Running power and efficiency: how to improve the performance with SKILLRUN

When it comes to innovation and training methodology, we have to recognise that Technogym's scientific department is pioneering, revolutionary and, above all, solid.

Appointments that Technogym will not miss, and this year Francesco Cuzzolin and Silvano Zanuso, respectively Director of the Research and Innovation Department and Scientific research & communication Manager at Technogym, spoke about running.
Introducing first the most important aspects of the biomechanics and physiology of running, then the concept of power of running and how to monitor, train and test it with SKILLRUN, the new treadmill introduced by Technogym.

How humans move

The two basic gaits used by humans are walking and running.
They can be represented using two basic models: the inverted pendulum for walking and the bouncing pogo stick or the spring for running.

Running Phases

Running has been classically described by the bouncing/pogo-stick paradigm (Margaria 1976) in which Elastic Energy has a crucial role. In a pogo stick or in a spring, part of the Total Energy of the system during the flying phase is transformed into Elastic Energy during the first half of the contact phase via tendon stretch. In the second half of the phase a consistent part of the stored energy is given back to the system via tendon recoil. In contrast to an ideal pogo-stick, some mechanical energy is necessary to keep the system moving. Muscle in fact sustain an elevated energy consumption which is inversely proportional to the contact time (Kram and Taylor, 1990).

This engages the natural body’s spring mechanism by utilizing eccentric contractions of the muscle at the ankle, knee and hip during landing.

To be efficient we should land with the foot aligned with the centre of mass and not in front of it to avoid breaking. In this way we can help to avoid any breaking and that of accumulating elastic energy thanks to the spring mechanism of the tendons.

However, in sports we have to be efficient in saving energy (as for long distance running or for transition running in team sports such as football) and in some situations we also need the capability of executing different tasks requiring high power: sprinting, changing direction, moving laterally etc.

Thus, in a sport like football we need to face two different tasks: being economical and saving energy when running at a low speed (the so called transition running in football) and being able to produce the highest amount of force in a very short time – power – when sprinting.

The basic parameters to analyze the fundamental locomotion pattern in sports are: cadence, step and stride length, vertical oscillation and ground contact time. They can be analyzed and visualized when doing specific sessions in a lab, but we can use a simple parameter that properly summarize that fundamental parameter and helps to ‘quantify’ energy production when running.

It is represented by WATTS.
Watt is the standard unit of power, it is equivalent to one joule per second and it is directly influenced by:

• speed - the higher the speed the higher the watt;
• cadence - at a given speed the higher the cadence and the lower the watts;
• ground contact time - at a given speed watt decreases with decreased contact time.

How to improve your running with the SKILLRUN treadmill

SKILLRUN is an innovative treadmill in which power can be, monitored, trained and tested. Specifically, two basic and opposite capacities can be trained to:

The capacity of being economical can be obtained when, at a given speed, a less amount of power is produced. On SKILLRUN there are specific functionalities aimed to achieve that goal constituted by the set of biofeedback parameters (where watts can be visualized on time) and more specifically by the cadence training workout. This workout is designed to train the capacity of running at different cadences while maintaining a constant speed, thus improving the neuromuscular control. It is well known in fact that when tired, long distance runners tend to decrease their cadence and increase stride length, becoming less efficient and increasing the risk of injuries due to the worsening of some fundamental kinematic parameters:  higher centre of mass displacement, higher braking impulse, higher ground contact time, wrong landing strategy (rearfoot rather than forefoot stricker).

The capacity of producing the highest amount of power when sprinting or pushing against an external resistance relies on two basic pre-requisites: strength and speed, power being the product of the two. For the first time on a treadmill the SKILLRUN offers specific programs aimed to increase strength, thanks to the sled training and to improve speed thanks to the parachute training. On both the sled and parachute training, all of the specific parameters of the training can be defined and monitored: weight of the sled and dimension of the parachute, distance to be covered, number of repetitions, achieved power, time to peak power etc.

In conclusion, SKILLRUN constitutes an innovative training platform for all athletes that requires the practice of either endurance or power.

How cadence and contact time influence running economy

Cadence. Experienced runners would select a stride frequency closer to the optimum (minimal energy costs) than would novice runners (Cornelis et al. 2014). When non-fatigued, experienced runners naturally optimize stride frequency in a manner that minimizes oxygen uptake (Huntyer and Smith).

Contact time. Several authors have shown an inverse relationship between running economy and ground contact time (Williams and Cavanagh, 1987; Chapman et al., 2012;Di Michelle and Merni, 2014). Muscles in fact sustain an elevated energy consumption which is inversely proportional to the contact time (Kramer and Taylor, 1990).