Exercise Interventions in Obstructive Sleep Apnea Syndrome

The Effect of Exercise Snacks and Aerobic Exercise on Circadian Rhythm and Functional Capacity in Individuals With Obstructive Sleep Apnea Syndrome

Obstructive Sleep Apnea Syndrome (OSA) is a condition characterized by repeated pauses or reductions in breathing during sleep, which can negatively affect sleep quality, daytime functioning, and physical capacity. Although regular exercise is known to have beneficial effects in OSA, the effects of different exercise approaches on circadian rhythm and functional capacity have not been sufficiently investigated.The primary aim of this study is to compare the effects of exercise snacking and aerobic exercise on circadian rhythm and functional capacity in individuals with OSA, in comparison with a control group. The secondary aim is to evaluate the effects of these exercise interventions on peripheral muscle strength, fatigue level, body composition, quality of life, and physical activity level.Participants will be randomly assigned to three groups: an aerobic exercise group, an exercise snacking group, and a control group. While the exercise groups will follow their respective intervention programs, the control group will continue their routine treatment.This study aims to answer whether exercise snacking, which consists of short bouts of exercise distributed throughout the day, may be an alternative or complementary approach to traditional aerobic exercise in individuals with OSA. In addition, this study aims to be the first randomized controlled trial evaluating the effects of exercise snacking on circadian rhythm and functional capacity in individuals with OSA.

Obstructive Sleep Apnea Syndrome (OSA) is a common sleep-related breathing disorder characterized by repeated episodes of partial or complete upper airway obstruction during sleep. It is associated with intermittent hypoxia, sleep fragmentation, and increased risk of cardiovascular and metabolic comorbidities. Emerging evidence also suggests a bidirectional relationship between OSA and circadian rhythm disruption, where each condition may negatively influence the other. Therefore, improving circadian regulation may be an important therapeutic target in OSA management.Exercise is a widely accepted non-pharmacological intervention in OSA due to its potential benefits on sleep-related outcomes and overall health. However, adherence to conventional structured exercise programs may be limited due to time constraints and sustainability issues. Recently, exercise snacking-short bouts of exercise performed throughout the day-has been proposed as a time-efficient and more feasible alternative to traditional exercise approaches. This strategy may improve long-term adherence by integrating physical activity into daily routines without requiring supervised sessions.Despite its potential advantages, evidence regarding the effects of exercise snacking in individuals with OSA is currently limited. In addition, there is a lack of randomized controlled trials comparing exercise snacking with aerobic exercise while also evaluating circadian rhythm-related outcomes in this population.This study is designed as a prospective, single-blind, randomized controlled trial. A total of 39 individuals diagnosed with moderate to severe OSA will be randomly assigned to three groups: aerobic exercise group, exercise snacking group, and control group. The intervention period will last 8 weeks. The aerobic exercise group will perform supervised aerobic and resistance-based training, while the exercise snacking group will perform short, home-based exercise bouts distributed across the day. The control group will continue usual medical care and receive a single session of sleep hygiene education.The study will evaluate the effects of the interventions on circadian rhythm and functional capacity as primary outcomes, and on secondary outcomes including fatigue, muscle strength, body composition, physical activity level, insomnia severity, and quality of life. Assessments will be performed at baseline and after the 8-week intervention period.

Inclusion Criteria:

• Individuals diagnosed with OSAHS (AHI ≥ 15) confirmed by polysomnography, with moderate or severe disease, who have been receiving CPAP therapy for at least 3 months.
• Adults aged 30-65 years.
• No participation in any regular exercise program within the last 6 months.

Exclusion Criteria:

• Individuals with OSAHS and a body mass index (BMI) > 35 kg/m²
• Severe chronic pulmonary disease
• Neurological or musculoskeletal disorders that prevent exercise
• Unstable cardiovascular conditions
• Unstable metabolic conditions
• Severe psychiatric disorders such as bipolar disorder or schizophrenia
• Pregnancy or breastfeeding
• Individuals working night shifts or with schedules that may cause jet lag
• Use of steroid or hormone therapy
• Use of melatonin or sleep-regulating medications within the last 3 months
• Presence of acute infection or inflammation