An ankle or knee injury
Call 999 or go to A&E if you heard a crack, the joint has changed shape or is pointing at an odd angle, it's numb, tingling or has pins and needles, or the skin has changed colour or is cold. Get help from NHS 111 if it's very painful, badly swollen, or you can't put weight on it or walk more than a few steps, and for a knee that locks, gives way or painfully clicks.
Sources 29, 30
A snap at the back of the ankle
Same day: a sudden snap or pop at the back of the heel or calf, or a feeling of being kicked there, then walking flat-footed and being unable to push off, stand on tiptoe or climb stairs. It could be an Achilles tendon rupture or a broken heel bone. Go to A&E or a minor injuries unit, or contact NHS 111.
A sudden snap or pop at the back of the ankle, or you can't stand on tiptoe: a possible Achilles tendon rupture.
A knee that pops and swells
Go to A&E (accident and emergency) if you've injured your knee and it has changed shape, it becomes very swollen very quickly, you felt a pop or snap, you can see bone sticking out, or it's bleeding heavily. Don't drive yourself: ask someone to take you, or call 999 if the pain means you can't move your leg to get there.
An ankle that keeps giving way
An ankle that keeps giving way months after a sprain.
Stop for the day
At the first tightness at the back of your thigh, in your calf or in your groin, stop rather than doing one more sprint. Stop too if you feel dizzy, sick or far more breathless than usual.
Bone or shin pain
Pain in one spot on a bone that's worse with jumping or running, eases with rest and hurts when you press it: stop jumping, as it can be a stress fracture, and see a GP. See a GP too for heel pain that hasn't improved after 2 weeks of looking after it yourself, or shin pain that's getting worse or isn't improving.
A knock to the head
Anyone who might have a concussion stops at once and doesn't play, train or do PE again for at least 24 hours. Get them assessed within 24 hours by a healthcare professional or NHS 111, and call 999 for red flags such as getting drowsier, repeated vomiting, a fit or a worsening headache (the full list is below). Fewer than 1 in 10 concussions involve being knocked out.
Stop and get medical help
If you get chest pain or pressure, feel faint or dizzy, are unusually breathless, or your heart races or beats irregularly during exercise, as our plans advise.
Call 999 (911 in the US)
Stop and call 999 for:
- Chest pain or discomfort that doesn't go away (it can feel like squeezing or pressure), pain that spreads to your arms, neck, jaw, stomach or back, or chest pain with sweating, feeling sick, light-headedness or breathlessness.
- Someone who faints while exercising.
- A pounding, fluttering or irregular heartbeat that doesn't go away, or comes with chest pain, breathlessness or feeling faint.
- Severe difficulty breathing: gasping, choking or not able to get words out.
Source 31
During any session
Stop straight away if you feel any pain or become unwell, the NHS says, and contact 111 if your symptoms worry you or don't go away.
A dull ache in your muscles for a day or two after something new is normal. Joint pain that's sharp, gets worse during a set or lingers into the next day means switching to the easier option, and seeing a GP or physiotherapist if it carries on (our plans' rule). Our muscle soreness guide has more.