The concept of train low-compete high has been very popular over the last few years and has been adopted by many elite athletes. This strategy involves training with low energy reserves (glycogen depleted state) and competing with high energy reserves (glycogen loaded).
It has been known for a long time that carbohydrate loading results in an increased amount of stored energy thereby increasing time to fatigue during endurance exercise lasting longer than 90 minutes. It would therefore be easy to think that training and competing glycogen-loaded would be a good idea. However, recent evidence shows it may be more beneficial to train in a glycogen depleted state to boost substrate metabolism and stimulate the muscular adaptation to training. The overall effect is that we become more effective at burning fat as an energy source thereby sparing muscle glycogen stores and possibly increasing time to fatigue.
What type of athletes might benefit?
Endurance and ultra-endurance athletes may benefit due to the lower training intensity where reliance on fat as a fuel source would help spare muscle glycogen stores and theoretically, improve performance. The higher the intensity of exercise, the greater the reliance on carbohydrates as an energy source. Therefore, this strategy may not be as effective with team sports players or power athletes.
Research in this area is still ongoing and it is therefore recommended that a balance between low and high glycogen training is followed. Suggested strategies are as follows:
No pain no gain!
If you’ve ever tried to train with insufficient energy supplies before you’ll be very familiar with the feeling of heavy legs and general discomfort over and above what you’d normally expect. This feeling is associated with glycogen depletion and a lack of available energy resulting in an increased perception of effort. Your brain is basically trying to tell your body to slow down and stop exercising. It is possible to overcome some of these feelings with the use of caffeine before the session. Caffeine has repeatedly been shown to improve endurance exercise performance and reduce exercise induced discomfort. Try consuming 1-3mg per kilogram of body weight (70kg athlete = 70-210mg) or 2-3 cups of coffee, 1 hour before exercise.
Training in a glycogen depleted state increases an athlete’s ability to utilize fat as an energy source. In endurance events this may spare muscle glycogen and improve performance. However, in strength events, team sports and endurance events lasting less than 1 hour, there is no performance benefit to training in a glycogen depleted state.