Somewhere around the third hour, when the humidity is sitting somewhere above 80% and the road is climbing again and your kit has been soaked through since kilometre twelve, you will understand very clearly that what you ate and drank this morning matters enormously.
Nutrition in the heat isn’t a marginal gain. It’s the difference between finishing strong and getting pulled from the ride in the back of a support vehicle, wondering what went wrong.
Here’s what goes wrong, and how to stop it happening.
Your sweat rate will shock you
Riders who train at home in temperate conditions routinely lose between 500ml and 1 litre of fluid per hour during hard efforts. In Phuket — 33 degrees, brutal humidity, full sun — that can double. Some riders lose close to 2 litres an hour in those conditions.
Your body does not give you clear, reliable signals that this is happening until it’s already a problem. Thirst is a lagging indicator. By the time you feel genuinely thirsty out there, you’re already behind.
The rule is simple: drink before you’re thirsty, eat before you’re hungry, and do both more often than you think you need to. Set a timer on your computer if you have to. Every 15-20 minutes, something goes in.
Water alone isn’t enough
This is the one that catches experienced riders out. You’re drinking consistently, you’re not skimping on fluid, and you still feel awful by the afternoon. The reason, almost always, is sodium.
When you sweat heavily, you lose sodium — a lot of it. Water replaces the fluid but not the electrolytes, and the imbalance causes a cascade of problems: cramping, fatigue, headaches, and in serious cases, a condition called hyponatremia that is exactly as unpleasant as it sounds.
Bring electrolyte tabs or powder. Use them. Not occasionally — in every bottle, all day, every day you ride. This is not optional in Phuket’s climate. It is as fundamental as the water itself.
Eat more, eat earlier, eat often
Your caloric burn in the heat is higher than at home — your body is working to cool itself as well as to power the bike. On top of that, the heat suppresses appetite, which means you often don’t feel like eating precisely when you most need to.
Don’t wait for hunger. Eat something in the first hour, before the fatigue sets in and before your gut becomes reluctant. Small amounts regularly is far more effective than waiting and then trying to catch up — by the time you’re actually hungry on a hot ride, your blood sugar is already crashing and your ability to process food is compromised.
What to eat? Whatever you can stomach. In the heat, gut sensitivity goes up and the appetite for sweet, thick energy gels goes down sharply for a lot of riders. Real food works well — rice balls, bananas, savoury snacks, bread. The local options at roadside stops along the route in Thailand are genuinely good and your body will often take to them better than processed sports nutrition.
The morning matters as much as the ride
You cannot eat your way out of a bad breakfast on the road. What you take in before you leave has a two-to-three hour window to actually be available to your muscles, so the morning meal is load-bearing.
Carbohydrates — rice, bread, fruit, whatever sits well with you — in a quantity that reflects the day ahead. Not a token bowl of cereal. A proper meal. And start hydrating with breakfast, not at the start line.
Coffee is fine. Coffee and nothing else is not fine.
Recovery: the bit everyone skips
After a hard day in the heat, your body is depleted in ways that a beer and a big dinner, as satisfying as that sounds, won’t fully address. In the 30-45 minute window after you stop riding, your muscles are primed to absorb carbohydrate and protein for repair and recovery. Leave that window empty and you’ll pay for it on day four when your legs have nothing left.
A recovery drink, a snack with both carbs and protein, a banana and some yoghurt — whatever you can face. Get something in before the shower, before the social hour, before the meal. Your legs on the next day’s climb will thank you.
One last thing
The food in Phuket is exceptional. The local cuisine is built around rice and fresh ingredients and flavours that will make your standard cycling nutrition feel very beige indeed. You’re not in a place where eating well is a chore.
Enjoy it. Just make sure you’ve done the work on the bike first.