We all know how important water is to our everyday health and well-being.
It’s something that most of us do without much thought and our bodies certainly thank us for it.
With 50-60% of the adult body being made up of water, it isn’t a surprise that water has many important roles to play including maintaining blood volume and regulating body temperature.
For those who have a high physical output, hydration and replenishing fluid lost during exercise is important to ensure you can directly recover and maintain the overall health of your body.
This loss of fluid is the result of sweating, as your body cools itself during a tough session to maintain a healthy body temperature. If you don’t replace these fluids, then dehydration can occur.
There are a number of factors – aside from a tough workload – that contribute to a greater loss in fluid including temperature and humidity. So if you’re playing or competing somewhere with those sorts of conditions, then getting your hydration right is vital to optimum performance.
Get your fluid intake wrong and dehydration can have brutal effects on your body, reducing your physical performance, cognitive ability and impact key bodily functions.
As dehydration worsens, your heart rate and body temperature both increase significantly and the perception of how hard the exercise feels intensifies – especially in hot or humid conditions.
Impaired concentration, decision making, skill level and execution can also occur as dehydration increases.
Dehydration can also increase the risk of nausea, vomiting, diarrhea and other gastro-intestinal problems during and after exercise.
So, how do you manage your fluid intake before, during and after working out?
The type and duration of exercise are key considerations to fluid intake during exercise, as well as the conditions you’ll be training in.
It’s difficult to place a ‘magic’ figure on how much you should be drinking with so many variables, but as a rough guide you should be looking to:
- Pre-training: Two hours prior to training or the evening before, drink 10ml/kg of body weight. If it’s a long/hot/outdoor session, make this from an electrolyte based drink, or sports drink.
- During: Drink regularly throughout where possible. A guide is up to 250ml every 15 to 30 minutes
- Post-training: The amount to consume here is based on what was lost. You want to replace 150% of what you lost, which is why weighing before and after is important where possible (or at least on occasion so you have an idea on how much you tend to lose). This should be over a number of hours, it doesn’t have to be immediately.
Drinking enough during exercise is certainly necessary to replace lost fluid, with the amount consumed during exercise ultimately replacing a majority of the fluid lost through sweat.
As mentioned, sweat rates are individual and as such fluid replacement is also individualised. An example for an AFL player who weighs 85kg and loses 2L (2kg in a game), would be to aim to drink 1-1.5L during the game. Sipping on fluids on the field and bench where possible, but using the quarter breaks to consume larger amounts around 150 – 200ml. An athlete does not need to finish the game at the same weight they started, but ideally they should lose 2% of total body weight or less.
In some conditions water is sufficient for hydration, in others you may benefit from an electrolyte based fluid, or even one with some carbohydrates as well.
For those heavy sweaters, or intense exercisers, adding electrolytes to fluids can be important for a few reasons. When replacing what we lose in sweat, it isn’t only about water, it is also about the electrolytes we sweat such as sodium. By replacing electrolytes – in particular sodium – this also helps with fluid balance which means fluids consumed after exercise are retained and not lost through urination.
Your sweat rate is also a contributing factor to your required fluid intake around exercise, they vary from person to person so having an understanding of your own individual sweat rate is important.
Listen to your body and observe your response to different types of exercise, conditions and types of fluids to work out what’s right for you. This will help you understand and adjust accordingly as you move through pre-season, training, events and recovery.
Ultimately we are aiming to stay hydrated, and lose less than 2% of body weight during exercise and maintain a healthy consumption of water throughout the day.