How Does Running A Half Marathon Affect Your Body?

Recovery from your half marathon starts with understanding the impact on your body.

If you ran an Autumn half marathon (like our Windsor event), you’ll already know that your body needs careful recovery. It’s not just the 13.1 miles you’re recovering from, it’s all the training that led up to it.

Exactly how does a long race like a half marathon affect the human body, and what are the best recovery strategies? Here are the 5 most common effects – and what you can do next.

Muscle inflammation

Running a half marathon will inevitably lead to some level of muscle inflammation. This isn’t necessarily a bad thing, but it explains some of the aches, pains, and stiffness you might be experiencing. The best recovery starts way back in your training plan – if you increase mileage gradually, you’ll minimise inflammation. Top tip: don’t rush half marathon training!

Minor injuries

Thankfully, injuries are uncommon in half marathon runners. But you might experience lower body issues, including shin splints, plantar fasciitis, or muscle pain to your calves, hamstrings, or quads. Muscle aches can be treated with rest and gentle stretching. For anything else, rest and then think about a visit to a sports physio if the pain persists. Let any injuries heal completely before you start running again.

Black toenails

If you know, you know! Damaged toenails is one of the potential side-effects that no runner really likes to discuss. If it happens to you, don’t try to perform home surgery on the nail. Visit your GP who will be able to quickly drain it. If it’s not bothering you, you can just leave it. Be warned, the nail will almost certainly fall off. You may need to keep an eye on the same nail in future, as these things have a tendency to reoccur.


Sometimes we end up with blisters after a long race, despite our most conscientious efforts! If you’ve got blisters on your feet, heels, under your bra straps, or anywhere else, the best thing to do is let them breathe. Make sure they are kept clean, and then let them dry (uncovered). Try to wear shoes and clothes that don’t touch them. They shouldn’t take too long to recover.

Coughs and colds

Some people find that running longer distances can impact their immune system. If you come down with a cold or virus after your half marathon, the physical stress of the race could have compromised your immunity. The best way to recover is rest, and a renewed focus on healthy nutrition and plenty of hydration. Get as much sleep as you can, eat nutrient-dense homemade food, and drink lots of water. Your body will soon re balance itself.