Hi,
While watching the starting game of the Euro 2016, I try to provide some insights of Zoi based on my experiences until now, and also provide an overview what kind of metrics you can measure with the device.
Basically there are the following data available (see the Runteq website for more information):
The core metrics
- Ground Contact Time
- Step rate (Cadence)
- Body Strike Level
- Vertical Displacement (”Bounch”)
- Fluctuation of forward speed (”Braking”)
- Footstrike type (forefoot, midfoot, heel)
- Footstrike impact
- Rotations of foot
The derived metrics
- Zoi® running score
- Biomechanical economy
- Injury Risk
- Gait Cycle
- Step and stride length
Note that some of these are available during a workout whereas the others cannot be studied before the end of the workout. The image below illustrates the technique view in the Zoi app during the run.
Technique screen of Zoi
Step Rate (Cadence)
The metric step rate provides data about whether you are running at an optimal step rate – it should be about 180 steps per minute. According to several researchers professional runners typically have a step rate of 180 – 200, whereas the recreational runners posses one of 150 – 170. The step rate stays pretty much constant and only the step length changes depending on the speed.
As you can see, I still have some work to do in order to get my step rate above 180 steps/minute.
Ground contact
The ground contact time denotes the amount of time your foot is in contact with the ground on each stride. Obviously the ground contact time decreases, when the pace increases, and the short ground contact time seems to be an important factor towards more economical running with smaller risk for injuries. Many studies point out that probably the easiest way of reducing the ground contact time is to switch from a heel strike to a mid-foot strike.
Now I know that I should aim at decreasing the ground contact time and it should be fully possible, if carrying Zoi with me during the following months.
Bouncing (vertical oscillation)
If the runner tends to do bouncing, he loses energy to vertical (up – down) movement. It also slows the runner down, as too much time is spent in the air. The muscles are loaded more and the runner has to struggle more to pick up the speed after a bounce. By reducing the grade of bouncing the running can be more economical. For a beginning runner it may be comforting to hear that usually the problems with the bouncing are reduced, when the runner gets more training. Moreover, by keeping the steps short and close to the ground the problem should be addressed. Also, emphasising the running to the middle part of the foot instead of the heel or toe part makes the runner bounce less.
My value for bouncing during the first workouts with Zoi has been about 6 – 8 cm which should be pretty OK, but obviously even in this respect there’s room for improvement. Especially I’m interested in the values during the long run when I get more and more exhausted and the running technique probably gets a hit due to that.
Asymmetry
Many injuries caused by running can probably at least partly be detected and prevented by the running metric of asymmetry. Each human being has a stronger hand, leg, side in the body etc. and this is also reflected in the running technique. Rotations and tilts may be a root of many problems, and if you have pain anywhere, it should be addressed before tackling the problem with a change in the training.
During my first workouts with Zoi I haven’t seen any especially worrying figures for the asymmetry but I also try to keep my eye on it. A little bit of strength training would probably also be beneficial for the running technique. Let’s see, if I’m able to start with it, as until now I have been really lazy, when it comes to the muscle training.
Braking
Finally there’s the metric of braking. This indicates how much energy is wasted if the runner’s movement is not optimal. To prevent and diminish the impact of braking the runner should aim at speeding up the foot backward before the foot hits the ground.
The braking seems definitely to be the area I have most problems at the moment, and I really should concentrate on changing my technique. I really hope and believe it is possible with Zoi!
Sometime in the near future I will have a look at the results Zoi provides after a workout. At the moment I’m really excited about the possibilities offered.