Training Respiratory Muscles to Increase Cardiovascular Endurance
Discussion in a Grouse Grind® made me curious as to whether or not Alternating Nostril Breathing (ANB) or Respiratory Muscle Training (RMT) could lead to faster times up the mountain. The ultimate goal in endurance events is to be able to move faster at lower heart rates and lower ventilation rates while also maximizing the use of oxygen. Only RMT will be discussed for today with another article to follow about ANB.
The respiratory muscles which include the intercostals and diaphragm are just like any other muscles. They are capable of fatiguing, but also responsive to resistance training.
Breathing accounts for “10-15% of an athlete’s oxygen consumption during maximum intensity exercise” as reported in ScienceDaily. Turner’s study found that after six weeks of inspiratory muscle training (IMT), cyclists needed "1 percent less oxygen during the low intensity exercise and required 3 to 4 percent less during the high intensity exercise.” (1) It seems that improving their endurance would provide more energy the muscles need in locomotion.
It has been known for several years that aerobic activity of greater than 85% VO2 max, lasting greater than 8-10 minutes causes diaphragmatic fatigue. (2) The consequences of this fatigue is a restriction of blood flow to working muscles such as the legs during the Grind, which induces muscle fatigue. (3) Turner’s next study is to see if IMT leads to a greater amount of oxygen being available for the legs.
RMT training has been used with great success for patients with asthma, cystic fibrosis and chronic obstructive pulmonary disease. During the last 15-20 years there has been more emphasis on high performance athletes using this type of training with claims of 4.7% improvements in performance for some Olympic teams. There seems to be more awareness of IMT with the general public. There are different inspiratory training devices like the PowerLung and SpiroTiger to make the respiratory muscles stronger and have more endurance.
A study in 2000 by Inbar, et al, showed that inspiratory training can improve respiratory muscle endurance in well trained athletes, however they did not show any improvements in VO2 max. (4) VO2 max has been thought to be a determinate of endurance performance, however there has been a recent shift to time at VO2 max and time at lactate balance point. It would be interesting to see if IMT training leads to increased time to fatigue, as well as what changes there are in heart rates and ventilation rates for the same exercise intensity post-IMT.
There seems to be a lot of research on inspiratory training but little about expiratory training. In 1995, a study by Suzuki, et al, had participants complete 15 minutes of EMT training twice per day for 4 weeks. Minute ventilation decreased, and expiration time increased, as did the breathing frequency during exercise after EMT. (5)
Respiratory muscle training has been shown to decrease time to exercise exhaustion, increase maximum voluntary ventilation and reduce ventilator fatigue. (6) Alveolar ventilation, the amount of air available at the alveola, increased as did lung function but there were no changes VO2 max in an 8-week training program of 5 sessions a week with progressive loading using the SpiroTiger. (6)
Respiratory muscle training will reduce your oxygen demands and limit your fatigue.
Do you need a high-tech device to train your respiratory muscles? A 4-5% increase in performance is critical if it means the difference between placing or not in events where prize money and sponsorships are on the line. However, for the amateur athlete who is training for a personal record, I would start by trying some daily breathing exercises such as learning to breathe properly using the diaphragm while also incorporating other types of training such as time to fatigue at VO2 max and speed at Lactate Balance Point.
Give yourself 6-8 weeks of 15-30 minutes of breath training 5 days a week to notice the difference. The beauty of this type of training is that it can be done anywhere. It also has many more benefits, such as reducing your blood pressure and lowering your stress. Another tip is to try to lengthen your breaths. For example, count the number of steps you take for each inhale and exhale, then try to take 1 or 2 more.
Try these diaphragm breathing exercises.
Respiratory Muscle Training References
- 1University I. Inspiratory Muscle Training and Endurance Sport Performance. ScienceDailyJune 2010. http://www.sciencedaily.com/releases/2010/06/100603091628.htm
- 2Johnson BD, Aaron EA, Babcock MA, Dempsey JA. Respiratory muscle fatigue during exercise: implications for performance. Med Sci Sports Exerc 1996;28(9):1129-37.3.
- 3Romer LM, Polkey MI. Exercise-induced respiratory muscle fatigue: implications for performance. J Appl Physiol 2008;104(3):879-88.
- 4Inbar O, Weiner P, Azgad Y, Rotstein A, Weinstein Y. Specific inspiratory muscle training in well-trained endurance athletes. Med Sci Sports Exerc 2000;32(7):1233-7.
- 5Suzuki S, Sato M, Okubo T. Expiratory muscle training and sensation of respiratory effort during exercise in normal subjects. Thorax 1995;50(4):366-70.6.
- 6Esposito F, Limonta E, Alberti G, Veicsteinas A, Ferretti G. Effect of respiratory muscle training on maximum aerobic power in normoxia and hypoxia. In: Respir Physiol Neurobiol. 2010/02/17 ed; 2010. p. 268-72.List Element