In anaerobic metabolic processes the body needs as much energy as possible for a short period of time and this cannot be covered by the aerobic energy supply. The utilization of the energy reserves is then carried out by providing energy without oxygen. However, this energy supply is already used up after eight to ten seconds.
To replenish these reserves, the body needs creatine phosphate, which is sufficient for another twenty seconds. A large part of the physical performance (more than 90%) is achieved aerobically. This means that energy is provided with the participation of oxygen.
Only a small proportion of the energy supply (maximum 10%) is provided anaerobically without oxygen. One could now assume that this 10% does not play a major role in an endurance run or a 5 km race. A large-scale study was then carried out to determine which factors are the most important in a 5 km race.
Contrary to all expectations, aerobic performance was not the decisive factor. Rather, in addition to the time to exhaustion (TTE), the anaerobic performance was decisive. The better the anaerobic performance of an athlete, the better the 5 km time was.
This becomes clear especially at the end of the race, when the athletes run as fast as possible again and mobilize the last energy reserves, the energy is provided almost exclusively by anaerobic means. An advantage of a higher training level is particularly evident in this part of the race. Not everywhere is so much emphasis placed on anaerobic endurance performance as in the middle distance.
Especially middle distance athletes should take care to develop the anaerobic system well. Anaerobic training should only be done to a certain extent, as too much anaerobic training can have a one-sided training effect. You lose muscle fibres that are important for slow endurance movements and then train your fast contracting muscle fibres that are important for sprinting. Especially in running, anaerobic training is used to train the competition-specific endurance that decides on victory or defeat. Since the intensity of such training is around 90% of the maximum heart rate, too much training in the high range can overstrain and also damage the cells.
Interval training 1
There are different approaches to training the anaerobic threshold. The 1000m intervals are a variant of how anaerobic threshold training can look like. If we assume an athlete who runs 50 km per week, then we should spend 10% of the weekly mileage for 1000m intervals.
In this case, you would have five kilometres, or five times 1000m intervals per training session. After the warm-up you start with the first three 1000m intervals. These are done at the same race pace as a 5 km run.
The recovery breaks between the intervals can be just as long or slightly shorter than the stress phases. The last two intervals of the training session are divided. The first 600 metres of each interval are completed at race speed, as for the first three kilometres, and the subsequent 400 metres are completed a few seconds faster than race speed. This gives you 800 meters per training session, which are completed in the anaerobic range and can shift the anaerobic threshold. The break between the last two intervals can be a bit longer than the previous ones due to the higher load.