Within the muscles there is a store of high-energy chemical compounds which enable these muscles to contract. The first substance is Adenosine TriPhosphate or ATP and the second is Creatine Phosphate or, in short, CP.
During muscular activity this Adenosine triphosphate turns into Adenosine diphosphate, thus supplying the muscle with energy.

Schematically: ATP → ADP + energy

Creatine phosphate is capable of forming ATP out of ADP very rapidly.

Schematically: ADP + CP → ATP + Creatine

Features phosphate battery:

The quantities of ATP and CP within the muscle cell are limited.
The total store of ATP and CP is exhausted after 6 to 8 seconds of maximum effort.
The phosphate battery does not need oxygen and there is no formation of lactate.
The energy generated by this system is ready for direct use.
This system in important for short, highly intensive energy boosts.
In cycling, a well-trained phosphate battery is decisive for either winning or losing.


The process of resynthesizing the high-energy compounds (ATP and CP) is also very fast. After depletion the store of ATP and CP is replenished after several minutes after stopping the effort. This process is over for 70% after 30 seconds and it takes 3 – 5 minutes to fill the store up to 100% again.

The phosphate system is trained by short power boosts, alternated by recovery periods. These recovery periods should be long enough, after all rebuilding the phosphate battery takes some time.

Daphne Schippers, world champion 200 meter
The supply of ATP and CP will be exhausted after a short, fast sprint. During the recovery period this supply is fully replenished after a few minutes. After 30 seconds this recharging is completed for 70% and after 3 to 5 minutes it is near to 100%.


By a combination of endurance and sprint training workouts an increase of ATP and CP will come about. The sprint workouts bring about an increase of those enzymes that break down and build up ATP, thus making a faster breakdown of ATP possible which means faster energy. Through this specific training programme the store of ATP and CP will be increased and in addition the breakdown and build-up processes are accelerated.

Sprinting at maximum speed will exhaust the supply of high-energy phosphates after only a few seconds. Sprinting capacity can best be trained through interval workouts with a great number of repetitions. In fact a sprint workout is not really an interval workout because recovery is near to complete rest. The intensity of the sprints may be maximal or sub maximal. At maximum speed the sprint may last 6-8 seconds, at sub maximal speed it may last up to 20 seconds. The essential point is complete depletion of the store of high energy phosphate without accumulation of lactate. In cycling it takes several seconds to reach maximum speed when starting from zero. It is of great importance that the recovery period between two sprints is long enough. On the one hand because recharging the high energy phosphates, ATP and CP, takes some time, on the other hand to avoid calling in the lactate system. The duration of the recovery period is 3-5 minutes, but it may well be longer.

During interval workouts the store of ATP-CP is largely replenished during the recovery periods. Top line: better recharging of the ATP-CP store through complete recovery. Bottom line: recharging ATP-CP through incomplete recovery, i.e. light exercise.

In ideal circumstances no exercise at all is done during the recovery periods, in absolute rest there is a faster recharging of the supply of ATP-CP. Even very light exercise slows down the resynthesis of ATP-CP. This results in calling upon the lactate system for the next sprint which cannot be the intention of this workout.
Phosphate training cannot be guided or corrected by heart rate registration. Measuring lactate may be used to show that lactate concentration must not run up too high.