Hydrating for optimal sports performance
For years there has been a debate surrounding an individual’s recommended daily water intake. There have been numerous suggestions of what the correct amount should be but there are a lot of factors coming into play, which would be very individualised for each person. We should be drinking water for various health reasons but for you as an athlete hydration is even more important. Dehydration can negatively affect your performance and here is why.
Various studies have suggested that a mere 2% reduction in fluids can potentially result in a 10% to 20% degradation in performance which could affect concentration, stamina and cause cramping for example and highlight the importance of staying hydrated. Many of you may be thinking that you taking your bottle of water with you to the gym to drink mid workout would be enough but often by this point you could be on the back foot because of not drinking enough water prior to your workout. Being dehydrated even prior to exercising can result in your core temperature to rise faster and your heart having to work harder. In general, you are most dehydrated when you first wake up in the morning. Often, people’s go to drink is a caffeinated drink such as coffee prior to work. Caffeine is often being considered as a diuretic, meaning it could cause the body to lose fluids therefore, why not also drink water to help set you up for the day ahead.
However if you continue to neglect hydration prior and even during exercise you will experience a drop in your level of performance. As previously mentioned, your heart will have to work harder which is experienced because of a reduced maximal cardiac output (i.e., the highest pumping capacity of the heart that can be achieved during exercise). This is the most likely physiologic mechanism whereby dehydration decreases a person’s VO2max and impairs work capacity in fatiguing exercise (Sport Nutrition, Second Edition).
Dehydration causes a fall in plasma volume both at rest and during exercise, and a decreased blood volume increases blood thickness (viscosity), lowers central venous pressure, and reduces venous return of blood to the heart. During maximal exercise, these changes can decrease the filling of the heart during diastole (the phase of the cardiac cycle when the heart is relaxed and is filling with blood before the next contraction), hence, reducing stroke volume and cardiac output (Sport Nutrition, Second Edition).
As a result, without proper hydration it is easy to see how the lack of water can quickly reduce your performance level and that it is important to always monitor your hydration levels which can be done through a simple urine test where looking at the colour of your urine will give you an indication of your hydration levels. If the urine is dark and yellow in colour the likeliness is that you are dehydrated or close to it whereas, if it is almost clear in colour you are on the right track and should look to maintain this especially when partaking in physical activity.