Why must we increase power reserve to run faster in the marathon?
In order to progress quickly and above all, in a sustainable way, rely on a training strategy that consists of increasing the limits of your power reserve. Think of your power reserve as the ability to increase your running speed. Oxygen consumption (VO2max) in our cells is the primary reason limiting our running speed. We all have a limited VO2 max for many reasons; muscle strength is a major limiting factor in running faster. Weak musculature limits your speed and ultimately leads to an early withdrawal from the marathon without having reached your true maximum heart rate, your maximum intramuscular oxidation, and optimal turnover of lactic acid in your muscles. In order to improve your metabolism, it must be done by developing optimal power in both 10 and 30 second intervals. Currently, most coaches prescribe training for marathons to be done “at the anaerobic threshold. ” We will clarify the real meaning of anaerobic threshold, or at most to MAS (which we will also reveal the true meaning and especially its limitations).
MAS = Maximum Aerobic Threshold
It is preferable to have a large reserve of power rather than trying to maintain a high percentage of your MAS by being so-called “enduring.” This will save you unnecessary miles and its consequences in terms of chronic fatigue and injuries. We like to think of increasing your speed reserve in terms of the average marathon speed and your maximum sprint speed. For example, if your average marathon speed is 15 km/hr (2h48min pace) and your maximum sprint speed is 30km/hr, then your speed reserve would be equal to 15/30, which is 50% of your maximum sprint speed. We often see around 60% or greater of maximum sprint speed, which would be about 25 km/hr. Moreover, by increasing your speed reserve between your marathon speed (15 km/hr) and your maximum sprint speed (30 km.h-1), you will be, at an absolute speed equal to 15 / 30 = 50% of your maximum sprint speed rather than 15/25 = 60%. This will result in less neuromuscular fatigue and improve the utilization of creatine phosphate. This intramuscular super fuel allows you to have short spurts of energy and a strong support for a better recoil of your elastic energy during each stride.
It is important to realize that during a marathon at a speed of 15 km.h-1, a runner takes 27,178 steps (Table 12). 42195 / (15000/3600 × 2.66) = 27178 steps since the distance of a marathon is exactly 42,195, 15000/3600 is the calculation of the speed for a marathon time of 2h48min. The frequency of steps per second is 2.66, which is written in Hertz. This corresponds to a stride frequency which is generally indicated on your watch as the number of strides (2 steps) per minute. Equaling 60 × (2,66 / 2) ≈ 80 strides per minute, which is the stride frequency. Table 12. Details of step count calculations on the marathon. These calculations will motivate you to gain a shorter and more dynamic stride by increasing your speed and maximum power through acceleration training on all race times from 10 seconds to 3 minutes. In addition to having enough power to withstand the muscular fatigue of a marathon, you will also avoid the deterioration of the quality of your foot strike. We define a good quality foot strike as a short pulse time preserved beyond the 30th km. The power reserve will allow you to endure a fast start and then decelerate, making small variations of speeds below the average speed and finally, accelerating in the last 10 minutes of your marathon. By doing this, you can finish with a higher average speed, and better than that of running at an unbearable constant speed. For a good example of this, refer to figure 23 for the simulation of the sub-2 marathon. Indeed, let’s insist once again that you need a speed reserve between your marathon speed (speed zone inducing a feeling of “average” pace) and the maximum sprint speed.