Guest Article: Hydration Tips for Triathletes

Harbourman 2018_Cool Down

Multiple times National Champion, Dr. Carolyn Hayes, gives her tips for staying hydrated before, during and after your training sessions and races:

Hydration Ideas for athletes

Given the recent warm weather, it’s important to be thinking about hydration, or more importantly, avoiding dehydration. As athletes, we need to consume more fluids.

When we exercise, we elevate our body’s temperature and the main mechanism we use to cool it down is by sweating (thermoregulation). Heat is removed from the body when beads of sweat on the skin evaporate, resulting in a loss of body fluid. The amount we sweat and increases with a rise in ambient temperatures (our current warm weather) therefore, we lose excess fluid and electrolytes. It is this cycle of dehydration that may occur which increase the risk of heat illnesses. The worst of these illnesses being heat stroke.

Dehydration will impact not only your performance in training/racing but also affect your mood, appetite and sleep (you’re going to eat more thinking you’re hungry when in fact you’re just dehydrated). Keeping on top of your hydration will reduce the risk of heat stress, maintain normal muscle function and prevent performance decreases due to dehydration.

Thankfully, most of us are pros at keeping on top of our own hydration already and if you’re not it’s pretty simple to get there.

Pre Training/Racing

The best way to gauge your level of hydration is by taking a look at the colour of your urine – see the chart below. This is pretty basic and something most athletes are pretty good at keeping an eye on. Some athletes advocate hyper-hydrating prior to events (drinking in excess of their usual intake) however, studies have shown that this isn’t the way to do it (you just end up going to the toilet more and losing excess electrolytes!) plus you’ll be heavier.

Excessive over hydration can cause dilution of blood sodium levels (hyponatraemia) causing symptoms such as headaches, dizziness, coma, and in severe cases, death. Personally if I know it’s going to be hot, I just make a conscious effort to have water bottles with me everywhere I go throughout the day. If I would normally take on board 3 bottles a day I’ll up it to 4. When on-the-go or working it’s more difficult to carry a bottle around with you but everyone has access to water during the day so it’s important to keep topping up.

Hydration Chart

During Training/Racing

During training or racing you’re sweating regardless of the heat. With the warm weather we currently have, you’re working harder and sweating even more which means you’re losing excess fluid and electrolytes. If you’re not careful and taking on board regular fluids (sips throughout) you’re going to start cramping and slowing down.

Everyone handles heat differently and will have different sweat losses. Knowing your sweat rate can give you an indication of how much you should be drinking during exercise. No one likes training on a full stomach and the same goes with liquids. You want to consume the majority of your fluids 1-2hr pre-exercise and then just take sips as needed. During training/racing depending on duration you’re going to have to keep the fluids coming but don’t gulp down 500ml between reps or in one go on the bike/run! Adding an electrolyte tablet to a water bottle is a great idea in this weather.

As a rule of thumb:

  • Plain water is fine for events <1hr 
  • Events >1hr or multiple sessions in the same day- then your replacement fluid should contain carbohydrates, sodium and potassium (sports drinks, powders, Zero tabs etc)

Harbourman 2018_Water

Post Training/Racing

Post-training/racing, you want to start replacing and replenishing any lost fluids and electrolytes (sodium). Sodium in fluid improves fluid intake as it stimulates the thirst mechanism, promotes both carbohydrate and water uptake in the intestines, and reduces the volume of urine produced post-exercise.

If you’re hydrated well pre and during you don’t need to start gulping down fluids. However, if you finish your exercise and you’re thirsty, you are dehydrated and need to get a bit more in. Keep an eye on your urine colour which will inform you when you’re back to being hydrated appropriately. Electrolyte tablets or salt tablets to prevent cramping are a good idea both during and post exercise.

Sheephaven Half_Bike

To calculate sweat loss you need a pre and post exercise weight:

  • Pre exercise weight (empty bladder and as close to the start of your session as possible)
  • Post exercise weight (try to towel off any excess sweat from your body) 
  • Calculate the difference in weight

This will inform you of how much fluid you’ve lost (i.e. the difference between your sweat losses and fluid intake). This is the easiest way to monitor sweat losses and can be used to give you an idea of how much fluid to replace during training sessions and competition.

Final take home:

Dehydration can take time to correct - by the time you’re thirsty it’s too late and you’re playing catch up.

Hopefully everyone is enjoying training in the warm weather but do bear in mind the following:

  1. Inspect your urine pre + post training (the colour shouldn’t change materially if you’re hydrating adequately)
  2. Aim to match your sweat rate with fluid intake as best you can.
  3. Take on board more water in warm weather - if you normally drink one bottle on a 1-2hr spin take two. 
  4. Weighing yourself before and after provides good feedback on your level of hydration
  5. Sweat contains electrolytes and with the warm weather you’re losing more of them so try some electrolyte replacement tablets.

You can follow Dr. Carolyn Hayes' journey in triathlon on her Twitter and Instagram accounts.