Trained endurance athletes can improve their performance by training occasional low intensive with low glycogen stores. This leads to adjustments including metabolism and cycling efficiency, which can improve endurance performance.


For optimal endurance performance athletes should ensure that their energy supply in the form of glycogen levels is high enough. The advice is therefore to ensure that prior to training and competition sufficient carbohydrates are taken.
Some researchers believe that it may be advantageous to train occasionally with a restricted carbohydrate stock. Researchers have examined the impact on endurance performance of a 3-week protocol which endurance athletes who trained two days a week with a limited carbohydrate stock.


21 well-trained triathletes participated in the study, divided into two groups. They all did the same six weeks of endurance training, and only the time of their carbohydrate intake in the last three weeks differed between the two groups.

The control group missed no meal and started each workout with a sufficiently supplemented carbohydrate stock.

The other group, “train low”, TL-group, conducted six times a highly intensive workout from 8 x 5 minutes at 85% of the  maximal aerobic power, the FTP, each time with 1 minute active recovery after a carbohydrate meal, but trained low the next morning, cycling 60 minute at 65% of FTP with a carbohydrate depleted stock.

The effects of training with low carbohydrate reserves are determined by various tests such as:

  • A submaximal test
  • A supramaximal test at 150% of the individual FTP
  • A simulated triathlon race:
  • First 40 minutes of cycling at 70% of the FTP
  • Next a 10 km race.
  • A number of blood tests.

All athletes were given the same quantity of energy and carbohydrates.

Prior to the study, the tests were first completed so that they could be compared later.

The TL group performed better after three weeks on the 10 km than before. From 40:23 to 39:50; an improvement of 3.1% .The time of the control group remained unchanged: 40:50.

The TL group improved their performance on the supramaximal test of 52.7 to 57.8 sec, while the performance of the control group did not significantly improve, 58.3 s.

During the exercise tests athletes from the TL group felt less tired after 3 weeks than before and  their heart rate was lower in a similar effort,  for the control group, however, there was no difference.

Finally, in the TL group the concentration of the hormone adrenaline increased, fat mass decreased by an average of 1 kg. In the control group, there were no changes.


Well-trained endurance athletes can improve their performance by training occasional at low intensively with a low-carbohydrate stock. This leads to changes in metabolism and may improve endurance performance.

Obviously, athletes have to ensure optimum energy supply prior to a match.