We all know that oxygen demand and supply are important for exercise. Oxygen is what allows our muscles to keep contracting, and subsequently keep exercising at our intended intensity. When the supply of oxygen to working muscles is slowing down, this is what typically stops us from continuing. Two factors that may help improve the oxygen supply to our muscles include the amount of capillaries within the muscle and the dilatory function of these.
Even though there is a reduced amount of oxygen when in hypoxic conditions, exercising in hypoxia actually improves the amount of capillaries within muscle and the ability of these to dilate and constrict compared to training in normal conditions. This was concluded following an extensive review of current research by researchers based in Switzerland. They found that across 21 studies, skeletal muscle capillarisation and dilator function increased more so following exercising in hypoxia compared to normoxia for 3 to 10 weeks of primarily cycling exercise. One of the reasons for this positive response that occurred was due to the compensatory increases in blood flow to the working muscles when in hypoxia which doesn’t occur in normoxia. As such, exercising in hypoxia creates a short-term reduction in blood flow which is then reimbursed following cessation of exercise. Without this, increases in capillarisation and dilator function are unlikely to be maximised.
So what can we take from this? Exercise if often terminated due to a lack of oxygen supply. To improve oxygen supply, one should consider increasing the amount of capillaries and the dilator function of these. Even though exercising in hypoxia presents a lack of oxygen availability, this increases the amount of capillaries and the dilator function of these more so compared to normoxia. Perhaps this isn’t at the forefront of your mind during training or preparing for a race, but positive effects can be achieved following just three weeks of training and this can’t be ignored!
If you’d like to take a look at your muscle oxygenation prior to carrying out a training block, then then take a look at our Muscle Oxygen Consultations.
Montero & Lundby, (2016). Sports Med, 46, 1725-1736.