High-intensity exercise is essential for optimal development of cardiorespiratory fitness and health. This is, however, challenging for most people with chronic obstructive pulmonary disease (COPD) due to ventilatory limitations, leading to exercise at lower intensities accompanied by suboptimal stress on the cardiovascular and muscular system. The aims of this cross-over trial is: 1. To compare the acute effects of short-duration supramaximal high-intensity interval training (HIIT) vs. traditional moderate-intensity continuous training (MICT) in people with COPD and matched healthy controls (HC). 2. To investigate the feasibility of supramaximal HIIT in people with COPD and matched HC. 3. To compare the cardiorespiratory demand, exercise intensity and symptoms during a modified Borg Cycle Strength Test (BCST) and a cardiopulmonary exercise test (CPET) in people with COPD and HC.
In this study, eligible participants attended the facility four times within 14 days with at least 48 hours of rest between visits. Exercise tests (visit 1, week 1): After pulmonary functions tests, a CPET on a stationary bicycle was performed according to international guidelines. After 1.5 hours of recovery, a BCST was performed to assess anaerobic exercise capacity and determine exercise intensities for supramaximal HIIT. Exercise sessions (visit 2 - week 1; visit 3 - week 2; visit 4 - week 2): The order of the two first exercise sessions (HIIT at 60% of MPO6 or MICT) on a stationary bicycle were randomized. The exercise session at HIIT at 80% of MPO6 was always the third exercise session. During all exercise sessions, blood collection was performed at baseline after a 15-minute seated rest. During HIIT, blood was collected immediately after, and 30 minutes after the 10-minute HIIT period. For MICT, blood was collected after 10 minutes (isotime in relation to HIIT), immediately after, and 30 minutes of cycling at 60% MAP.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
NONE
Enrollment
32
Supramaximal HIIT is performed as 10×6 second intervals against a load of 60% of maximum mean power output for 6 seconds (MPO6) with a 54 second recovery between intervals. The MPO6 was estimated from the BCST. Duration supramaximal HIIT: 10 minutes Warm-up and cool-down: 5 minutes at 30% of maximum aerobic power (MAP) obtained during maximal incremental cardiopulmonary exercise test (CPET) on a stationary bicycle.
MICT is performed against a load of 60% of MAP obtained during a maximal incremental CPET on a stationary bicycle. Duration MICT: 20 minutes Warm-up and cool-down: 5 minutes at 30% of MAP obtained during maximal incremental CPET on a stationary bicycle.
Supramaximal HIIT is performed as 10×6 second intervals against a load of 80% of MPO6 with a 54 second recovery between intervals. The MPO6 was estimated from the BCST. Duration supramaximal HIIT: 10 minutes Warm-up and cool-down: 5 minutes at 30% of MAP obtained during maximal incremental CPET on a stationary bicycle.
Umeå University
Umeå, Sweden
Exercise intensity
Produced watt at the set training intensity
Time frame: During visit 2 (week 1)
Exercise intensity
Produced watt at the set training intensity
Time frame: During visit 3 (week 2)
Exercise intensity
Produced watt at the set training intensity
Time frame: During visit 4 (week 2)
Brain-derived neurotrophic factor (BDNF)
Concentration of BDNF in obtained venous blood samples before, during and after exercise. Measured as ng/mL or pg/mL.
Time frame: During visit 2 (week 1)
Brain-derived neurotrophic factor (BDNF)
Concentration of BDNF in obtained venous blood samples before, during and after exercise. Measured as ng/mL or pg/mL.
Time frame: During visit 3 (week 2)
Brain-derived neurotrophic factor (BDNF)
Concentration of BDNF in obtained venous blood samples before, during and after exercise. Measured as ng/mL or pg/mL.
Time frame: During visit 4 (week 2)
Cardiorespiratory demand
Gas exchange parameters (e.g. VO2, VCO2, ventilatory equivalents, RER) and lung volumes (e.g. VE, Vt, breathing frequency) obtained with a metabolic cart (breath by breath methodology) and heart rate (beats per minutes) during exercise during exercise.
Time frame: During visit 1 (CPET and BCST; week 1), visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Venous blood lactate concentration
Measured before, during and after exercise.
Time frame: During visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Rating of perceived exertion
Rating of perceived exertion scale (Borg RPE). Minimum value = 6 Maximum value = 20 A higher score means higher exertion.
Time frame: During visit 1 (CPET and BCST; week 1), visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Rating of symptoms
Rating of dyspnea and leg fatigue symptoms via Borg CR (category ratio) 10 during exercise Minimum value = 0 Maximum value = 10 A higher score means higher severity of symptoms
Time frame: During visit 1 (CPET and BCST; week 1), visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Peripheral blood oxygen saturation (SpO2)
SpO2 during exercise
Time frame: During visit 1 (CPET and BCST; week 1), visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Blood pressure
Systolic and diastolic blood pressure during exercise
Time frame: During visit 1 (CPET and BCST; week 1), visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Circulating levels of neurotrophic factors
Plasma or serum concentration (measured as mg/l, ng/l, or pq/l) of irisin, cathepsin B, clusterin, in obtained venous blood samples before, during and after exercise.
Time frame: During visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Circulating levels of exerkines
Plasma or serum concentration of interleukin (IL)-1b, IL-4, IL-6, IL-8, IL-10, IL-13, IL-15, IL-17, tumor necrosis factor (TNF)-α, vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF), and adiponectin in obtained venous blood samples before, during and after exercise.
Time frame: During visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Exercise session completion
Number of uninterrupted exercise sessions
Time frame: During visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Exercise preference
Preference for HIIT at 60% of MPO6 or MICT, defined as answer on the following question: "If the MICT and HIIT would be equally effective in improving your health and physical capacity, which one would you prefer to perform?"
Time frame: At the end of visit 3 (week 2)
Session RPE
Rating of session RPE on Borg CR (category ratio) 10 is assessed 30 min after every exercise session Minimum value = 0 Maximum value = 10 A higher score means higher session exertion
Time frame: During visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
Exercise capacity
Maximal aerobic power (MAP) expressed as produced watt at VO2peak
Time frame: During visit 1 (CPET; week 1)
Exercise intensity
Maximum mean power output for 30 seconds (MPO30) in watts
Time frame: During visit 1 (BCST; week 1)
Adverse events
Occurence and severity of adverse events. The severity of adverse events will be assessed and rated into four different categories: 1) minor and temporary, 2) serious symptoms (potential risk of severe injury or life threatening, 3) manifest injury or disease and 4) death. An adverse event rate will be calculated for each participant as the total number of sessions during which any adverse events occurred divided by the total number of attended sessions.
Time frame: During visit 2 (week 1), visit 3 (week 2) and visit 4 (week 2)
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