A recent research paper in Experimental Physiology looks into the effect of an increase in inspiratory muscle work on blood flow to inactive and active limbs. It addresses the process of metaboreflex.
What is metaboreflex?
Metaboreflex is where the body restricts blood flow to the limbs when the breathing muscles fatigue. The body will do this to ensure the role of breathing continues. This is because breathing is crucial to survival. Therefore, when the body experiences a conflict between breathing and moving, breathing wins out.
How does metaboreflex work?
As soon as the body senses a conflict between breathing and extreme activity, it will redirect blood flow to the breathing muscles, for survival. In so doing, blood flow to the exercising limbs shuts down, allowing the diaphragm a chance to recover. What this tells us is that the stronger the diaphragm is, the faster it will recover. Consequently, stronger breathing muscles will, in turn, result in a better blood supply to your working limbs. This will result in a better sports performance.
These YouTube videos from breathing expert James Fletcher, clearly demonstrate the metaboreflex.
When exercising, the amount of energy consumed by the working muscles can be high and prolonged. Blood flow to these working muscles needs to be matched. The results of this study suggest that the control of blood redistribution to the working muscles is facilitated, in part, by respiratory muscle-induced metaboreflex.
Delaying the onset of metaboreflex
Improving the strength of your breathing muscles will help to delay the onset of the metaboreflex for the diaphragm. A scientifically proven way of doing this is with Inspiratory Muscle Training (IMT). In fact, there are other studies showing IMT to be beneficial too.
This award-winning research, awarded by the European College of Sport Science (ECSS), also suggests the potential role of IMT to reduce inspiratory muscle metaboreflex.
Another study suggests respiratory muscle training could enhance sports performance by delaying this process.
Finally, there is a study by Germain Fernandez Monterrubio, Bachelor of Science in Physical Activity and Sport, in which he finds how respiratory muscle fatigue can affect exercise tolerance on a pulmonary level, as well as, a muscular level.