For decades, sports nutrition companies that sell sports drinks, gels, and energy bars have spent billions of marketing dollars telling consumers that their products can provide fuel for energy to perform.
While the content and ingredients of these products vary by product, one common ingredient is prevalent, often in large quantities--added sugar.
But how much sugar do athletes and generally active individuals actually need? And what happens when individuals consume too much sugar?
Sugar and other natural or artificial sweeteners are the common ingredient used by sports nutrition brands to boost glucose levels in the body. Glucose is a form of carbohydrate used by the body to supply cells with energy.
However, because glucose storage in the body is very limited, when added glucose isn't needed to replenish normalized glucose levels, the body stores the the excess supply in the body as fat.
While rates of glycogen utilization vary by body mass and intensity of activity, general guidelines suggest carbohydrate utilization in the range of 2-3 grams per minute for high intensity running or cycling. At lower intensities, most individuals are “burning” carbohydrates at 1-2 grams per minute.
Therefore for exercise lasting longer than 1:30-2:00 hours, proper carbohydrate and glycogen replacement are crucial for maintaining performance.
Glycogen, the storage form of glucose, is in very limited supply within the human body. According to studies, glycogen storage capacity in muscles and liver is limited to about 400-500 grams (or approximately 1lb).
Since our body's glycogen storage capacity is so limited, many endurance athletes may find it difficult to maintain sufficient carbohydrate intake during high intensity workouts of longer duration.
However, most fitness-minded or active individuals do not fall into this category. For most exercise under 90 minutes, glycogen stores should be sufficient. When glucose enters the body and cannot be used for energy, the body stores it as fat.
Sports drinks, gels, and energy bars are everywhere today. They are being consumed in the workplace, at home, and in the car as well as before, during, and after exercise.
The problem with most nutrition products today is that they are often being consumed on an everyday basis, not for the purposes they are intended to serve (glucose replacement during extended periods of exercise).
It is well documented that a diet high in sugars has been linked to obesity and significantly higher rates of heart disease. The average American consumes around 22 teaspoons or 88 grams of added sugar every day. Both the World Health Organization (WHO) and the American Heart Associations (AHA) suggest the recommended daily sugar intake should be only a fraction of that.
The American Heart Association recommends limits for adult women of 5 teaspoons (or 20 grams) per day. Adult men 9 teaspoons (or 36 grams) of sugar per day, while children are recommended just 3 teaspoons (or 12 grams).
To put this in perspective:
Excess fat stores not only lead to obesity, but have been show to increase the risk of diabetes in children and adults. Once the fatty acids begin to spill over into your organs, like the heart, liver, and kidneys, the organs ability to perform diminishes which raises blood pressure, decreases metabolism, and weakens the body's immune system.
GI-distress is a common occurrence among athletes, including endurance athletes such as runners, who rely on sugar-heavy sports and energy formulas for hydration and carbohydrate replacement.
Sugar is a frequent cause of GI-distress because the sugar needs to be broken down by the digestive system. Studies indicate that gastric emptying and intestinal fluid absorption are reduced when carbohydrate concentration in test solutions increase above 6%, increasing risk of gut complaints.
A study by Shi et al 2004 found an increase in carbohydrate solution and osmolality provoked stomach upset and side ache during intermittent, high intensity exercise (76%). The exercise involved running, hopping, jumping, sprinting and shuttle runs.
As we highlighted previously, not all athletes or active individuals need carbohydrate (glucose) replacement drinks or products during exercise. However most exercise will result in the need for fluids and electrolyte replenishment.
Exercise results in the loss of fluids and essential minerals through perspiration, normal bowel and urinary elimination, and breathing. Failure to hydrate appropriately during exercise is the main contributing factor to poor performance during endurance events, particularly in hot and humid conditions. Athletes can find simple ways to calculate hydration needs through various online resources.
According to Sawka and colleagues (2007), the hydration goal during exercise is to prevent excessive water loss and disparities in electrolyte balance in the working muscle cells. Hydration recommendations during exercise can vary depending on a number of factors including a person's sweat rate, exercise duration, weather conditions, and exercise intensity.
Even with mild exercise such as walking or hiking can lead to dehydration, where heart rate increases and oxygen delivery to the muscles can decline up to 10%.
Just a 2% decline in body weight from dehydration will impact the body's heat regulation. With a 3% decline in body weight, there is a decline in muscle cell contraction times. And a 4% decline can result in a 5-10% decrease in overall performance which can last up to 4 hours.
When we perspire and excrete fluids from our body, dissolved in these fluids are are electrolytes and essential minerals. Mineral replacement is essential to helping provide the necessary for enzymatic reactions that restore blood flow and reduce heart rate. Without these minerals, the quality of performance during long-term or explosive short-term exercise decreases.
While it's important for athletes and active individuals to be aware of the importance of minerals for rehydrating during activities, its equally important to be aware of the type of hydration products you consume regularly.
Many sports nutrition products contain both carbohydrates (glucose) and electrolytes, but as we pointed out the timing and needs of these two factors differs for athletes.
Hydrating with water and natural minerals before, during, or after exercise or activities will help replace fluids and essential minerals necessary to restore blood volume and pH and reduce the risk and impact of dehydration.
For most athletes and active individuals, hydration is something that needs to be addressed, while glucose replenishment is necessary primarily with extended duration activities.
Hydrate by adding a healthy, balanced blend of natural minerals in your fluids, and eliminate excessive sugars and artificial ingredients that are prevalent in most sports drinks and gels on the market today.