Many people drink sports drinks before or after exercising. These often contain a lot of carbohydrates (Gatorade = 30 grams, Powerade = 25 grams) which are being shown is scientific studies to work against your exercise efforts. Here is an interesting paper that reviews the benefits of ketogenic diet. Its an interesting read with some great historical perspective.
Here is the low down.
Low glycemic foods (food or drink with no simple sugars and mainly starches) consumed before exercise consistently:
- Improves the body’s ability to burn fat as an energy source.
- Decreases the body’s reliance on glucose on fuel.
- Spares muscle and liver glycogen stores (more to use during exercise)
- Increases the liver’s ability to produce glucose later in exercise a athlete’s become more fatigued.
- Improves performance.
After exercise its best to have no carbs because it will prolong fat burning. If you want something sweet after exercise, it needs to be a low glycemic index (GI) drink like Powerade Zero or Gatorade G2.
Low glycemic foods consumed after exercise:
- Low GI carbs prevent rebound low blood sugar and rebound hunger.
- Low carb/low GI prolongs fat burning with lower insulin levels
- High carb/High GI seem to eliminate the insulin resistance reducing benefits of exercise.
The concept of “carb loading” as a way to improve athletic performance comes from studies originally done many decades ago. Athletes were found to perform better after consuming carbohydrates, not only the night before but especially during an athletic event.
Additional studies since have shown that the body doesn’t really need any help loading up the muscle with glycogen (muscle sugar) and consuming sugary drinks during an athletic event may actually worsen performance.
In regards to eating carbohydrates the night before an athletic event (classic carb loading), this does nothing to promote greater glycogen storage. The body can only store so much within the muscle and can achieve this within a few hours even when fasting.
And interestingly, although sugary drinks consumed during an event seem to improve athletic performance, the improvement has nothing to do with providing the body more sugar as fuel. It seems we have “sweet sensors” in our mouths that are activated by the sweet drink in our mouths. These receptors stimulate a portion of our brain that stimulates the athlete psychological drive or intensity. This is true mechanism how sugary substances during and event improve performance.
So remember, the improved performance although real, has nothing to do with the addition of more sugar as fuel. In fact, athletes performed better if they rinsed their mouths with a sweet solution every 10 minutes or so and then spit out the solution rather than drink it.
You gotta love science!
My advice is to keep it simple. Focus on minimizing the carbohydrate in the diet to maximize fat burning and just drink cool, clean water before and after working out. The average athlete really doesn’t need the added sugars to maintain their performance.