RecruitingNot ApplicableNCT06807957

Inspiratory Muscle Training in Amateur CrossFit® Athletes

Effectiveness of Inspiratory Muscle Training on Respiratory Muscle Strength and Physical Performance in Amateur CrossFit® Athletes: A Randomized Controlled Trial

Sponsor

Federal University of the Valleys of Jequitinhonha and Mucuri

Enrollment

94 participants

Start Date

Jan 1, 2026

Study Type

INTERVENTIONAL

Conditions

Healthy

Summary

The aim of this randomized controlled trial is to investigate the effectiveness of inspiratory muscle training (IMT) on the performance of athletes in CrossFit® activities, respiratory muscle strength, and perceived post-training fatigue. This study follows a two-arm randomized controlled trial protocol. Ninety-four volunteers aged between 18 and 60 years, enrolled in CrossFit® training, will be randomly allocated to the IMT Group, which involves respiratory training using a linear load device (Powerbreathe®) in conjunction with CrossFit® training; or the Non-IMT Group, which undergoes the same training as the intervention group but uses a device without a valve that ensures resistance. The primary outcome is to investigate the effectiveness of IMT: on maximum inspiratory pressure and maximum expiratory pressure. The secondary outcomes include performance in the six-minute walk test, Pistol, Burpee, Sit-up, Box Jump, Thruster, and Single-Under, burning 25 calories on the "Air Bike" measured by the time taken to reach the 25-calorie mark on this equipment, as well as the assessment of subjective fatigue perception. All outcomes of interest will be collected at baseline and reassessed: mid-term (8 weeks after allocation); and long-term (12 weeks after allocation), the IMT and MEP will be reassessed. Analyses will follow the intention-to-treat principle. Treatment effects will be assessed using Linear Mixed Models. The results of this study may help clarify the effects of IMT on CrossFit® athletes.

Eligibility

Min Age: 18 YearsMax Age: 60 Years

Inclusion Criteria3

Age between 18 and 60 years;
Be enrolled in a CrossFit® program;
Be available to perform TMI at home 5 days a week.

Exclusion Criteria4

Have any musculoskeletal, cardiovascular and/or neurological condition that prevents CrossFit® and/or IMT from being performed;
Be a smoker;
Not sign the Termo de Consentimento Livre Esclarecido (TCLE);
Be performing or have performed IMT using linear load equipment in the last month.

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Interventions

DEVICEGroup with IMT

Group with IMT + CrossFit training

BEHAVIORALCrossFit® Training

The training routine will occur seven days a week, with participants encouraged and motivated to attend at least five training sessions. CrossFit® classes will include: warm-up exercises, strength training (with a focus on Olympic weightlifting and free weights), strength endurance (body weight and external loads), aerobic capacity (across multiple domains), maximal aerobic power (across multiple domains), anaerobic capacity (across multiple domains), cool-down activities, and mobility exercises. Each training session will be designed and supervised by a team of certified physical educators.