Summer Running: Training Smart in the Heat

Every year, around this time I start thinking about summer running, and I silently hope: this is the year we get a proper summer. And every year the British weather has other ideas. So let me hedge my bets — I do know we'll get a handful of genuinely hot days. And when those days come, you want to be ready for them rather than caught out.

Here's the honest truth to start with: some runners just handle heat better than others. It's partly genetics, partly acclimatisation, partly how much you've run in it before. I'm not going to pretend there's a magic trick that turns everyone into a cheetah running along the savanna. But that's not the same as being helpless. There's a lot we can do to run smart when the temperature climbs, and most of it comes back to one idea that runs right through everything we do at Full Potential: run to effort, not pace.

Get that one principle into your head and the rest of this post is just detail.

Slow It Down (And Mean It)

When it's hot, your body is doing two jobs at once. Your muscles want oxygen to keep you moving, and your skin wants blood near the surface to shed heat. Both of those rely on your heart, and your heart only has so much to give. Push the pace and your heart rate spikes — not because you're unfit, but because it's fighting a war on two fronts.

This is exactly why we ask you to run to effort rather than chasing a number on your watch. On a hot day, your easy pace might be thirty or forty seconds a mile slower than usual, and that is completely, totally fine. The effort is right. The training benefit is still there — arguably it's better, because you're stressing your cooling system at the same time as your aerobic one.

If you want a yardstick, our Talk Test never lies. On an easy run you should be able to hold a full conversation. If you're gasping between words, you've drifted too hard, heat or no heat. Back off. Remember: harder isn't better. It never has been. The discipline to run easy when it's roasting is a genuine skill, and the runners who master it are the ones still standing strong come autumn.

Dress For It

Less is more here. The biggest mistake I see is runners heading out overdressed out of habit. Strip it back.

A few things genuinely earn their place when it's hot:

• A well-ventilated cap. Keeps the sun off your head and face. Bonus move: take it off at a water stop, soak it, and pop it back on. Instant relief.

• A buff. Soak it and wear it round your neck, on your wrists, or as a headband. A cold, wet buff on the back of the neck is one of the cheapest cooling tricks going.

• Sunglasses. They won't cool you down, but they stop you screwing your face up against the glare. A tense face becomes tense shoulders becomes a tense stride — keeping your face relaxed keeps the whole body relaxed.

• Lightweight socks. Your feet swell more in the heat. A thinner, breathable sock saves you a world of blisters.

Drink To Thirst — But Mind Your Electrolytes

Drink to thirst is still the best general advice when you're running. Your body is good at telling you when it needs fluid.

But here's the catch with plain water: when you sweat, you lose electrolytes — sodium chief among them — alongside the fluid. Your body works hard to keep its water-to-electrolyte balance just right. If you only ever pour plain water back in, you're not truly rehydrating; you're diluting what's left and your body will just flush the excess straight back out. You end up drinking loads and still feeling parched.

The fix is simple. Drop an electrolyte tab into your bottle, especially on longer or hotter runs. It's a small thing that makes a real difference to how you feel an hour in.

Keep Yourself Cool

Some of the best heat management happens around the run, not just during it:

• Run early or late. First thing in the morning is the cooler, calmer, often most beautiful time to be out. Failing that, wait for the evening to take the edge off.

• Chase the shade. Plan a route that ducks under trees or hugs the shady side of the road. It makes a surprising difference.

• Use water on the outside, not just the inside. A splash on the back of the neck, the wrists, the legs — wherever blood runs close to the surface — cools you down fast. Don't be precious about getting a bit wet.

Protect Your Skin

This one's non-negotiable. If you're running in the sun, wear sunscreen. Sweat-resistant, sensible factor, reapplied on the long ones. A great summer of running is no good to anyone if you've cooked your shoulders by the second week of July.

A Word On Racing In The Heat

If you've got a summer race on the calendar, the same principle scales up: adjust your target so your effort stays right. As a rough guide, once it's into the low twenties Celsius you'll want to add ten to twenty seconds a mile to your goal pace, and in genuinely hot or humid conditions (mid-twenties and up) anywhere from twenty to forty. When in doubt, be conservative early — it's far better to feel strong and reel people in over the back half than to be stubborn about a number and fall apart. I've done both. There's no comparison.

And if you can, train under the conditions you'll race in. It's one of the trickiest things for us in the UK — grinding through a cold winter for a spring marathon and then getting ambushed by a warm race day. If you know heat is a possibility, the mental rehearsal of I will slow down and that's the plan is worth as much as any session.

The Honest Bit

I should confess I'm not a natural summer runner myself. I love the long daylight hours we get around Oxfordshire in the summer, but hay fever turns some of my runs into a snotty, watery-eyed negotiation, and I've learned to work around it rather than fight it. That's rather the theme of the whole thing: summer running isn't about forcing your winter self through June and July unchanged. It's about adapting intelligently and enjoying what the season actually offers.

So slow it down when you need to, drink sensibly, dress light, find the shade, and protect your skin. Do that, run to effort rather than pace, and remember that harder isn't better — and you'll have a brilliant summer of running.

Enjoy it. Even if the only sunshine we end up getting has already been and gone!

Thinking about an autumn race? Summer is the perfect time to lay the groundwork. Drop us a line and we'll build a block that gets you to the start line fit, fresh and ready. [Book a coaching package →]