This new study investigates the effects of inspiratory muscle training (IMT) on smokers and non-smokers. Researchers from Ondokuz Mayıs University and Gaziantep University in Turkey look into how IMT may affect pulmonary function and respiratory muscle strength in both these groups.
Pulmonary function & respiratory muscle strength
Pulmonary function indicates how well a person’s lungs are working to help them breathe. There are different tests that measure pulmonary function, otherwise known as lung function.
Respiratory muscle strength is an indication of how much pressure the breathing muscles generate when a person breathes in or out. Assessment of respiratory muscle strength involves measuring MIP or MEP. MIP or maximal inspiratory pressure reflects the strength of the inspiratory muscles, such as the diaphragm. Meanwhile MEP or maximal expiratory pressure reflects the strength of the expiratory muscles.
The IMT program
For the IMT program, subjects use the POWERbreathe Classic IMT device. The procedure consists of 30 x 2 dynamic inspiratory efforts with a 1-minute interval. They perform this for four weeks, seven days a week. The reason researchers chose this procedure is that it has been previously applied in healthy individuals.
Smokers group, non-smokers & placebo groups
Forty-two healthy males enrol in this randomised, double-blind, placebo-controlled experimental design study. There are 16 subjects in the IMT smokers group (IMTS), 16 in the IMT non-smokers group (IMTN) with the final 10 subjects in the placebo group. This final group receive a sham ‘placebo’ treatment that will have no real effect.
By using a double-blind, placebo-controlled experimental design study, researchers can test out a therapy. The placebo treatment will feel just like the actual treatment, in this case, IMT. The reason for this is so that both the subject and the researcher’s expectations will not affect the outcome. Furthermore, a double-blind controlled study means that neither the researchers nor the subjects taking part know who will be receiving which treatment. This is vital in helping to avoid bias when measuring outcomes.
For the study, the experimental groups (IMTS and IMTN) perform POWERbreathe IMT at 50% of maximal inspiratory pressure. Researchers increase this each week. Meanwhile, in the placebo group, subjects perform POWERbreathe IMT at only 15% of MIP.
Improvements occur in smokers after IMT
Results of the study show significant improvements in respiratory muscle strength and pulmonary functions after the 4-week POWERbreathe IMT program. Even more promising is the fact that improvements in smokers are greater. Potentially, this is a result of a:
“greater influence of exercise on smokers’ lung microbiome in reversing the negative effects of smoking.”
For smokers, this means that their stronger inspiratory muscles will improve their ability to breathe in more air, for longer and with less fatigue. This will have a positive impact on daily life by helping them improve their ability to perform daily activities that may have been prohibitive before.