Loss of flexibility is a standard consequence of prolonged running practice. But probably few amateur athletes see it as a benefit. Most runners, on the contrary, strive in every way possible to prevent lower limb stiffness and to increase flexibility through stretching exercises.
But for some reason, unlike all the other changes that happen to the athlete’s body during training (increased bone density and mitochondria in the muscles, optimization of glycogen consumption, reduction of fat reserves, etc.), we tend to view the loss of flexibility as a harmful side effect?
In fact, this factor is not negative. Like everything else, the loss of flexibility due to running is an adaptive process that plays a positive role and helps to achieve better results.
A study at the California Institute found an inverse relationship between flexibility and running economy. In other words, the harder it was for the runner to bend over and touch his toes, the more economical his running was.
This adaptation of muscles and ligaments to running creates a more powerful and responsive biomechanical complex, which can be compared schematically to a spring. Less flexibility actually leads to the fact that elastic tissues can store and release more energy. This makes a serious contribution to the economy and rationality of long-distance running, on a par with proper technique.
But all of us, including professional athletes, do stretching exercises from time to time in one way or another. Why?
The fact is that flexibility is not a bad characteristic in an absolute sense. We need to maintain a normal range of motion in the joints of the musculoskeletal system. Fast runners usually have a slightly larger range of motion in the hips than slow ones.
Running by itself cannot reduce the range of motion in the joints, but a sedentary lifestyle and wearing heeled shoes lead to incorrect posture and overstretch the muscles. For example, sitting creates a pseudofunctional contraction of the hip flexors, and heels also affect the calf muscles and Achilles tendon.
In addition, our overall flexibility, and thus the range of motion in our joints, decreases as we age. This can compromise our running performance at some point. Therefore, using stretching exercises to prevent aging defects and especially with a sedentary lifestyle is a good idea.
Nevertheless, if you, being a marathon runner, cannot reach your toes with your hands in a forward bend, there is absolutely nothing wrong or scary about that. Under normal circumstances, this fact is the body’s response to prolonged training to increase the elasticity of the ligamentous tissues of the musculoskeletal system.
At the same time, it is worth remembering that physiologists associate some injuries with muscle tightness. Especially the posterior muscle groups – gluteal and calf muscles. This can occur in long-distance runners.