While hiking in mountainous areas, individuals experience an array of terrains, and one which is particularly damaging is downhill walking. Researchers gathered data and found that performing small amounts of downhill walking prior to longer, more extensive hikes, reduces muscle damage and risk of injury.
Walking mountainous areas is a popular activity with physical and mental health benefits. However, this level of activity also comes with risks, particularly for seniors and novices. Hiking or trekking through mountainous areas requires traversing different terrains, which can lead to muscle damage and injury or death from falling.
Muscle damage is mostly incurred during the downhill walking portion of treks. During downhill walking, the lower limb muscles are active in extending the knee to slow speed and control motion. This can lead to small tears in the muscles which decrease muscle strength and coordination, increasing the risk of falls on the trek and in the near future. Muscle damage can generally be reduced by performing the same activity repeatedly as the body adapts to stressors. Also, muscle damage does not need to occur for adaption, merely the same exercise or movement needs to be repeated to decrease muscle damage. As such, scientists tested the theory that performing a shorter, less stressful downhill walk prior to a mountainous trek would reduce muscle damage and in turn, reduce the risk of falling.
In this study published in PLOS, Maeo et al. tested the hypothesis that a shorter downhill walk would reduce the muscle damage incurred by a later, longer downhill walk. Untrained men with an average age of 23.5 were subjected to one of two experimental pre-conditionings or were a control. One group performed a 5 minute downhill walk, while the other group performed a 5-minute level walk, both at 5 km/h with a load of 10% body mass (to simulate hiking equipment). The control group did not have any pre-conditioning and all three groups performed a 40-minute downhill walk at 5 km/h with a load of 10% body mass a week after pre-conditioning treatment. The individuals were tested after the 40-minute walk for knee extensor strength, plasma creatine kinase activity (a marker of muscle inflammation), and self-reported muscle soreness.
The results showed that despite no muscle damage being incurred by either 5-minute walking treatment, individuals who walked downhill for a short distance prior to their longer trek incurred significantly less muscle damage than both the control and the level walking treatment group. Knee extensor strength, muscle inflammation, and muscle soreness were all markedly lower for the group that pre-conditioned with a 5 minute downhill walk, while the level walking treatment group did not provide significantly different results from the control group.
The findings suggest a way for individuals to prepare themselves for long hikes to reduce muscle damage and risk of falling. It should be noted that this study was not able to determine the underlying mechanism of the reduced muscle damage. Further studies should explore this theme, as well as if this effect is scalable to longer treks, for example, a 40 minute downhill walk prior to a 5 hour downhill walk. It is recommended that people looking to go on a mountain trek, particularly seniors and novices, prepare by engaging in a short downhill walk in the days prior to their activity to reduce the risk of injury.
Written By: Wesley Tin, BMSc