Hydration and Nutritional Fueling
I am always amazed at the amount of advertising and promotional work done towards children, teens, and "weekend warriors" in regards to proper hydration and nutrition. As with any health and fitness craze out there, we are constantly bombarded with slogans and creative advertisements to try and get you to buy a specific supplement or sports drink. There is even more emphasis placed on buzz words such as "electrolytes" to try and convince individuals that the product that a company is selling is the one you need to take your performance to the next level.
I am going to try and enlighten some of you here with some definitions and explanations into what exactly is needed when it comes to proper nutrition, hydration, and of course performance 'enhancers'.
Let's start off with the most important - water! Believe it or not, but water affects athletic performance more than any other nutrient. It plays a crucial role in exercise, especially when the body is sweating. Electrolytes and water have a close relationship because they regulate each other and determine the concentrations each one maintains within the body. Dehydration is a serious matter and can cause not only decreases in performance, but also unconsciousness and even death if not treated properly. Sure, we have a thirst mechanism that tells us when we are thirsty to try and maintain proper levels, but when fluid levels drop as quickly as they do during exercise, our thirst mechanism is unreliable.
Adequate water intake for a non-exercising individual is about 2.5-3.5L per day. Once you factor in sweating from exercise, fluid intake can reach as high as 11-15L for individuals sweating for many hours during a day! Below is a quick guideline that you can follow to ensure that you are meeting your hydration needs:
Before an exercise session - 0.5L (16oz), 2 hours before a workout
During exercise - 177-237mL (6-8oz) every 15 minutes.
After exercise - at least 0.5L of fluid for every pound of body weight lost during exercise.
Even with the guidelines above, I still believe that most athletes are fine competing for an hour or two without consuming any beverages - assuming that you are well-hydrated prior to exercise or competition. If you look at ultramarathoners for example, they very rarely hydrate during a race, and certainly do not take in water at the same rate they are sweating it out.
A buzz word for companies that sell sports drinks, you may be surprised just how easily the average individual can actually maintain healthy electrolyte levels! The electrolytes that play a role in exercise physiology are; sodium (fluid regulation), potassium (muscle contraction), chloride (muscle contraction), and magnesium (muscle contraction). These are the ingredients that are included in any standard sports drink.
Let's first discuss sodium. For extremely intense exercise, an individual may reach a level of around 1.8L of sweat lost within an hour, and that is being generous with the numbers. In that 1.8L of sweat, the concentration of sodium will be anywhere from 0.46-2.3g/L. To do the math for you, that works out to be anywhere from 0.828-4.14g of sodium lost in an hour of intense exercise, and that is based on a very generous 1.8L of sweat loss.
Why is this important? The average person intakes 4-6g of sodium every day. At this rate, the only time an individual would need to 'supplement' with either salty foods or a sports drink would be if they exercised in pretty intense heat for an hour or more.
Let's also look at potassium, as this is really the only other electrolyte lost through sweat. The average diet intakes approximately 2-4g a day, which is already quite adequate in maintaining positive potassium levels. If an individual is more active than not, they can be encouraged to enrich their diet with potassium-rich foods such as citrus fruits, melons, strawberries, tomatoes, bananas, potatoes, meat, and milk.
Keep in mind that the body actually experiences physiological adaptive mechanisms from more training. In other words, the healthier and more active you are, the more diluted your sweat becomes, requiring even less electrolyte replacement!
Pre and Post Exercise Nutrition
The most common recommendation is to eat 3 to 4 hours prior to exercise or competition to ensure sufficient digestion and prevent an upset stomach. I, myself, enjoy eating a carb-rich meal a few hours prior to a competition, but do not feel it is necessary to eat anything prior to my early morning workouts. Since I am exercising first thing in the morning, I will oftentimes consume a carb-rich snack with a bit of protein such as chocolate milk prior to a resistance workout, but find aerobic or intense interval training is best completed on an empty stomach. This is not for everyone, however, as many people simply find that they run out of energy before the end of their workout. In those cases, I recommend something light and carb-rich that will help top-up your glycogen stores such as a half or whole banana.
Following intense exercise or competition, I still stand by the need for nutritional intake within 60-90 minutes. One key thing here though, the exercise must be intense! Also keep in mind that one of the main reasons for post-workout nutrition is to re-fuel your body for your next workout. I like the 3:1 or 4:1 ratio of carbs to protein in a post workout drink or meal. This allows the body to top-up depleted glycogen stores, but also promote muscle fiber growth and repair.
Having said all of that, I find many people vastly overestimate the amount of calories that they actually burn within an hour. For the average person, you are generally looking at anywhere from 400-800 calories burned in an hour of exercise, with numbers reaching the low 1000's on rare occasions. Research has shown that to prevent a decrease in performance from one workout or competition to the next, an individual should not allow their daily caloric deficit to drop below 400 calories per day. So for example, if an individual is looking to lose weight, but they wish to maintain their performance gains, and burn 700 calories in an hour of exercise, then they should consume an additional 300 calories for that day.
As with any product on the market today, companies will do what they need to do in order for you to consume their product. In many cases, this results in products being marketed towards individuals that do not actually need them. For example, sports drinks are a perfect example of this. They lead you to believe that you need to 'replenish your electrolytes' when in fact, if you lead a healthy lifestyle with a well-rounded diet, you do not need additional supplementation in that regard. In many cases, these various sports drinks offer unneeded calories, especially for individuals looking to lose weight!
When it comes to hydration, the more fit you are, the more well-rounded your diet is, and the more hydrated you stay at times apart from exercise will determine your success. You rarely see serious competitors in endurance events carrying water bottle belts with them. Cyclists will sometimes have a small bottle of water with them, but certainly not intended to replace the amount of fluid loss during competition.
When it comes to sports drinks. You may see a professional athlete enjoying some sugary drink, but that is to help them maintain their anaerobic power for the multiple hour-long game. These beverages really are not needed for the weekend warriors amongst us, despite what companies will have you believe!
I will look into and write a blog in the coming weeks explaining why I feel pre-workout 'energy' drinks are also grouped in this same category of clever marketing. Stay tuned!
Baechle, Thomas R. and Earle, Roger W. Essentials of Strength Training and Conditioning Third Edition