, walking, running, steady or intervals depending on the machine, and Reckoner records it as you chose. Where a choice carries something worth knowing, you see a short note with its source. Nothing is ever blocked.

You can add cardio to a rest day, or log it afterwards on any day. Cardio never moves a lift, and a day with only cardio on it is never counted as lifting. Your progress is read from your lifts alone.

For running and lifting across a whole week, Lifting and running in the same week goes further.

Lift first, keep the warm-up easy, and put the hard cardio where it cannot cost you a set.