Have you ever “hit the wall”? Experienced that awful feeling of going from feeling great to feeling awful and just not being able to move forward? There are a few key factors that contribute to “hitting the wall”, and not being properly hydrated is one of them. Entering any competition in a dehydrated condition is a huge mistake.
The importance of hydration
It is simple: If you're not properly hydrated, your body can't perform at its best ...
Daily water needs vary substantially, based on factors such as body size, physical activity level, and the local climate. It used to be a general rule that an adult should drink eight 8-oz glasses of water per day. But, it is now known that these levels are inadequate, especially for very active adults. Adults need about 2-3 litres (9-12 glasses) of water per day to maintain healthy hydration levels. And when you are active, the needs increase to replace fluids lost through sweating.
The role of fluids
Water is essential for life. Among its many roles, it maintains blood volume, regulates body temperature, carries nutrients around the body in the blood, helps chemical reactions in our body take place, and helps to get rid of waste products through urine.
During exercise, the body cools itself by sweating but this ultimately leads to a loss of body fluid which, if not replaced, can lead to dehydration. Sweat production (fluid loss) increases with higher temperatures and humidity, as well as with an increase in exercise intensity.
Dehydration and sports performance
Dehydration can have a serious detrimental effect on your sports performance. An athlete who loses more than two to three percent of body weight during exercise may be at a point of compromising performance and physiological function. Losses in excess of 5% of body weight can decrease athletic performance by about 30%.
Endurance athletes are often thought to be most affected due to fluid loss through sweating, however, athletes who travel to compete in hot climates are also at risk. The capacity to perform high-intensity exercise, which results in exhaustion within a few minutes, is reduced by as much as 45% by prior dehydration of as little as 2.5% of body weight. Acute dehydration can persist for several days and may be serious enough to have a detrimental effect on performance in competition.
Signs of dehydration
Many people don’t recognise the signs of dehydration. These may include: • dark urine • small volume of urine excreted • headaches • tiredness and lack of concentration. Thirst alone is not a very good indicator that you should drink water, as your body is already dehydrated when it sends a thirst signal.
How Much Fluid & When?
Drinking fluids (the right kinds of fluid) during exercise will help to prevent a drop in performance caused by dehydration. Drinking fluids after exercise re-hydrates you. But it is important to be well hydrated before you even start to exercise. Here are some tips:
- Always start exercise well hydrated: this will lower your risk of becoming dehydrated during exercise. But - there is minimal benefit to being over-hydrated as drinking excessive amounts of fluid before exercise causes increased urination and gastrointestinal upset.
- Develop a plan for drinking during exercise based on your sweat rates (see below).
- Follow the strategy described in Sweat Production (below) to ensure adequate replacement of fluids after exercise.
- Different sports pose different challenges and opportunities for optimal hydration. For team and racquet sports there are formal breaks between play, with substitutions and time-outs, all offering an opportunity to drink. Some individual sports require you to drink on the move. Be smart and practice strategies to get maximum benefit from fluid intake with minimal fuss and discomfort. Try special squeeze bottles, or hands free drink pouches if practical.
- Thirst is not an effective indicator of hydration levels while exercising. Feeling thirsty is an indication that you are already dehydrated.Did you know…Your weight change immediately after exercise can indicate the amount of fluids that need to be replaced.
Did you know: Your weight change immediately after exercise can indicate the amount of fluids that need to be replaced.
Weighing yourself before and immediately after activity is a good way to measure the amount of fluid lost during exercise. If you are lighter after an activity, then it is likely that a fluid deficit has occurred and you will need to replace those lost fluids. This fluid deficit also indicates the amount to increase your fluid intake during the next practice. The chart below provides some basic guidelines to follow:
Can you drink too much? If you gain weight after an activity, then you may be over-hydrating. In cool weather or when your exercise intensity is low, sweat losses may be small. Drinking more water than necessary has the potential to interfere with performance (and can be dangerous to health) in several ways. Over-hydration during exercise is called hyponatremia (very low levels of sodium in the bloodstream). Symptoms include headaches, disorientation and in severe cases, coma or death. It is important to note though that this is relatively rare and dehydration is a typically a more common issue for athletes. By monitoring your fluids before, during and after exercise, you will help to ensure proper hydration in any circumstance.
The best type of fluids for hydration
For lower intensity exercise sessions, water is often sufficient for replacing any fluid loss. However, intense exercise causes your body to lose nutrients as well. These nutrients (aka electrolytes, minerals such as calcium, magnesium, sodium and potassium) need to be replenished. Under normal circumstances, these nutrients can be provided by eating a balanced diet, but intense exercise causes us to sweat, and when we sweat, we lose electrolytes.
Sports drinks contain electrolytes…but commercial sports drinks often contain added sweeteners, preservatives and can be expensive. There are homemade or DIY options, such as Lemon-lime Refresh or Citrus Green Recharge. Coconut water itself also serves as a great sports drink, containing more potassium than sports drinks (13x more than Gatorade) and natural sources of sodium. Stay tuned for a future blog on this subject.
Bottom line? Hydration is as important as any other element of your diet, and requires as much attention. Fluid needs are highly individualised and there’s no ‘one size fits all’ approach to fluid intake.
Interested in learning more about hydration and other aspects of sports nutrition? Contact Active Nutrition for a 15 minute sports nutrition consultation to learn how I can help you.