First the disclaimer. Nutrition decisions and diets have become the new cults. Vegans, paleos, “ketos”, intermittent fasters, etc that live and think there is no better option for everyone but their way. If you know what you are doing after talking with a professional, please continue doing so. These are the basics that I’d explain to beginners joining our activities. What has worked for us. I am not a nutritionist nor a doctor.

Ideally, eat some hearty breakfast well before the outing. In my case, for strenuous exercise (hard trail running mainly) it should be 3 hours before, to avoid digestive problems. For swimming, slower hiking, etc can be less. Some people are able to eat just before any outing with no problem. Test yourself beforehand.

What to eat? I’d avoid anything that requires long digestion or can be rough for your stomach: fatty meats, fried stuff, too high fiber food… I would even avoid any new food/restaurant the previous night and definitely for breakfast if I’d be going to a longer/trickier route. I eat what I know I’ll digest easily. Mainly carbs and some proteins. Fruits, muesli, cereals, milk, pasta. If possible not too sugary (lower glycemic index foods) so that the energy is released slower. I drink plenty too before leaving home.

In summertime, I usually bring 0.5-1 liter of liquids per hour of expected time walking/running. Your sweating level would define how much you need, but it is always better to carry above your requirements than having too little under the scorching sun. If you are going to be around relatively clean streams or you have access to public toilets with water, a filter will allow you to refill and carry significantly less weight on your bag.

Sports drinks. For lower-level efforts, you will not need them. If you go long, strenuous, and, above all, sweat a lot then it is time to consider them to, among others, replenish electrolytes. I would not recommend Gatorade like drinks that are too acidic. I learned the hard way, in a 3 hours race only drinking them, how harmful they can be for your enamel. There are other options with a more neutral PH. I usually bring a separate 500ml bottle with a concentrated Perpetuem mix, sometimes adding a small amount of instant coffee.

Apart from electrolytes, it provides carbs and a small amount of proteins.

For longer routes or where I expect to stop several times, I bring some solid food: a sandwich, fruit, nuts, bars… The goal is, again, to replenish salts and carbs in as tasty/convenient an option as possible.

Other related topics talked about in our outings:

Hyponatremia is a low sodium concentration in the blood. It is not uncommon among long-distance runners or hikers. Due to plain water over drinking or excessive sweating without electrolyte replenishment. The symptoms are very similar to dehydration. So try to drink what your thirst requires you. Do not over-drink. The old ads telling you that “you should never feel thirst or you were late already” were just marketing. Dangerous marketing.

Runners hitting the wall. The amount of carbs (glycogen) that you can store in your body is limited. Basically, you can store in your skeletal muscles and liver up to 350-500g. It is the main energy source for high-intensity exercise. The easier you go the more fat you will burn instead. Although you will need some glycogen too. Those that deplete all their glycogen feel a sudden energy drop that can feel like hitting a wall. I felt it once, in my first duathlon. I had lost an energy gel that I should have eaten midway, in the last 500 meters I tried to sprint to pass some runners in front of me and… suddenly I felt like within a car that was completely out of gas (it had happened to me once also 😅), pop, pop, pop… and barely able to walk to the finish line. Easily solved in that case. I ate tons of sugary food and I felt fine in no time.

Fat burning efficiency. Everyone, even skinnier ones, carry fat enough to fuel activities for long. Consider that 1 kg of fat is 9,000 kcal, vs 4,000 for carbs. And everyone carries quite some kilograms of fat on their body. Even a skinny girl (45kg 12% fat) is carrying more than 5kg = 45,000 kcal of energy on them. You will never use it all, but just for your understanding. Therefore the better you make your body burning those fat storages, the better you will be long-distance hiking/coasteering/swimming/running.

The fitter you are, the easier (cardiovascularly) that usual activities (hiking, coasteering…) will become and more fat instead of glycogen that you will burn. There are several methods to improve your fat consumption. A runners’ classic is fasted medium-effort sessions. Search online if you want to know more. But never try these things in a new route or when attempting anything that could be challenging for you. You will feel better physically and mentally after the mentioned hearty breakfast. The brain is the main carb user in your body.