Hydration For Swimming Athletes
Swimming: A Unique Sport?
Swimming truly is a unique sport. In obvious ways, what other sports are you horizontal for most of the event? Where the shoulders are large contributors to movement? Travel through a fluid considerably denser than air? Not many. Swimming offers unique challenges to athletic development in another way as training on dry land is notoriously difficult to transfer into the water, it is largely down to the individual athletes who skill and feel for the water. The better their transfer into the water, the less overall work will need to be completed to achieve improvement in race times. For example, an athlete who can apply 90% of lower body force production and power output into their Breaststroke kick won’t need to lift as heavy as an athlete who can only apply 50%.
What About Hydration?
So, swimming is pretty unique. But there are more ways in which swimming differs from other sports and that included hydration. Hydration and its importance to athletic performance are well established in the literature. The more an athlete allows themselves to lose fluids the less efficient their body is able to produce high-performance efforts.
It’s key to consume water during training and implement rehydration strategies after training, Milkshakes are perfect.
When one participates in sports, or exercise in general, the body stops or reduces the number of fluids lost through urine, meaning you save more fluids for thermoregulation (cooling down) via sweating and respiration. This process is primarily caused by an increase in Anti-Diuretic Hormone (ADH) and Aldosterone. ADH decreases fluid loss from urination while Aldosterone increases the reabsorption of ions and water in the Kidneys.
Hydration During Swimming
During swimming, there is a suppression of ADH and a reduction in the perception of thirst. Hydrostatic pressure on the body both expands plasma volume and suppresses peripheral blood pooling. When swimming in warm water the hydrostatic pressure also inhibits sweat gland activity, this is like to due to the faster rate of heat transfers from conduction and convection from the skin to the water. Sweating has been observed at a reduced rate during swimming studies. This coupled with observations that 1 hour of water immersion can result in 400ml of water absorbed through the skin can result in Hypervolemia, excessive fluid volume in the blood.
This results in the increased excretion of diluted urine, therefore if athletes are using urine colour as a sigh of hydration both during and after swimming training this can lead to a false perception of hydration as the diluted urine will not reflect the athlete’s true status. Over a pool training session, urine osmolality has been shown to decrease (a marker of hydration) without changes in body mass. If body mass remains constant it can be expected that markers of hydration also remain constant resulting in a fluid balance however the reality does not appear to reflect this expectation.
Research recommends that changes in body mass should be used instead, however, this also leads to issues such as wet hair may lead to false increases in body mass.