Neural adaptations can be responsible for different strength gains, despite similar muscle mass from person to person. Building muscle can be different from case to case. Now, there is scientific data to support this theory. Brain cells can be responsible for this as there could be more electrical signals sent to the muscle with higher repetitions and lower weight compared to lower repetitions with higher weight.
Neural adaptations study and findings
A 2017 study[i] made by the University of Nebraska-Lincoln build on empirical data and showed how neural adaptations can be responsible for different strength gains. These gains can be similar, regardless of the weights, but with different repetitions.
Researchers took 26 men and chose leg extensions as the base exercise for the study. Two groups were formed. The first group used a load of 80% of the maximum weight they could lift. The second group used 30% of their maximum handled weight. While the first group did fewer repetitions, the second group performed the exercises with higher repetitions, due to the lower weights. After three workouts each week for a total of six weeks, researchers concluded that the heavy-load group improved voluntary activation by 0.15% while the light-load group improved voluntary activation by 2.35 percent. So what caused these results?
In simple terms, muscles are activated by the brain through electrical signals. These signals are triggered by the neuron motor cortex. This then leads to muscle excitation which is responsible for contractions. These signals could be activated to a larger degree for those performing a higher number of repetitions. It is why the study found better strength gains for this group. Researchers concluded that training with higher frequency repetitions leads to better strength adaptations. This is constant for amateurs, average lifters or athletes.
Of course, the research has vast interpretations and it could be a great base for further investigation. One of the areas which are critical to assess comes with fatigue. Researchers believe that simply lifting lower weights every day is more practical on the long-term. This is due to possible delayed muscle fatigue.
The study can also be the ground for new research when it comes to joint impact and the training of the elderly. But even if the results are similar with different loads, the researchers do not exclude the possibility of training with heavy loads based on a low number of repetitions. For those who have busy lifestyles, this method of training remains a good option. People with busy lifestyles can also consume an amino acid supplement, as 9 out of 20 amino acids cannot be produced by the human body and they need to come from foods.
Neural adaptations are responsible for strength development in both low and high-intensity training and it goes to show that muscles are largely impacted by the brain and its electric signals. The research can be applied in different ways. For some people, it means that higher frequency with low weights can mean building muscle with reduced fatigue. But the traditional heavy loads with fewer repetitions should not be excluded. It is yet to be seen how these two types of training methods can be combined for more complex workouts.
[i] N.M.D. Jenkins, A. Miramonti, E.C. Hill et al. (2017), Greater Neural Adaptations following High- vs. Low-Load Resistance Training, Frontiers of Physiology Journal. Available at: