A new study on weight lifting has revealed that the practice can strengthen the connections between nerves and muscles, and that this strengthening can still happen later in life.
In fact, we begin to lose muscle mass before the age of 40, which is partly caused by the contraction of muscle fibers that occurs when motor neurons, the cells in the brain and spinal cord that make our bodies move, are destroyed.
This decline cannot be stopped, but scientists have concluded that it can be significantly slowed down. Strength training strengthens connections between nerves and muscles, protecting motor neurons in the spinal cord, according to the study.
This is partly due to the difficulty in collecting enough tissue at the junctions of muscle and nerve cells to allow meaningful measurements. To overcome this, the researchers instead looked for biomarkers associated with the stability of connections between neurons and muscles in participants’ biopsy samples.
The study involved 38 healthy older men, with a mean age of 72, who were asked to complete a 16-week course of fairly intense weight-lifting training, including leg presses, leg extensions, leg curls, and two forearm exercises. Another group of 20 healthy older men, again with a mean age of 72, did not train with weights and was used as a control comparison.
Weight training was done three times a week, and after two months, differences in muscle size and fitness could be seen. The researchers collected muscle biopsies and found noticeable changes in biomarkers.
From back pain to knee pain, this indicates that strength training can slow down some of these disruptions between muscles and the nervous system without actually reversing them. The researchers suggest that if you start exercising earlier, you can create “reserves” to which the body can still return.
Although this study was done on men, this also applies to women: for example, older women, who are more prone to osteoporosis, benefit from strength training just as much as men.
In the next step, the researchers will try to figure out how strength training helps nerves and muscles stay together.