Physiological adaptations to inspiratory muscle training

Summary

Young, healthy females and males will complete three identical blocks comprised of two testing days per block. After a baseline block, there will be an initial 8-week no-training period followed by 8 weeks of inspiratory muscle training.

Day 1: You will fill out a health questionnaire and test your breathing/lungs to ensure you're healthy. Next, you will complete a maximal exercise test on a stationary bike to fatigue. This test will determine your aerobic fitness and strength of your breathing muscles. After resting, you will briefly cycle again and breath higher carbon dioxide than normal. This will increase breathing rates above normal levels to test how much you can breathe. After, will practice the test done in Visit 2.

Day 2: You will exercise your breathing muscles several times. We will measure how much blood goes to the breathing muscles during progressive exercise. To do this, we will inject microbubbles into your blood and image your diaphragm with an ultrasound. That allows us to measure how much blood is going to the diaphragm.

During both visits, we will insert a thin tube in your nose and place it in the esophagus and another in the stomach. The end of the tube contains a small air sac that will measure the force you breath with.

Inspiratory muscle training will consist of 30 breaths done 2x/day for 5 days/week for 8 weeks. The strength of the respiratory muscles will retested every 2 weeks. Participants will repeat testing following 8-weeks of no training and training.