Hydrating for Performance
Why is fluid important?
Our bodies are made up of 50-70% water – it is found in every single cell. In particular, our bodies need water to:
transport nutrients in the blood
bring about chemical reactions (ie: digestion)
lubricate our joints
regulate our temperature
replace fluid lost through sweating and breathing
remove waste via the urine.
Why is fluid important during exercise?
During exercise, our body uses water to regulate its temperature (via sweating), transport oxygen around the body (via the blood) and keep our joints lubricated.
Dehydration and performance
Our performance can be negatively impacted even if we’re only mildly dehydrated. The reasons for this are multifactorial:
our body finds it more difficult to thermoregulate
our heart beats harder and faster in an effort to thermoregulate, which means energy is shuttled away from the working muscles
this can make your limbs feel slow and heavy; exercise can feel more difficult and fatigue can come on faster, which impacts concentration, agility and decision making.
Not ideal scenarios in the sports arena!
Can I drink too much fluid?
Absolutely. Some athletes have a propensity to over-hydrate, which can also impair performance – and be quite dangerous. A full belly of fluid sloshing about is definitely not comfortable during exercise, and on a more serious note over-hydration can dilute electrolytes in our blood causing serious side-effects such as headaches, disorientation and in very severe cases, coma or death. This is quite rare, and dehydration is a much more common occurrence, however it supports the importance of working with a qualified dietitian to ensure you have a personalised hydration strategy if you are regularly training.
How much fluid should I drink?
The amount of fluid you drink will depend on your individual needs. As mentioned, if you are serious about your sport, you should consult a qualified sports dietitian who can assist you with calculating your sweat losses and help you devise a hydration plan.
Before Exercise
It is important to start exercise in a hydrated state. An easy way to gauge this is to check the colour of your urine. If your urine is a light-yellow colour, you are most likely hydrated. If your urine is darker, you’ll need to immediately start sipping on fluids leading up to your exercise session. Between 200-400ml is a good amount that will improve your hydration status without causing bloating or heaviness.
During Exercise
During exercise, try to take a few sips from your water bottle every 15 minutes. This keep you relatively hydrated but shouldn’t be too much to cause multiple toilet visits and/or an upset stomach. Saying this however, the level of competition, sport, and individual requirements may require different strategies and an individualised hydration plan may be needed.
After Exercise
The goal after exercise is to replace lost fluids and electrolytes. This is especially important if you have a second training session within 24-hours because we want you to enter this second session fully hydrated.
A simple way to ensure you drink enough fluid after exercise is to weigh yourself before and after your exercise session. If you weigh less after your session compared to before, multiply the difference by 150%. This is the amount of fluid you need to drink over the next 4-6 hours to replace the fluid you lost during exercise.
In regard to electrolyte replacement, try to drink fluids alongside recovery snacks such as bread, cereal or muesli bars. These foods contain sodium (salt) so they will help your body rehydrate more effectively.
What are the best fluids to drink?
For short duration sessions and/or low intensity exercise, water is the best fluid option before, during and after exercise. If you’re exercising for more than 90 minutes and/or in hot/humid conditions, sports drinks may be a better option due to their carbohydrate concentration and electrolyte balance – both of which helping the body rehydrate more efficiently.
Two beverages to be avoided around exercise are alcohol and energy drinks. Alcohol is a diuretic (causing us to lose more water) and energy drinks are too high in carbohydrates, which can cause stomach discomfort.
If you love the caffeine boost of an energy drink, try drinking coffee instead. The caffeine from energy drinks results in intense changes in heart rate and blood pressure, which could have serious consequences on performance and health. It is thought these profound changes could be due to additional stimulants in energy drinks.
Take home tips
While many of us fitness-freaks focus intently on our training and nutrition, it is imperative we don’t forget about hydration. Carrying a water bottle around with you throughout the day is one of the simplest and most effective ways to stay hydrated. Remind yourself to take a swig of water every hour by setting alarms on your phone. Or maybe drink a glass of water before every meal and snack. Another visual reminder is to place multiple elastic bands around your water bottle and only remove one each time you refill the bottle. It might sound kooky to begin with, but your body really will thank you for it!
