The importance of ascents / descents in runner training 📈📉
ascents 
This is the "star" training session for runners.
It must be taken into account that when facing an ascent, there is an extra expenditure of energy compared to a flat floor.
The main objective of betting on this training is to give the runner the necessary strength to face with vigor and dexterity all types of climbs, trying to use as little energy as possible.
We will also improve our posture a lot, which is still very important because one of the main reasons for technical inefficiency in runners is the lack of muscle strength.
We suggest alternating inclination and duration so that the body does not get used to a certain routine. As an alternative to working uphill we have stairs, steps, horizontal jumps, etc.
descents 
Often runners consider the descents as a well-deserved rest after the ascent. In our opinion, this is a mistake, since the descent requires concentration (especially on trails) so as not to make mistakes and end up overcoming the fatigue of the climb. On the other hand, it must be borne in mind that the descent also represents a greater expenditure of energy for the corridor compared to a flat floor. Therefore, if there are expenses, it is necessary to train to reduce them and avoid the risk of injury due to the dreaded muscle sprains or ruptures. As in the previous topic, we recommend variability in the duration and slope of the descents.
You can train going down stairs, steps or horizontal multi-skipping on surfaces with a slight slope.