Inspiratory muscle training, also called respiratory muscle or breathing training, is a special form of resistance training for increasing the strength and fatigue resistance of your inspiratory muscles.
Despite having a sizeable amount of research supporting its effectiveness for runners, cyclists, and swimmers, it’s not widely used by endurance athletes.
In this article, we’re going to look at:
- What is inspiratory muscle training?
- Current research showing its effectiveness
- How to use inspiratory muscle training to improve exercise performance
What is Inspiratory Muscle Training?
Inspiratory muscle training is a type of resistance (strength) training for improving the strength, efficiency and fatigue resistance of your respiratory muscles. The training approach is very similar to a standard resistance workout — the difference here is that we breathe against a resistance.
What are the benefits of respiratory muscle training?
When we train our respiratory muscles consistently over several weeks, our lungs adapt, become stronger and more fatigue resistant.
This makes exercise feel easier and allows you to exercise for longer or at greater intensities. It’s also beneficial for anyone with breathing difficulties, so may benefit athletes who suffer with asthma.
How it improves exercise performance
With endurance exercise, one major limiting factor is the metaboreflex.
What is metaboreflex?…
It sounds complex, but this just describes a phenomenon where your body restricts blood flow to your limbs when respiratory muscles become fatigued.
It’s a natural protective mechanism that serves to ensure that your lungs can continue to meet the oxygen demands of your body.
All you need to know is:
- When this happens exercise is compromised
- By strengthening your breathing muscles, you can protect against this, preserve blood supply to your muscles, and improve exercise performance.
Besides the strength training benefits, it’s also proven to be an excellent warm-up exercise that improves exercise performance.
Research Proven Benefits of Inspiratory Muscle Training
There is a substantial amount of research supporting the use of breathing training.
One point to note here: this is not the same as altitude training masks.
While inspiratory muscle training is research backed, we cannot say the same for altitude training masks.
Let’s start by looking at inspirator muscle training for runners.
Improved Running performance
With running, research has revealed an obvious benefit from inspiratory muscle training across a range of distances (800m-5k).
Here, it benefits running when used as part of a specific training block. And also when used as part of a pre-workout warm up. It’s also proven to improve the effectiveness of interval training and enhance recovery between intervals.
800m running performance
While you might not expect to see a benefit with middle distance events such as 800m running; previous research has highlighted that 400 and 800m running can lead to significant levels of inspiratory muscle fatigue (1).
This led researchers to suggest that coaches should consider IMT training to reduce the effects of respiratory fatigue during maximal running.
And they were right…
In a recent study, researchers discovered that four weeks of respiratory training significantly improved inspiratory muscle strength and 800m running performance in a group of college runners (2).
The key points here were the short duration of the research and the relatively easy training integration — just 30 resisted breaths, completed twice daily at 50, 60, 70 and 80% of maximum inspiratory pressure.
3.2k (2mile) running performance
Using an inspiratory muscle warm up before a running time-trial has also proved beneficial (3). Here, the runners completed 30 breaths at 50% peak inspiratory muscle power before the time trial. This improved their 3.2k time trial by nearly 3%.
5km running performance
In another study (4), researchers looked at the effects of 4 weeks of inspiratory muscle training (30 breaths daily) on 5000m running performance.
During the study, they separated the runners into two groups — both groups completed interval running workouts, while one also included inspiratory training.
One point to note here was the respiratory training appeared to benefit interval training, which led to improved 5k running performance. Further to this, research published in the Journal of strength and conditioning research also found IMT benefitted interval running training (5).
Improved Sprint Interval recovery
Researchers have also found inspiratory muscle training to benefit recovery between sprint intervals (6).
Improved Cycling Performance
Respiratory training has also proved beneficial in cyclists.
Cycling Time trial Performance and Time to Exhaustion
In a study published in the Journal of Sports Science (7), 16 male cyclists (average VO2 max 64) improved 20 and 40k cycling time trial performance following IMT. They also improved respiratory muscle function and had a lower perception of respiratory and peripheral effort — a sign of reduced peripheral fatigue.
Other studies have also found IMT beneficial for improved cycling time-trial performance (8) and improved time to exhaustion (9). Interestingly, researchers suggest that one factor here may be improvements in anaerobic work capacity (8).
Improved Swimming Performance
Swimming is another sport that has proven to benefit from respiratory muscle training.
Significant effect on 100-400m swimming times
Here, both inspiratory training and a specific respiratory muscle warm up have benefitted 100 to 400m swimming performance.
When researchers introduced a specific inspiratory muscle exercise warm up, to the training programs of elite swimmers (2 sets of 30 breaths at 40% of maximum inspiratory mouth pressure), they significantly improved their 100m freestyle swimming performance (10).
It’s necessary to acknowledge that in a separate study involving elite swimmers, researchers failed to find a benefit from respiratory training (11). The researchers commented that swim training strengthens inspiratory muscles similarly to inspiratory muscle training; which may explain the lack of significant improvement in this study. In this case the elite swimmers probably needed a higher resistance level to gain the benefits of inspiratory muscle training.
What this does highlight is how effective swimming is for our respiratory muscles.
In another study (12) — this time using a block of inspiratory muscle training — a group of 16 club-level swimmers improved their 100, 200 and 400m swimming times.
It also proved beneficial for young swimmers (13).
Inspiratory Muscle Training is Beneficial for Athletes with Asthma
Given the positive effects on lung function and exercise performance, it should come of little surprise that it also benefits people with asthma. Here, the standard training approach (30 breaths at 50% MIP, completed twice daily) led to improvements in inspiratory muscle fatigue and increased exercise tolerance (14). The researchers suggested that this may help with asthma management and benefit exercise training.
What can we take from the research?
First, inspiratory muscle training benefits exercise performance in a range of sports.
Second, it benefits performance in short and longer term events — from 100m swimming to 40k cycling time trials. It’s also improves the effectiveness of key training sessions like aerobic intervals and repeated sprints.
Third, it’s beneficial when used as part of a pre-workout (or pre-competition) warm-up, and when used as specific training to improve respiratory muscle efficiency and strength. However, it appears to be more effective when we use both approaches.
How to use inspiratory muscle training?
Research has used the following approaches:
Inspiratory muscle training
30 resisted breaths (as one set), performed twice daily.
We can complete this every day of the week; although some studies have used a 5day training, 2day rest approach. Both approaches work, but the training itself is of low stress, so completing this daily is not an issue — this is my preferred approach.
Resistance is set to 50% of maximum inspiratory pressure (MIP). And most often researchers kept resistance at this intensity. You can also increase this progressively. As an example from 50, to 60, to 70, etc.
Researchers have found significant improvements occur after 4-6 weeks of training. Although my experience is that you notice improvements in inspiratory muscle strength after just 1-2weeks.
An approach I’ve employed is to split the 30 breaths into 3 sets of 10 and complete each at higher resistance.
Inspiratory muscle warm up
Here, researchers have mainly used a lower resistance (40-50% of MIP — most used 40%) completed as 1 or 2 sets of 30 breaths during the warm up for interval / more intense training, or before competitions.
In terms of training, I’ve only used this as part of respiratory strength training routine and haven’t yet tried this as part of a pre-workout warm up. But now i’ll be sure to include this before key training sessions.
- Inspiratory training involves resisted breath training to increase the strength, efficiency and fatigue resistance of your diaphragm.
- It works by reducing the effects of the metaboreflex — a phenomenon where your body actively reduces blood flow to the working muscles when your respiratory muscles fatigue.
- Respiratory muscle training increases respiratory muscle strength and function, and enhances exercise performance.
- It’s beneficial for several sports (running, cycling, swimming, etc) and for shorter and longer duration exercise. It may also benefit athletes with asthma.
- We can gain the benefits from specific respiratory training and also as part of a targeted warm-up routine — you gain greater benefits by using both approaches.
- Research suggests that training should involve 30 breaths at 50% MIP, completed twice daily. When using as a warm-up routine, aim for 30 breaths at 40% MIP as either one or two sets.
- Researchers have found benefits following 4-6 weeks of training.
- Swimming appears to strengthen respiratory muscles in a similar fashion to inspiratory muscle training.
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2) Chang YC, Chang HY, Ho CC, Lee PF, Chou YC, Tsai MW, Chou LW. Effects of 4-Week Inspiratory Muscle Training on Sport Performance in College 800-Meter Track Runners. Medicina (Kaunas). 2021 Jan 15;57(1):72. doi: 10.3390/medicina57010072. PMID: 33467421; PMCID: PMC7830231.
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