Cardio Before Lifting? Here Is What That Is Costing You!

Cardio Before Lifting? Here Is What That Is Costing You!

Most people who do both cardio and lifting in the same session do their cardio first. It feels right, the run or the row warms you up, gets the blood moving, and prepares the body for what follows. The strength work comes after. This is the default, and most people have never questioned it.

The research on concurrent training, doing both strength work and aerobic conditioning in the same session, has a fairly clear position on this.

The order is not neutral. What you do first gets the best version of your body.

The ‘interference effect’ is the starting point.

When you train for both strength and endurance, these two adaptations compete with each other at a cellular level. The signalling pathways that drive endurance adaptation (AMPK) suppress the pathways that drive muscle and strength adaptation (mTOR). This is why people who only do cardio do not build much muscle, and why purely strength-focused athletes tend to have limited aerobic capacity despite being very physically active.

When you do endurance work before lifting in the same session, you arrive at the strength portion already fatigued. Neural drive is reduced.

Your ability to recruit fast-twitch muscle fibres is compromised. The loads you can handle safely are lower than if you had come to the bar fresh. The strength stimulus is weaker. Over months of consistently doing it this way, strength development is slower than it would have been with the order reversed.

For most people training for body composition, the answer is lift first.

A strength session requires your central nervous system to be fresh. It demands high force production, precise motor patterns, and the ability to work at or near a meaningful percentage of your maximum. Compromise any of those and the session is less effective. Cardio, particularly lower-intensity aerobic work, has a much lower sensitivity to prior fatigue. A 25-minute aerobic effort performed after a strength session produces a comparable training stimulus to the same effort performed fresh. The reverse is not true.

For HYROX specifically, the question gets more interesting.

HYROX is a race.

It demands that you perform eight functional lifting stations, including sandbag lunges, farmers carries, wall balls, and sled pushes, while running 1km between each one. By the time you arrive at a lifting station mid-race, you are already carrying the fatigue of running kilometres at race pace. You are not performing those movements fresh. You are performing them in exactly the state that doing cardio before lifting produces in training.

This has an important implication. HYROX training should include sessions where you deliberately practise the functional movements while fatigued from prior aerobic work. Not every session, but as a regular component of the training block as your event approaches. Training your body to produce force under aerobic fatigue is specific preparation for what the event actually asks of you. Doing all your training with strength first removes that specificity.

For CrossFit, the standard class structure usually makes the decision for you. Most CrossFit programmes are structured with a strength or skill component first and the conditioning piece second. This is intentional and follows the concurrent training research. If you are arriving early to add cardio before the class begins, you are compromising the strength stimulus. If the class schedule requires you to combine sessions, strength before conditioning is the correct order for most adaptation goals.

Here is a practical framework…

If your primary goal is getting stronger, lift first, every time. The strength session is your priority and the cardio is secondary. Doing it in the other order consistently limits how much stronger you will get.

If your primary goal is improving aerobic fitness and the lifting is supportive, the order matters less. You can do the cardio first without significantly compromising an accessory strength session that is not pushing maximum loads.

If you are training for HYROX, build your programme around both orders. Lift first on days where strength development is the objective. Do cardio first on days where you are practising event-specific conditioning. In the six to eight weeks before your race, include sessions that replicate the demands of the event, including functional movements performed under aerobic fatigue, to prepare the body for what it will face on the day.

If sessions are split across the day, the interference effect is significantly reduced. Strength in the morning and conditioning in the evening, with at least six hours between, is close to the training benefits of doing them on separate days. Where the schedule allows for this separation, it is worth prioritising.

The order question is not complicated once you know what each session is trying to achieve.

The default of cardio first, inherited from a gym culture that treated the treadmill as a warm-up, is not wrong in every circumstance. It is wrong in the circumstances where strength development is the priority, which for most people who train at Priority 6 is most of the time.

Train for what matters most. Give it the fresher body.

Book a free No Sweat Intro at priority6.co.uk to talk through what that looks like for you specifically. Click here

Priority 6 | Abingdon's longest-standing independent gym | Crossfit, Weight Loss, Fat Loss, Strength, Performance, Longevity www.priority6.co.uk | @priority6 | ollie@priority6.co.uk

About the Author

Ollie Campbell is a British strength and conditioning coach, specialist fat loss coach, author of Build The Chain, nutrition coach, and founder of Priority 6 in Abingdon, Oxfordshire.

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