Do we need sodium supplementation?
“Is Sodium Supplementation Necessary to Avoid Dehydration During Prolonged Exercise in the Heat?”
Martin D. Hoffman and Kristin J. Stuempfle. (2015) Is Sodium Supplementation Necessary to Avoid Dehydration During Prolonged Exercise in the Heat? The Journal of Strength and Conditioning Research, 30(3)/615-620.
Do we really need sodium supplementation?
As we exercise, we lose water weight through perspiration. It has been speculated that a loss of just 2% body weight will cause a decrease in performance leading to the increased use of sodium supplementation. This supplementation can be through sport drinks and/or sodium pills. This study looked at 233 participants in a 161 Km (100 mile) race with temperatures reaching 39°C (102°F). Participants ranged in age form 19 to 64 years of age This is a prime example of a high temperature endurance race where we would fully expect a massive loss of water and sodium.
They measured the weight of the participants during registration, and one and a half hours prior to the race. Further weigh-ins were at 48 km, 90 km, 126 km and upon completion of the race. These weigh-ins were to look at fluid loss. During an event of this nature the study calls for a 3-4% loss of weight to be considered euhydration (normal). They showed that runners who drank to thirst without sodium supplementation lost 3% of their body weight. With this the research they suggest that sodium supplementation may not be necessary.
Those using sodium supplementation never lost more than 2.5% body weight and finished the race at a loss of 1.9% from the beginning weight (overhydrated). The research saw this fact leaning to more appropriate hydration levels with those who did not intake sodium. As stated within this journal entry; athletes can safely be advised to avoid sodium supplementation during 15-30 hours of exercise.
So why is this important? Looking at these findings we need to take a step back as weekend warriors, and sports enthusiasts and possibly refrain from taking in sports drinks laden with sodium, and sugars. Our bodies do an amazing job maintaining homeostasis even in the face of highly demanding physical endeavors.
It is important to note that this study was done solely on endurance athletes, and could be extremely different for high intensity sports that place a higher demand on explosive moments and prolonged bouts of extreme exertion versus steady state exercise. This study was only based on hydration levels, and not overall performance either. This is simply food for thought, as most people do not exert themselves as much as these athletes but have no issues taking supplements when there is truly no need. One more caveat, other issues can arise from over and under hydration, which needs to be understood when competing in any physical activity leading to a large loss of water.