The things that go wrong when you start running

A stitch is the sharp pain under the ribs, usually on one side, that arrives without warning and makes running impossible while it lasts. Its exact cause is not settled — irritation of the membrane lining the abdominal cavity is the most commonly offered explanation, and it remains an explanation rather than a proven mechanism.

What is reliable is the pattern of when it happens. Eating too close to running, drinking a large volume immediately beforehand, and starting too hard all make it more likely. Slowing down and breathing out deliberately as the foot on the affected side lands usually clears it within a minute or two, and it does not indicate anything is wrong.

Blisters are friction plus moisture. The two fixes are technical socks, which move sweat away instead of holding it, and shoes that fit — most beginner blistering comes from a shoe that is fractionally too small or too loose rather than from soft feet. A hot spot noticed mid-run will become a blister if ignored and usually will not if you stop and adjust the sock.

Black toenails are a length problem. The toe is contacting the front of the shoe on every downhill step, bruising under the nail. This nearly always means the shoe is too short — feet swell during a run, and the shoe that fits perfectly in the shop is the one that does this. A thumb’s width in front of the longest toe is the conventional allowance.

Chafing appears at whatever distance is long for you, in a location specific to your body and your clothing, and it is worse in the wet. The two prevention routes are removing the seam that is doing it and lubricating the area before the run, and both work.

The thing to know is that it is prevented rather than treated. There is no mid-run fix, and by the time it is noticeable it is already done. Anybody starting to run for longer than an hour should sort this out in advance rather than discovering the location experimentally.

New runners frequently ask about breathing technique, and there is far less to it than the volume of advice suggests. Breathe through whatever is comfortable, in whatever rhythm arrives naturally. Deliberate patterns are something a small number of runners find useful and most never think about.

The reason breathing feels like the problem is nearly always that the pace is too high. Being unable to breathe comfortably is the symptom; running faster than an easy effort is the cause, and slowing down fixes it more reliably than any technique.

Boredom ends more running than injury does, and it is treated as a character failing when it is a design problem. The same route at the same time alone is a hard thing to keep doing, and there is no reason to.

The fixes are structural: run with other people, vary the route deliberately rather than by accident, give some runs a purpose beyond distance, and put a fixed commitment in the week that involves turning up somewhere. Almost everybody who has been running for years has one of these in place, whether or not they think of it that way.