Combating fatigue while running fast is a requirement for successful running. Anaerobic Speed Reserve is the difference between an athlete’s maximum speed and their maximum aerobic speed. It has its own physiological formula and algorithms.

When an athlete is unable to complete an interval training workout within the required times, it is usual for coaches to add more reps, slow the required times down or give more rest. The theory behind this is to build more base conditioning. However, one of the main reasons that athletes fall off the pace, either during training or at the end of a race is not through lack of aerobic or anaerobic capacity or because of the need to do more distance training. The answer is often that the athlete has not developed the speed required to take maximum advantage of the energy system requirements of the distance.

Developing a speed reserve is best seen in the 400m event. This requires both anaerobic and aerobic energy systems. Most world-class 400-meter runners usually start as 100 and 200-meter runners and are very fast. Their training focuses on developing speed rather than over-distance conditioning work.

As an example, two female athletes are going to compete against each other in a 400-meter sprint. To win in New Zealand they must run around 56s.

Athlete A has a 200-metre personal best of 25.5s.

Athlete B has a 200-metre personal best of 26.0s.

Sprint manuals state that in a 400m the 1st 200m should be your best 200m + 1.5 seconds. The 2nd 200m should be your 1st 200m + 1.5 seconds. Using the above rule, each athlete’s race strategy should be as follows:

Athlete A: 1st 200m - 27s, 2nd 200m – 28.5 = Final time 55.5 seconds

Athlete B: 1st 200m – 27.5, 2nd 200m – 29 = Final time 56.5 seconds

If both athletes go through the first 200m in 27s, Athlete A is running at 94% of her best 200m pace, while Athlete B is running at 96%. During the second half of the race, Athlete A needs to run at 89% of her PR while to win, Athlete B (who is already running 2% harder) must run 91% of her best 200m. The outcome will be that Athlete A will turn a 0.5s speed advantage (over 200m) into 400m victory.

The faster athlete usually wins. In athletic track and field races the same applies to all events. To run a good 1500m you must be able to run a good 800m. To run a fast 800m you must be able to run a good 400m. To run a good 400m, you must run a fast 200m. It goes all the way down the line.

The fastest 5k and 10k runner in the world, Kenenisa Bekele, has often finished the last lap of a race in 52-53 seconds. His PB for 1500m is 3:32.35. The current Olympic Champion, Mo Farah, often finishes his races at the same 52-53s pace. His best 1500m time is 3m28.81. This time is even faster than NZs 1500m Olympic Silver Medalist, Nick Willis (3m29.60). It shows that when it comes to 5,000 and 10,000m, the fact that Mo Farah has the best speed reserve means he is going to have the biggest advantage in the longer races. Mo Farah isn’t afraid to line up against the best 1500m runners in the world. His best time shows that he is also very competitive when he does.

How do you develop speed reserve? Firstly, you need to understand the energy system demands of your event. When you start a run, there are three physiological and biochemical systems that work together in phase order: Creatine Phosphate, Anaerobic Glycolysis and Aerobic Respiration. The body’s initiation of each is dependent on the exercise time and the explosiveness demands of the event. While an explanation of these systems needs their own page, what is important is that to get the best value from these systems you need to spend time developing speed and acceleration. Research has shown that the reduction of fuel supply has no effect on speed. It is the change in running mechanics that does. If wanting to run faster, then train the body with fast, short repetitions.

Speed development takes time. It is much harder to get faster than it is to run longer. It only takes few weeks for an unfit person to be able to successfully run 20km. However, it can take many months to be able to improve 1 or 2 seconds over 200 metres. When you are faster over each progressive distance and your training program incorporates sessions that continually develop that advantage you will be able to rely on your speed reserve, once fatigue kicks in. It is your anaerobic speed reserve, not aerobic conditioning, that will make the difference.