Acclimatisation to High Altitude – POWERbreathe IMT is Beneficial

There is a new Review Article in Frontiers in Physiology (January 2019) that looks into using respiratory/inspiratory muscle training for acclimatisation to altitude.

Respiratory muscle training

Respiratory muscle training, or RMT, is a programme of exercises that aim to improve the function of the respiratory muscles. Otherwise known as the ‘breathing pump’ muscles, the expiratory muscles and the inspiratory muscles make up the respiratory muscles. It’s the inspiratory muscles that we use when we breathe in. The main inspiratory muscle is the diaphragm, but to a lesser extent, the intercostal muscles also help with inhalation. To help improve the strength and stamina of these inspiratory muscles, respiratory muscle training will include Inspiratory Muscle Training (IMT).

Inspiratory Muscle Training

Inspiratory muscle training, such as with POWERbreathe, uses resistance to provide the training effect. When breathing in against the resistance, the breathing muscles have to work harder. As a result, they get stronger. Consequently, breathing stamina improves resulting in a reduction in breathing fatigue. There is numerous research validating this form of breathing training and, as a result, it is the most commonly used.

The review

For the review, researchers perform a comprehensive search, analysing seven appropriate studies. Three of these studies refer to using respiratory muscle endurance training (RME with isocapnic hyperpnea). However, the remaining four studies use respiratory muscle strength training (RMS with POWERbreathe IMT).

Acclimatisation to altitude

Studies suggest that respiratory muscle training with IMT is a useful preparatory method for enhancing respiratory muscle efficiency 4-6 weeks before being exposed to hypoxia/altitude.

It is evident that breathing during exercise in hypoxia is associated with increased energy costs (20–30%) when compared to normoxia. Therefore, it is more likely to cause respiratory muscle fatigue. However, inspiratory muscle training will help to combat this. This is because IMT trains the inspiratory muscles to become stronger, increasing stamina. Consequently, breathing muscle fatigue reduces.

It, therefore, seems apparent that breathing muscle training has the potential to minimise at least some of the limiting respiratory factors that occur during training and competition in hypoxia/at altitude.

Benefits of acclimatisation to altitude using IMT

The Review suggests that both elite athletes and non-elite individuals may benefit from RMT, including:

  1. A delay in the onset of premature fatigue.
  2. A delay in respiratory muscle metaboreflex onset/activation.
  3. An improvement in clearance and tolerance to anaerobic metabolite products.
  4. A decrease in the perception of dyspnea (‘air hunger’).
  5. An increase in oxygen saturation values.
  6. A more favourable blood redistribution to the locomotor muscles.

Finally, evidence from this review finds that respiratory muscle training is an effective stimulus for improving the strength and endurance of the respiratory muscles. In fact, it’s these adaptive responses that contribute to the improvement of ventilatory function and efficiency. In translation, this means that respiratory muscle training is very likely to improve exercise performance in normoxia and particularly in hypoxia/altitude.

Influence of IMT on Cycling Performance at altitude

This study, Influence of IMT on Ventilatory Efficiency & Cycling Performance in Normoxia and Hypoxia, is published in Frontiers in Physiology. The aim of the study is to analyse the influence of inspiratory muscle training (IMT) on ventilatory efficiency in normoxia and hypoxia. It also investigates the relationship between ventilatory efficiency and cycling performance.

The point of the study

The premise of the study is that IMT improves ventilatory efficiency in normoxia and hypoxia. It also reduces the metabolic demands of the respiratory muscles in both conditions. The study also hypothesizes that improvements in submaximal cycling performance can be linked to improvements in ventilatory efficiency in normoxia and hypoxia.

Study method

The study assigns participants, at random, to either a control group or an inspiratory muscle training (IMT) group. The IMT group were to complete 30 inhalations twice a day using the POWERbreathe K3. They were to do this 5 days a week for 6 weeks. Researchers set the POWERbreathe K3 to 50% of each participant’s Pimax (maximal inspiratory mouth pressure). By contrast, the control group did not perform any IMT.

To determine Pimax participants had to inspire through the K3 as quickly as possible. And in order to achieve a stable measurement they were perform this a few times.

Conclusions for training at altitude

The study suggests a possible positive effect of IMT on cycling time trial performance in both normoxic and hypoxic conditions. It also shows that hypoxia has a negative effect on ventilatory efficiency. It furthermore shows that IMT may reduce this effect.

Additionally the authors report that these findings may have relevance for athletes planning to train at a high altitude, or compete at high altitude.

Finally, the study suggests that Inspiratory Muscle Training before a competition at altitude might be a successful method to improve performance.