The regular use of strength training has been slow to catch on with endurance athletes. While there is evidence that strength training decreases both acute and chronic injury in these athletes, and improves running and cycling efficiency by 3-8% many endurance athletes simply do not enjoy lifting weights. This may be due in part to what is being trained. Traditional programs focus on the major muscles of the legs, hips, back, and shoulders of endurance athletes. A new trend has emerged in recent years that includes the training of the muscles used in breathing.
Breathing is something we take for granted. We don’t think about the work that goes on every time we breathe, either at rest or during normal daily activity. During very intense exercise, like that experienced during interval training or racing, up to 15% of the energy produced is consumed by respiratory muscles. This is energy not used to make the athlete go faster and can put a pretty big dent in your body’s carbohydrate stores, requiring more fueling during the event.
There are several respiratory training devices on the market designed to improve the strength and efficiency of the inspiratory musculature, those muscles that allow us to inhale. This is done by increasing airflow resistance through a special valve.
A study from Great Britain examined the effects of 11 weeks of inspiratory muscle training on rowing performance as measured by a 6-minute all-out test and a 5000 m test both on the Concept II rowing ergometer. Fourteen female competitive rowers (All-British National Team candidates) participated in the study. They were broken into two groups. The first, trained twice a day using 30 breaths per session at a resistance equal to 50% of the maximum inspiratory pressure they could generate (inspiratory pressure is the maximum pressure that can be generated when breathing in). The second group, a placebo group, trained once a day, 60 breaths with 15% of maximum inspiratory pressure, a training protocol that does not significantly increase inspiratory muscle strength. The athletes were tested at the start of the study, at four weeks, and again at the end of the study.
The training group improved their 6-minute test performance by 3.4% after four weeks of breathing training while the placebo group only increased by 1.1%. By the end of the 11 weeks the training group had improved by 3.5% and the placebo group had improved by 1.6%. The researchers suggest that the difference of 1.9% improvement between the two groups is the result of the inspiratory muscle training.
In addition, the training group improved their 5000 m test time by an average of 36 seconds, while the placebo group improved by only 11 seconds. These results were brought about by a 41% improvement in respiratory muscle function for the training group and 5% for the placebo group, as measured by an increase in maximal inspiratory pressure.
While a 1.9% net improvement doesn’t seem like a lot, many races are won or lost by much less than 1.9%. This is equal to almost seven seconds over a 2000 m course. One of the interesting things to come out of this study was that almost all of the performance improvements came in the first four weeks of the eight week training program. This may be due to the fact that the resistance was self-adjusted during the study and not subject to a periodized plan.
While respiratory muscle training does not solve all an endurance athlete’s performance problems, the results of this study clearly suggest that a high level athlete may benefit from respiratory muscle training. Whether these results can be applied to athletes with lower fitness levels remains to be seen. Additionally, there is still a lot of work to do to find the most effective training program for these muscles.
The main mistake that people make when using inspiratory muscle training devices is that they try to train while using the device. This is nearly impossible if the device is set up properly. These machines are meant to increase the resistance to airflow coming into the lungs. It is like lifting weights for your diaphragm and other breathing muscles; you wouldn’t try to do squats while riding your bike would you? Set up a training session using sets and reps just like weight training. Start with 3-4 sets of 8-10 reps, gradually increase the resistance on the inspiratory trainer over a period of 4-8 weeks.
Inspiratory muscle training is not going to suddenly cause huge changes in your race performances but it is one of the small things that you can do without a lot of cost or effort. If you do enough small things they can all add up to big performance improvements.
(As a side note, personal communication with rowing coaches from Britain and Australia revealed that at least two medal winning boats from the Sydney Olympics included inspiratory muscle training as part of their preparation for the Games.)
Voliantis, S., McConnell, A., Koutedakis, Y., McNaughton, L., Backx, K., and Jones, D. (2001). Inspiratory muscle training improves rowing performance. Medicine and Science in Sport and Exercise. 33(5) pp 803-809.