“A tastier, healthier, all natural sports drink” is the way most riders described Elena’s Elixir. That was exactly my intentions. Water as a rehydration liquid is always best and you should drink until your thirst is quenched. The dangers of over-hydrating though cannot be understated as every year sees the death of elite athletes from hyponatremia. The science of sports drinks is vast and covers a lot of ground including improved endurance and performance merely from tasting sweeteners in your mouth during an activity. Thankfully no one asked me if there was a diet version. Most athletes are aware that artificial sweeteners have no role in healthy nutrition.
You sweat for many reasons and the content of your sweat varies based on your gender, baseline nutrition and even your fitness level. During activity though one thing remains clear, your muscles are contracting, getting heated up and need fuel. Balancing the needs of your muscles with the needs of your blood vessels to move blood around to vital organs is a delicate balance.
There are several different types of sugars but only one can be used for fuel by muscles and that is glucose. The other sugars can get broken down into thermal energy but are not tied to insulin and electrolyte movement the way glucose is. Exploiting these differences and is what led me to choose fruit juices and honey. Fruit and honey have fructose and glucose as their main sugars. Fructose passively diffuses into cells and if the body is in negative energy balance will get consumed. Glucose requires insulin to get into cells for fuel burning but drags potassium along with it. In the process sodium gets kicked out of the cell making it available for sweat losses. The amount of sugar an athlete might want or need is variable but for the purposes of this version, I kept it deliberately on the low side. You may wish to add more based on your fitness needs but most people dislike the intense syrupy sweet nature of commercial products.
While most people think of “salt” as sodium chloride, potassium salts are underappreciated in their role for normal bodily function and muscle contraction. Excess sodium intake can precipitate high blood pressure whereas a high intake of potassium can actually lower your blood pressure. In the case of athletic exertion we need to remember that potassium is needed to help move glucose into cells and if you want to maximize performance and endurance more glucose is needed which means more potassium too. For example someone asked if they could just substitute lime juice instead of lemon if they wished. Unfortunately, ounce for ounce, lime juice has half the potassium of lemon juice. Increasing the lime juice proportionally is possible, but then a decrease in sweetener would be needed to put the ratios of potassium to glucose back in line producing an undesirably sour product. So my choice of fruit juices was deliberate based on the potassium content.
Undeniably avoidance of hyponatremia is desirable so some sodium had to be placed back into the product. During glucose movement into the cells, sodium is kicked out and then sweated out. If an athlete drinks only water and too much of it, it will dilute their blood without replacing sodium and lead to a dangerous drop in the overall sodium content of the body. All bodily functions require the presence of sodium as a shuttle across cell membranes and without it all life ceases to exist. This is not an electrolyte to trifle with. Most casual athletes will never encounter this problem for a variety of reasons. Their fitness and performance levels are not high enough; their diet has more than enough salt in it due to restaurant meals, processed foods, etc. However for those who are elite athletes or train like one, they have very different eating and exercise habits which need to be considered. Fruit juices have a highly variable sodium content but combined with the amount of salt in the recipe accounts for approximately 60% of the sodium lost in sweat (by volume) while balancing the flavor to not make it unbearably salty. This is a variable that can be calculated independently of the above two factors but careful consideration of how much sweetness one needs to mask the salty flavor will be the limiting step to how much one can add.
The ultimate goal of this experiment was to see if I could create an all-natural rehydration drink based on sound metabolic principles that people would like. I hope I succeeded. Stay tuned for future recipes with different juices to satisfy everyone’s tastes!
Dr Christofides