Hydration 101

It’s Summer in Australia and hydration is the hot topic on everyone’s lips. Read on to find out what you should do and why more is not always better.

It’s what you do every day that counts.

In short, hydration needs to be a daily priority, not something you suddenly remember the Friday before a big weekend of training or racing. Here’s where to start:

  • Begin your training in positive fluid balance by consuming two and a half (2.5) to three (3) litres of water per day and 200 to 600 millilitres immediately prior to each session.
  • One of the best ways to hydrate is with water, lemon and sea salt/Himalayan salt to accelerate absorption. Simply add half a lemon and a pinch of salt to every water bottle that you fill.
  • In training, do not wait until you are thirsty. The easiest way is to sip regularly (e.g. at 15 minute intervals). If you find you often forget to hydrate, set an alarm to remind you.

More is not always better.

When it comes to hydration, the key is balance. Under-hydrate and your performance will suffer, but over-hydrate and you run the risk of dilutional hyponatremia – a diluted level of sodium and electrolytes in the blood. Symptoms of dilutional hyponatremia include stomach discomfort, excessive swelling, bloating and increased urine output. In extreme circumstances, death can result as your body literally drowns itself. Let’s avoid this shall we?!

Training and racing – how much?

Keep it simple and start with these guidelines. It is essential that you trial your hydration plan in training – I can’t emphasise enough that nothing new happens on race day.

  • 500-750 millilitres per hour (ml/hr) is sufficient in most circumstances.
  • If you are training or racing in hot conditions and/or your predicted losses are substantial, add 100-200 ml/hr but be careful not to overdo it. Dilutional hyponatremia increases with repeated consumption above 890 ml/hr.
  • In warm conditions, always increase your electrolyte intake to match your increased fluid intake. Start by following the guidelines of the brand you select and ensure your solution contains 0.5 to 0.7 grams of sodium per litre.
  • In extremely hot conditions, you will need to make hydration a priority over nutrition. Take on a little less fuel and focus on the regular timing of your liquids.

Electrolytes – recommended brands:

Do I need salt tablets?

The answer is: it’s relative. If you have a high sweat volume and/or train and race for durations over four (4) hours, then it is worthwhile experimenting with salt tablets in training. Please note however, that salt tablets alone cannot sufficiently satisfy electrolyte requirements, so these should be seen as an addition to your hydration strategy.

In addition, it is important to take into consideration that as you adapt to the heat, for example as your training season progresses, you will excrete less sodium with sweating. Your requirements will therefore decrease and your hydration strategy should change to account for this. Becoming an intuitive athlete is crucial to help determine this.

What about coconut water?

The natural sugars and electrolytes are great during, or after, an intense exercise session. Be mindful though, coconut water is high in potassium and contains minimal sodium, so it should not be your sole means of replacing sweat losses. In addition, one serve contains 15g of carbohydrates, so it is not to be treated like water. A couple of times a week is sufficient.

What about sports drinks?

The short answer is no. They are full of artificial sugar, preservatives and colours, and there are much better options. Here’s a great homemade recipe for you:

Homemade Sports Drink: 750ml of water, 1 tablespoon of rice malt syrup, the juice of one lemon and a pinch of sea salt. This is perfect for a short session on the bike (<90 minutes) and recovery from your longer sessions.

In summary, focus on what you do daily and formulate a plan to practice in training. As always, these are just guidelines. Please remember that biology is not math and just like why we don’t count calories, numbers are just a place to start. My advice to you is to become an intuitive athlete and commit to trial and error to perfect your training and racing strategy.

Still not sure?  Book a consultation with me here. I’d love to help.


Barr SI et al. (1991). Fluid replacement during prolonged exercise: effects of water, saline, or no fluid. Medical Science Sports Exercise, 23(7), 811-17.

Noakes T. (2012). Waterlogged: The Serious Problem of Overhydration in Endurance Sport. Champaign, IL, Human Kinetics.

Rogers IR. (2001). Fluid and Electrolyte Balance and Endurance Exercise: What can we learn from recent research?, Wilderness Medicine Letter, 18, 3.

von Duvillard SP et al. (2004). Fluids and hydration in prolonged endurance performance. Nutrition, 20(7-8), 651-6.

von Duvillard SP et al. (2008). Sports drinks, exercise training, and competition. Current Sports Medicine Reports, 7(4), 202-8.

Image credit here.

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