Holding your breath during a heavy lift is an instinct most people don’t even notice they’re acting on — it happens automatically when a set gets hard. That instinct has a name in exercise physiology, a real effect on blood pressure, and genuine reasons to understand it rather than just do it unconsciously, particularly if you train at home without anyone watching your form. This article explains what’s actually happening, what the major exercise-medicine bodies recommend, and who needs to be more careful with it.
What the Valsalva manoeuvre actually is
The Valsalva manoeuvre is the technical term for forcefully trying to exhale against a closed airway — taking a breath in, then holding it while tightening your abdominal and chest muscles as if breathing out, without actually letting air escape. During a heavy lift, this briefly increases pressure inside your abdomen and chest, which can help stiffen and stabilise your trunk under load. It’s also, separately, why your face can flush and you can feel a rush of pressure in your head during a genuinely maximal effort — that pressure increase affects your cardiovascular system, not just your core.
What it does to blood pressure
The effect on blood pressure is well established in exercise physiology and is the main reason this matters outside of pure lifting technique. The American College of Sports Medicine (ACSM) — one of the leading professional bodies in exercise science and sports medicine — states plainly that inhaling and breath-holding while actually lifting a weight can result in extremely high blood pressure responses, dizziness, and even fainting, and should be avoided during resistance training. This guidance is written specifically in the context of people with high blood pressure, but the underlying mechanism — a sharp, temporary spike in blood pressure during the breath-hold — applies to anyone doing it, not only people with a diagnosed condition.
Why some lifters use it anyway
It’s worth being straightforward about the nuance here rather than presenting a single blanket rule: some strength and conditioning coaching does describe a deliberate, brief use of this technique by experienced, well-coached lifters on their heaviest, near-maximal attempts, specifically for the trunk-stabilising effect during a very short, maximal lift such as a heavy squat or deadlift. This is different from breath-holding through an entire set of multiple reps, and it’s generally discussed in the context of competitive or advanced lifting under supervision, not general home strength training. For the vast majority of training — ordinary working sets, most reps at most loads, and anyone newer to strength training — the simpler and more consistently recommended approach is the breathing pattern below.
A straightforward breathing pattern for most training
The general recommendation for typical resistance training, reflected consistently across mainstream exercise-medicine guidance, is to breathe continuously through each rep rather than holding your breath: exhale during the hardest part of the lift (the concentric, effort-producing phase — pushing a weight up, or standing up out of a squat), and inhale during the easier, lowering phase. This keeps blood pressure more stable through a set and is the pattern worth defaulting to unless you have specific coaching reason and experience to do otherwise.
Who should be more careful
A few groups have a genuine reason to pay closer attention to this rather than treating it as a minor technique detail:
- Anyone with diagnosed high blood pressure — ACSM guidance specifically flags breath-holding during lifting as something to avoid in this group, given the additional spike on top of an already-elevated baseline.
- Anyone with a diagnosed heart condition, who should get individual guidance from a cardiologist or GP on what resistance training is appropriate before starting, rather than relying on general guidance alone.
- Anyone who has recently had abdominal or pelvic surgery, where the raised internal pressure from breath-holding can be a specific concern during recovery — follow guidance from your surgical team on when and how to resume strength training.
- Pregnant women, for whom general exercise guidance typically recommends avoiding sustained breath-holding during exertion; anyone pregnant and strength training should get individual guidance from a midwife or GP on what’s appropriate at each stage.
This is a list of some of the more commonly flagged groups, not an exhaustive one — if you have any diagnosed cardiovascular, respiratory or abdominal condition and you’re unsure, it’s worth asking a GP specifically about resistance training and breathing technique before starting.
General exercise and blood pressure
Zooming out from breathing technique specifically, NHS guidance on preventing high blood pressure lists regular exercise as one of the core lifestyle recommendations, aiming for at least 150 minutes of exercise a week. Resistance training is a legitimate part of that overall picture alongside aerobic activity, but the breathing pattern you use during it is worth getting right independently of how much you’re doing overall.
Practical takeaways for home training
You don’t need special equipment or coaching to apply this. Choose working weights that let you complete your set while breathing in a controlled way rather than needing to lock your breath to force out a rep; if you notice you’re consistently holding your breath through most of a set rather than just a brief moment at the hardest point, that’s usually a sign the weight is too heavy for controlled technique at that point in your training, not a cue to push through it. If you have high blood pressure, a heart condition, or you’re pregnant, treat this article as a starting point for a conversation with a GP or physiotherapist about what’s appropriate for you, not as a substitute for that conversation.