16 things that will probably happen to your body when you start running

Running gets a bad rap when it comes to your body – from your knees to your toenails, as a complete beginner, the horror stories come thick and fast. Yet what actually happens to your body when you start running?

Related: How to start running today: a beginners guide 

1. Your toenails might go black

Sadly, toenails going black is actually a very common running woe. You shouldn’t suffer from black toenails as a beginner, but as you clock up the miles, or start to run more regularly, look out for that tell-tale discolouring. But what causes black toenails? Three different things – a shoe that is too small, a toenail that comes into contact with the roof of the shoe too often, or a runner who uses their toes to grip too hard.

However it happens, the result will be the same – blood vessels under your toenail will break open, which spill blood into the area between the toe bed and the toenail, making it look black. Unfortunately, there’s not too much you can do and as the skin below the nail begins to heal, the black nail will die and fall off and the new nail will start to grow.  

Related: Runners – here’s how to look after your feet 

2. You might chafe

Another common running war wound – chafing is caused by friction as your skin rubs against yourself, or clothing. When it comes to chafing, prevention is key, so make sure you’re wearing the right gear and that your clothes fit well. Apply a lubricant to chafe-prone parts (your inner thighs are often a culprit) and keep your skin moisturised, as it will be less likely to chafe.

If you’re reading this too late, looking after your skin post-chafing can help it recover faster. Shower as soon as you can after running if you have chafing and use an antibacterial soap to avoid infection. It’s also a good idea to use Sudocrem or nappy-rash cream to protect the sore skin.

Related: The best anti-chafe products for runners 

3. You’ll probably get blisters

Blisters are caused by friction between the skin and another service, normally your socks, shoes or a combination of both. If you’re getting painful blisters, you need to look at whether your shoes fit correctly and whether you’re lacing them up in a way that holds your feet securely in position. You might also want to try wearing two thinner socks rather than one pair of thick socks, so friction occurs between the layers rather than against the skin. If you’re constantly getting blisters, it might be worth seeing a podiatrist for gait analysis.

4. Your legs might twitch as you lie in bed on a running day

If you’re lying in bed after a run and you find your legs are constantly twitching, it could be a sign you’re not fuelling your body properly post-run. You lose sodium and calcium when you sweat, two electrolytes that are responsible for muscle relaxation. For women, this can also be a sign you’re slightly deficient in iron. Make sure you include a source of calcium (dairy, beans, lentils etc), salt and iron in your meals after a run.

5. You’ll be able to sleep and focus better

A study of 51 young people found those who ran regularly were able to sleep better, had signs of improved psychological functioning and focused better during the day. To get these benefits, researchers found all you needed to do was run at a moderate pace for 30 minutes a day, five days a week for three weeks.

6. You’ll feel happier

It’s a well-documented fact that runners are happier people. In a recent study by scientists at Glasgow Caledonian University, 89% of runners said that running regularly made them happier, as well as having a positive impact on their mental health and body image.

7. You’ll probably get stitch

Do you find that you get a pain when you run, usually on your right side, that makes you want to stop and walk home? Welcome to stitch. It’s caused by your diaphragm, the muscle that controls your breathing motion. When you run, the attaching ligaments stretch, which stresses the diaphragm and causes pain. To get rid of it, slow down and take full, deep breaths. Rest assured stitch usually affects beginners more, so as your body gets used to running, you should be able to clock up the miles pain free.

8. Your nose might run as fast as your legs

Do you constantly need to wipe your nose as you run? Don’t worry, exercise-induced rhinitis is a common complaint for runners, especially when exercising in the cold or outside. It’s caused by irritated nasal passages, which in turn up their mucus production (nice). Some scientists also believe it’s made worse by pollution, which might be why you find it worse if you’re doing most of your running in the city. Most of the time, it’s just something to get used to, but if it’s really disruptive, talk to your GP about prescription nasal sprays.

9. Your nipples might bleed (normally one for the men)

If you find your stained t-shirt is ruining those post-run photos, don’t panic. As you sweat, you’re left with an abrasive salt on your nipples, which rubs against your t-shirt as you run. It’s not exclusively a male injury, but with women it’s normally a sign your running bra isn’t fitting right, or isn’t made from a moisture-wicking material.

If you are suffering with bleeding nipples, make sure you stay hydrated as you run and protect your nipples with nip guards.

Related: The best sports bras for running 2018 

10. You get a metallic taste in your mouth

Temporarily tasting blood in the back of your throat is again, nothing to worry about when running. It’s actually caused by your red blood cells popping, or releasing iron, which tastes like metal. It’s usually a sign you’re working your body hard and if it only happens once in a while, you don’t need to do anything about it. If, however, you taste blood every time you run, you should book an appointment with your GP to rule out any underlying infections.

11. You’ll need the bathroom…NOW

If you’ve ever had to stop mid-run to look for the nearest pub toilet or public loo, rest assured you’re not alone. The sudden, urgent need to go is common in runners because of the inner jarring mechanisms involved in running. You can make things easier by avoiding sugary foods and caffeine before you run, and sticking to real foods like rice cakes and bananas.

Related: Fast Running Fuel Snacks

12. Your thighs start itching a few minutes into a run

You might find that, three minutes into your run, your thighs start itching like crazy. In some cases, this is dry skin or a natural response to warming up as your capillaries and arteries rapidly expand and stimulate nearby nerves. For some people however, it’s an actual allergic reaction known as exercise-induced urticaria, which can cause itching and flushing, hives and – in extreme cases – breathing difficulties. If you do experience any of these symptoms, check with your GP, however if it’s just itching, keep your skin moisturised, warm up gradually and don’t worry about scratching if needed.

13. You’ll either find running easier in the morning, or at night

If you find it impossible getting to that Parkrun on a Saturday morning, yet love clocking up the miles after work, you’re not lazy, it’s just how your body is programmed. Your natural bird persona – lark or owl – is actually partly determined by genetics and this biological clock is pretty difficult to alter. Natural morning people will hit their lowest body temperature earlier in the night, allowing them to wake up warmer and ready to go. That said, even larks aren’t primed to perform at sunrise, and as Matt Fitzgerald, co-author of The Runner’s Body: How the Latest Science Can Help You Run Stronger, Longer and Faster points out, it’s actually in late afternoon your body is naturally strongest. 

If you do want to clock up the miles in the morning, expose yourself to light as soon as your alarm goes off to wake your body up. Also, remember you naturally become more of a lark as you age, so give it a few years and you’ll have all the morning get-up-and-go.

14. Your knees might crackle as you walk down the stairs

Creaking and cracking in the knees is totally normal. Crepitus, the medical term for that cracking sound, happens when cartilage, the connective tissue between bones starts to age. If you’re a younger beginner runner, weak quads or a tight IT band can also pull the kneecaps out of alignment, exacerbating the wear and tear. Make sure you’re strengthening the muscles that control the hips and knees in your strength training – this will keep your lower half in alignment and minimise the cracking.  

Related: More evidence running DOESN’T ruin your knees                                                                          

15. You might get headaches during, or after, your run

Running headaches stem from a range of causes – from the really simple (your hat or headband is too tight) to the really complex (a proclivity for migraines). Two of the most common reasons are tight muscles (especially in the neck and shoulders) and poor hydration. Make sure you’re not too tense and hunched when you run, and when at home, try loosening off those neck muscles by gently dropping your left ear towards your left shoulder and right ear towards your right shoulder. Also, ensure you’re drinking to your thirst as you run.

16. You might get one bloody, or muddy ankle

That red mark on the inside of your ankle is called a heel whip and is caused by excessive rotation of your foot. Instead of your foot travelling forward, it’s making an arc, causing your heel to nick your anklebone. Try thinking about pushing off through the big toe as you run, so that your foot swings cleanly forward. If you’re finding you inner ankle or shin is really getting sore, it might be worth visiting a physio, to work on single-leg exercises to avoid this happening.