Hot days are no reason to skip training. They are a reason to train differently. Four things that make the difference.
1. Drink enough, spread over the day
You lose a lot of fluid overnight when it is hot. Start drinking in the morning instead of pouring down a large amount just before training. About half an hour before your session, half a litre of lukewarm water works best. Lukewarm feels less refreshing, but your body takes it up faster because it does not have to warm it first.
2. Listen to your body
A dry mouth and rising thirst are the first signs that you are short of fluid. Act on them instead of pushing through. Keep going and you often end up with a headache and circulation trouble. Dizziness, nausea or goosebumps in the heat mean stop.
3. The right clothing
Technical fabrics move sweat to the outside, where it evaporates and cools you. Cotton soaks it up and stays wet on your skin. Outdoors, add a hat and sun protection.
4. Adjust the intensity
In the heat your body can do less. It spends energy on staying cool, and that energy is missing in your session. Add the loss of fluid and electrolytes on top. On days like that, take some weight off the bar, rest a little longer and move the hard session to early morning or evening.
How much should you drink?
As a baseline, work with roughly 30 to 35 millilitres per kilo of body weight per day. At 70 kilos that is a good two litres before any training at all.
Each hour of training in the heat adds another half litre to a litre on top. The simplest check is your urine: pale means enough, dark means too little. The second check is the scale. Weigh yourself before and after a long session. Every kilo lost is fluid and should come back over the course of the day.
When you need electrolytes
For an ordinary hour of strength training, water is fine. Electrolytes earn their place when you sweat heavily for more than an hour, train several times a day, or are out in the midday heat.
It does not take an expensive powder. A pinch of salt in your water with a little fruit juice covers most of it. If you find white marks on your shirt you lose a lot of salt and should err on the generous side.
Your body adapts to heat
After one to two weeks of training regularly in the warmth your body adapts. You start sweating earlier, your sweat gets thinner and carries less salt, and your heart works more calmly at the same load.
Which means the first hot days are always the hardest. If the first heatwave feels as though you have not trained for three months, that is normal. Take the pace out during that period and keep going rather than stopping altogether.
Better to train outside or inside?
In high summer, inside is usually the better call. The temperature is steady, there is shade and water, and you can run your programme as planned. Outdoors, train before nine in the morning or after dinner.
Is strength training worth it in summer?
Yes. Strength is the base everything else is built on, and three months off cost you more than they give you. Twice a week with a bit less weight beats not training at all. Training is not a sprint, it is a long run.
Want to know what makes sense for you right now? In the entry check we look at where you stand and write the plan afterwards. More on the personal training page.