If it lasts over two hours, it can generally be categorised as an endurance sport or event. Cycling, tennis, running, adventure sports and races are some forms of such sport that we commonly hear of.

Training for endurance sports is specially done keeping in mind the length of the competition. Adequate nutrition and hydration during training play a very important role in such events.

If you allow yourself to become significantly dehydrated during training, it becomes increasingly difficult to recover between two sessions, resulting in subsequent sessions suffering in terms of performance.

It’s useful to determine sweat rate during training. It is also important to practice sports hydration strategies which will be put to use during the competition. Even during training, it is imperative that you hydrate well.

How much to drink?

 Fluid should only be consumed so that it matches your sweat rate. The aim should be to drink enough so that the loss of fluid is kept below 2% of body weight. The body does not need more fluids than that.

As a general rule, up to one litre of fluid per hour of exercise is good. It is important to trial the food and fluid intake during training. It helps in understanding the capacity of the stomach.

What to drink?

 Performance during an endurance sport can be impacted by dehydration and insufficient fuel supplies to the body. Eating during a lot of sporting events is not possible. That is why a sports drink will help with fluid needs at the same time.

For those with higher sweat rate or for particularly long events, adding some extra salt may help in better retention of fluids in the body. If the weather is hot, some cool fluids will help keep the body temperature from rising too much.

When competing in ultra-endurance events, flavour fatigue can occur as well. Vary your food and fluid intake so that there is consistent drive to drink and eat. The varied flavours of available sports drinks will be very helpful too.

Source: https://www.powerade.co.nz/sports-hydration/hydration-strategies-for-endurance-sports