A simple question, which I will try to answer in this article.
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To answer this question, we need to take a step back and clarify some fundamental concepts in the world of two wheels.
The bike is an extraordinary tool, which requires human muscle power to move. More precisely, it is necessary to push on the pedals. Both in the initial phase and in the traction phase, the movement involves a very marked concentric component: the muscle shortens, generating the force necessary to overcome an opposing force.
This concept has been developed far and wide and there is a unanimous opinion that exercises such as the squat or the press in all its variations are the best exercises for strength training in cyclists.
There are still two different schools of thought, between those who believe that they are an important quality to train even during the year and those who instead consider it secondary.
But if we shift our attention from the pedaling action to the qualities needed to ride a downhill MTB, we realize that the discussion changes radically, and with it the qualities to train.
A little bit of technique
To better understand the muscular dynamics involved in downhill skiing, it is necessary to describe what happens during a technical descent.
To do this, I took inspiration from the technical analysis of skiing. So let's start from the beginning, dividing the descent into two main sections: broken straights e curve.
- Broken straights
In straight, more or less uneven sections, We have to deal with the force of gravity, which on one side pushes us, on the other, especially in the presence of roughness or compressions, crushes us and must be counteracted.. At every hole, compression or rock garden, the legs and arms must absorb the shocks. In this phase, the muscles work in a eccentric, a movement similar to that made when jumping off a low wall to cushion the landing. - Corners
In curves, however, the force to overcome will be the centrifugal one, which will try to push us off the trajectory or crush us against the bike. Even in this situation, the centrifugal force comes into play. eccentric, necessary to maintain control.
So what? Eccentric strength training is key!
In summary, to go fast downhill it is essential to train eccentric strength, since it is what allows us to absorb the forces that act on us in each phase of the descent.
But didn't people once talk about pumping up their bikes?
Here another aspect comes into play.
If the bike is set up correctly, our role is to support its functioning, making the most of it. Let's take for example the gesture of taking a curve:
- Under braking: inertia will push us forward as the bike slows down. To maintain a central position on the bike, the muscles will have to resist the forces that tend to unbalance us. Here we are not pushing, but we are resisting.
- Corner entry: centrifugal force pushes us towards the outside of the trajectory. If the curve is banked, the force of gravity is also added, pushing us towards the ground. Even in this phase, it is the eccentric force that comes into play.
- Exiting the curve: if we have worked well (and the bike is set up correctly), the compression of the suspension will release energy, pushing the bike towards acceleration. Here our task will not be to push, but lighten the muscles, allowing the chassis and fork to do their job.
More than a concentric work, we are therefore talking about tension management and release, to allow the bike to “run away” and accelerate out of corners
In the gym: focus on eccentric exercises
For now, what should interest us is that the focus of gym training should be on exercises eccentric, we will talk about it in depth next week
