In search of the 70 kph human: challenging the limits of human muscle contraction time, a pilot investigation

Abstract

ORIGINAL RESEARCHwith the remarkable performances of Usain Bolt in the 100-m sprint, people are speculating about the capacity of humans to run faster. Interest from the population at large with regards to these incredible performances have led some scientist's to propose, through media, that they are attributable to the existence of the super fast-twitch fiber in fast humans (1); which in the absence of published scientific data remains unproven. According to other scientists the faster runners produce more vertical force instead of repositioning their legs faster (2) but humans can already produce 30% more average and 16% more peak vertical force when hopping than they currently choose to use in a maximal sprint which should mean that humans are capable of running much faster already; between 50-and 70 kph (3). Science is now debating whether human sprint performance is instead limited by the capacity to produce force in the smaller and smaller ground contact times as speed increases; as faster muscle fibers would permit the limbs to apply greater forces (3). Without any scientific proof to date of super fast-twitch fiber with distinct properties in humans, maybe the fastest sprinters simply have fast-twitch fiber that has adapted to contract slightly faster through specific training.In the animal kingdom, super fast muscle powers high-frequency sound production and visual tracking which requires low forces (4) but in human sprinters, if the super fast fiber Interest in sprint running has been fueled by the remarkable performance in 100-and 200-metre events at the 2008 Olympic Games. Amid this interest, speculation mounts as to how fast humans can run and to the existence of new types of fast-twitch fibers as the mechanism that realizes faster performances. This paper adopts the view that humans are limited in how fast they can run by how much force they can apply within the muscle contraction times inherent of fast running and proposes a method by which adaptation may be forthcoming to strengthen the locomotive muscles in humans within that required contraction time or shorter contraction times. The proposed method consists of the fast foot drill exercise executed with the intent of increasing the rate of stepping; training with this method was carried out over 16 weeks. The analysis of the post-training stepping rate shows that movement frequencies in human locomotive muscle approaches 7 muscle contractions per second. The analysis also shows that muscle activation times approach 90 milliseconds for the vastus lateralis muscle and 55 milliseconds for the biceps femoris muscle. Furthermore it is speculated that as a result of this training method muscle contraction times may approach and surpass the time limits for humans that are currently accepted in science. The hypothesis is that by combining the fast foot drill with progressive external resistance, runners can increase their force production within the ground contact time inherent of fast running that currently limits how fast humans can run.

The multi-functional foot in athletic movement: extraordinary feats by our extraordinary feet

“…Similarly, during running, impacts of multiple times bodyweight are comfortably accommodated, by runners of all abilities, for little discernible effort. In elite sprinters very forceful ground contacts must be managed in windows of as little as 80 ms -1 [2]. In non-elite marathon runners, impacts, while less forceful than those of the sprinter, nevertheless typically number beyond 21 thousand contacts, again of multiple times bodyweight per leg [3].…”