The goal of this clinical trial is to evaluate the impact of supervised training program on body composition, muscular strenght, insulino-resistance profile, heart rate variability and on heart structure and function between 3 to 6 months after mixed bariatric surgery or restrictive bariatric surgery. This study will be conducted in men and women with severe obesity. Respectively for each type of surgery (mixed vs. restrictive), participants will be randomized either to the exercise group or to the control group. For participant randomized in the exercise group, 3 months after the bariatric surgery, they will started a supervised exercise program for 3 months. In contrast, for participant randomized in the control group, they will have consultation with kinesiologist to receive general information about physical activity practice. Each participants will perform 4 evaluations; one before bariatric surgery and 3 after bariatric surgery (3 months, 6 months and 12 months). Thoses evaluations will be assessed at each visit : fasting blood draw, anthropometric measurements, cardiac echocardiography, heart rate variability measurement, mid-thigh and abdominal computed tomography scan, maximal exercise test, six-minute walk test, assessment of lower-limb endurance and strength, assessment of physical activity level and energy expenditure.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
61
The exercise program will take place at the Pavillon de Prévention des Maladies Cardiaques, following a personalised exercise program with at least 3 scheduled 60-minute training sessions every week. The ACSM certified kinesiologist in charge of patients will adjust the progression of patients programs on a weekly basis, based on their needs. Length and intensity of training will increase in the first three weeks. The first week will have 20 minutes of cardio (40-60% reserve heart rate) and 10 minutes of muscle training (2 series of 10-15 repetitions). The second week will have a 30 minutes of cardio and 15 minutes of muscle training (2 series of 10-15 repetitions). The third week will have 35 minutes of cardio (50-75% reserve heart rate) and 25 minutes of muscle training (3 series of 10-15 repetitions).
Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval
Québec, Quebec, Canada
Change in abdominal adipose tissue (visceral) as measured by computed tomography (cm2)
Change in abdominal adipose tissue (visceral adipose tissue) as measured by computed tomography (Siemens Somaton DRH). Image acquisition will follow a voltage between 120 and 140 kV (according to the subject's weight), a fixed tube current-time product set at 250 mAs, and a slice thickness of 10 mm. For the evaluation, subjects will be in the supine position with their arms extended above their head. CT will be performed at two locations. Midpoint between L2-L3; Midpoint between L4-L5. Analysis of the CT images will be performed using sliceOmatic 4.3 Rev-6f software. Resulting measurement unit is in cm2.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Change in abdominal adipose tissue (subcutaneous) as measured by computed tomography (cm2)
Change in abdominal adipose tissue (subcutaneous adipose tissue) as measured by computed tomography (Siemens Somaton DRH). Image acquisition will follow a voltage between 120 and 140 kV (according to the subject's weight), a fixed tube current-time product set at 250 mAs, and a slice thickness of 10 mm. For the evaluation, subjects will be in the supine position with their arms extended above their head. CT will be performed at two locations. Midpoint between L2-L3; Midpoint between L4-L5. Analysis of the CT images will be performed using sliceOmatic 4.3 Rev-6f software. Resulting measurement unit is in cm2.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Change in thigh muscle tissue (normal density) as measured by computed tomography (cm2)
Change in thigh normal density muscle tissue as measured by computed tomography (Siemens Somaton DRH). Image acquisition will follow a voltage between 120 and 140 kV (according to the subject's weight), a fixed tube current-time product set at 250 mAs, and a slice thickness of 10 mm. For the evaluation, subjects will be in the supine position with their arms extended above their head. At each visit, CT will be performed at the midpoint between iliac crest and tibial plateau. Analysis of the CT images will be performed using sliceOmatic 4.3 Rev-6f software. Resulting measurement unit is in cm2.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Change in thigh adipose tissue (subcutaneous) as measured by computed tomography (cm2)
Change in thigh subcutaneous adipose tissue as measured by computed tomography (Siemens Somaton DRH). Image acquisition will follow a voltage between 120 and 140 kV (according to the subject's weight), a fixed tube current-time product set at 250 mAs, and a slice thickness of 10 mm. For the evaluation, subjects will be in the supine position with their arms extended above their head. At each visit, CT will be performed at the midpoint between iliac crest and tibial plateau. Analysis of the CT images will be performed using sliceOmatic 4.3 Rev-6f software. Resulting measurement unit is in cm2.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Change in thigh adipose tissue (deep) as measured by computed tomography (cm2)
Change in thigh deep adipose tissue as measured by computed tomography (Siemens Somaton DRH). Image acquisition will follow a voltage between 120 and 140 kV (according to the subject's weight), a fixed tube current-time product set at 250 mAs, and a slice thickness of 10 mm. For the evaluation, subjects will be in the supine position with their arms extended above their head. At each visit, CT will be performed at the midpoint between iliac crest and tibial plateau. Analysis of the CT images will be performed using sliceOmatic 4.3 Rev-6f software. Resulting measurement unit is in cm2.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Muscular strength (upper-limb) assessed through handgrip via maximal voluntary contraction (kg)
Muscular upper-limb strength will be assessed with handgrip strength will be measured using a hydraulic hand dynamometer in kg, following the "Société canadienne de physiologie à l'exercice" protocol, as an indicator of upper-limb strength and functional capacity.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Muscular relative strength (upper-limb) assessed through handgrip via maximal voluntary contraction (ratio)
Muscular upper-limb strength (relative) will be assessed with handgrip strength, measured using a hydraulic hand dynamometer in kg divided by weight (kg), following the "Société canadienne de physiologie à l'exercice" protocol, as an indicator of upper-limb strength and functional capacity.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Muscular strength (lower-limb) assessed through the femoral quadriceps via maximal voluntary contraction (Nm)
Lower-limb strength will be evaluated via maximal voluntary contraction and muscular fatigue of the femoral quadriceps using an isokinetic dynamometer (Biodex System 4 Pro, Shirley, NY). After a familiarization session, participants will perform a series of maximal concentric contractions (30 repetitions at 60°/s) to assess isokinetic strength and fatigue, followed by isometric maximal voluntary contractions at a fixed knee angle (80°) held for 4 seconds and repeated three times. Measurements will be conducted bilaterally under standardized positioning and stabilization conditions, with consistent range of motion across all time points. Strength is measured in Nm.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Muscular relative strength (lower-limb) assessed through the femoral quadriceps via maximal voluntary contraction (Nm/kg)
Lower-limb strength will be evaluated via maximal voluntary contraction and muscular fatigue of the femoral quadriceps using an isokinetic dynamometer (Biodex System 4 Pro, Shirley, NY). After a familiarization session, participants will perform a series of maximal concentric contractions (30 repetitions at 60°/s) to assess isokinetic strength and fatigue, followed by isometric maximal voluntary contractions at a fixed knee angle (80°) held for 4 seconds and repeated three times. Measurements will be conducted bilaterally under standardized positioning and stabilization conditions, with consistent range of motion across all time points. Strength is measured in Nm and divided by weight (kg).
Time frame: Before surgery and 3, 6 and 12 months post surgery
Change in insulin resistance (HOMA-IR)
Insulin resistance will be determined using the Homeostatic Model Assessment of insulin resistance (HOMA-IR), calculated as follows: fasting insulin (μU/mL) × fasting glucose (mmol/L) / 22,518.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Cardiac structure - Left ventricular mass (absolute) as assessed by transthoracic echocardiogram (g)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Cardiac structure - Left ventricular mass (relative) as assessed by transthoracic echocardiogram (g/m2)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Cardiac function - Diastolic function as assessed by transthoracic echocardiogram (function/dysfunction, 1 to 3 dysfunction grade scale)
Cardiac function is assessed through diastolic function. Diastolic function is assessed as being functional or dysfunctional. If dysfunctional, the dysfunction is graded on the scale of 1 to 3. A reduction in dysfunction equals to a lowering of the dysfunction grade or complete remission of prior dysfunction. Diastolic dysfunction presence and grade is determined with multiple parameters.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Time (SDNN) as assessed by a 24-hour Holter (ms)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Time (SDRR) as assessed by a 24-hour Holter (ms)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Time (SDANN) as assessed by a 24-hour Holter (ms)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Time (pNN50) as assessed by a 24-hour Holter (ms)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Time (RMSSD) as assessed by a 24-hour Holter (ms)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Frequency (VLF power) as assessed by a 24-hour Holter (ms2)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. Very low frequency (VLF: 0.0033-0.04 Hz), reflecting parasympathetic, neuroendocrine, and thermogenic activity will be analyzed.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Frequency (LF power) as assessed by a 24-hour Holter (ms2)
Description: The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. Low frequency (LF: 0.04-0.15 Hz), reflecting both sympathetic and parasympathetic activity will be analyzed. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Frequency (HF power) as assessed by a 24-hour Holter (ms2)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. High frequency (HF: 0.15-0.4 Hz), reflecting parasympathetic activity, will be analyzed. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate Variability - Frequency (LF/HF) as assessed by a 24-hour Holter (ratio)
The 24-hour recording will be divided into three periods: (1) the full 24-hour period, (2) the daytime period (8:00 AM to 8:00 PM), and (3) the nighttime period (12:00 AM to 6:00 AM). The nighttime period may vary according to individual differences in sleep and wake times. The LF/HF ratio will be used to assess sympathovagal balance. For the entire recording, a technician will remove artifacts around QRS complexes.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Functional capacity using the 6MWT - Total distance walked (m)
All mentions of "6MWT" (6-minute walk test) in this study refers to the following description. The 6-minute walk test (6MWT) will be administered to all participants in both groups according to the American Thoracic Society guidelines. It will assess functional capacity and its changes over the course of the study. After standardized instructions, participants will be asked to walk as far as possible (without running or jumping) for six minutes. The test will take place in a corridor marked by two cones placed 30 meters apart. It will be administered by an ACSM-certified Clinical Exercise Specialist and supervised by a physician. During the test, participants will wear a portable system (≤2 kg) including a 12-lead electrocardiogram, a pulse oximeter, and a gas analyzer. Functional capacity is measured in total meters walked.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - Weight relative VO2peak (mL/kg/min)
Aerobic capacity is measured with the weight relative VO2peak (mL/kg/min) during the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - Fat-free mass relative VO2peak (mL/kg/min)
Aerobic capacity is measured with the fat-free mass relative VO2peak (mL/kg/min) during the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - Absolute VO2peak (mL/min)
Aerobic capacity is measured with the absolute VO2peak (mL/min) during the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Physical activity measurement - Total energy expenditure as assessed by an armband monitor (kcal)
A portable, wireless armband monitor (SenseWearPro2) will be used to measure energy expenditure. The armband will be worn for three consecutive days, including two weekdays and one weekend day. Participants will wear the device from waking until bedtime. The armband will not provide any feedback to the participant. The armband includes a biaxial accelerometer and multiple sensors used to estimate total energy expenditure. The accelerometer measures linear acceleration and deceleration of the body along horizontal and vertical axes. A heat flux sensor records heat dissipation to help differentiate activities. A skin temperature sensor measures skin temperature while accounting for ambient conditions. A galvanic skin response sensor measures skin impedance, reflecting its water content. Data is processed using proprietary alogirthms via the armband's software.
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Time frame: Before surgery and 3, 6 and 12 months post surgery
Functional capacity using the sit-to-stand test (rep)
A sit-to-stand test will be performed. It will be used to assess functional capacity as well as lower-limb strength and endurance. Seated on a chair approximately 45-50 cm in height, with feet flat on the floor at shoulder width and arms crossed over the chest, participants will be asked to stand up and sit down as many times as possible over a continuous 30-second period (rep). Prior to the test, participants may perform one to two practice repetitions. The sit-to-stand test is associated with stair-climbing ability and walking speed and is a safe and sensitive tool to detect improvements in functional capacity resulting from an exercise program.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Sodium (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Urea (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Creatinine (µmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - EGFR (mL/min/1,73m2)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Glucose (mmol/l)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Insulin (pmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Glycated hemoglobin (HbA1c; %)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - High-density lipoproteins (HDL; mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Low-density lipoproteins (LDL; mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Total cholesterol (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Triglycerides (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Apolipoprotein B (g/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Calcium (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Magnesium (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Phosphate (U/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Parathyroid hormone (TSH; mU/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Vitamin A (µmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anthropometric measures - Body weight (kg)
Body composition will be assessed using a Tanita bioelectrical impedance scale, providing a measure of body weight in kg.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anthropometric measures - Body fat (%)
Body composition will be assessed using a Tanita bioelectrical impedance scale, providing a measure of body fat as a percentage.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Physical activity measurement - Total physical activity duration as assessed by an armband monitor (minutes)
A portable, wireless armband monitor (SenseWearPro2) will be used to measure physical activity levels. The armband will be worn for three consecutive days, including two weekdays and one weekend day. Participants will wear the device from waking until bedtime. The armband will not provide any feedback to the participant. The armband includes a biaxial accelerometer and multiple sensors used to estimate to estimate the duration and intensity of physical activity The accelerometer measures linear acceleration and deceleration of the body along horizontal and vertical axes. A heat flux sensor records heat dissipation to help differentiate activities. A skin temperature sensor measures skin temperature while accounting for ambient conditions. A galvanic skin response sensor measures skin impedance, reflecting its water content. Data is processed using proprietary algorithms via the armband's software. Total physical activity duration (\>1.5 METs)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Physical activity measurement - Total light physical activity duration as assessed by an armband monitor (minutes)
A portable, wireless armband monitor (SenseWearPro2) will be used to measure physical activity levels. The armband will be worn for three consecutive days, including two weekdays and one weekend day. Participants will wear the device from waking until bedtime. The armband will not provide any feedback to the participant. The armband includes a biaxial accelerometer and multiple sensors used to estimate to estimate the duration and intensity of physical activity The accelerometer measures linear acceleration and deceleration of the body along horizontal and vertical axes. A heat flux sensor records heat dissipation to help differentiate activities. A skin temperature sensor measures skin temperature while accounting for ambient conditions. A galvanic skin response sensor measures skin impedance, reflecting its water content. Data is processed using proprietary algorithms via the armband's software. Total light physical activity duration (1.5 to 2.9 METs).
Time frame: Before surgery and 3, 6 and 12 months post surgery
Physical activity measurement - Total moderate-to-vigorous physical activity duration as assessed by an armband monitor (minutes)
A portable, wireless armband monitor (SenseWearPro2) will be used to measure physical activity levels. The armband will be worn for three consecutive days, including two weekdays and one weekend day. Participants will wear the device from waking until bedtime. The armband will not provide any feedback to the participant. The armband includes a biaxial accelerometer and multiple sensors used to estimate to estimate the duration and intensity of physical activity The accelerometer measures linear acceleration and deceleration of the body along horizontal and vertical axes. A heat flux sensor records heat dissipation to help differentiate activities. A skin temperature sensor measures skin temperature while accounting for ambient conditions. A galvanic skin response sensor measures skin impedance, reflecting its water content. Data is processed using proprietary algorithms via the armband's software. Total moderate-to-vigorous physical activity duration (≥3.0 METs)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anthropometric measures - Lean mass (kg)
Body composition will be assessed using a Tanita bioelectrical impedance scale, providing a measure of lean mass in kg.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anthropometric measures - Fat mass (kg)
Body composition will be assessed using a Tanita bioelectrical impedance scale, providing a measure of fat mass in kg.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anthropometric measures - Body water (kg)
Body composition will be assessed using a Tanita bioelectrical impedance scale, providing a measure of body water in kg.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anthropometric measures - BMI (kg/m²)
Body mass index (BMI) will be calculated as weight in kilograms divided by height in meters squared (kg/m²). Participants' height will be measured using a stadiometer (cm).
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anthropometric measures - Waist circumference (cm)
Waist circumference will be measured at the level of the iliac crests using a flexible measuring tape (cm).
Time frame: Before surgery and 3, 6 and 12 months post surgery
FVC as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (L)
The following description apllies to all outcomes mentioning "maximal graded exercise test". The test uses a ramp protocol on an electromagnetically braked recumbent cycle ergometer. Participants breathe through a mouthpiece connected to a gas analyzer. A 12-lead EKG will monitor cardiac activity, and a pulse oximeter will measure blood oxygen saturation. Perceived exertion using the modified Borg scale and BP will be measured every two minutes. After three minute of resting, then one minute of unloaded pedaling, workload will increase at a rate of 15 to 30 watts per minute, until maximal fatigue is reached or one or more termination criteria are met. The test is expected to last between eight and twelve minutes, with an ideal workload increment corresponding to 10% of the individual's maximal oxygen consumption per minute and a pedaling cadence between 60 and 120 revolutions per minute. Forced Vital Capacity (FVC) will be measured before the test, in L.
Time frame: Before surgery and 3, 6 and 12 months post surgery
FEV1 as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (L)
Forced expiratory volume in one second (FEV1) will be measured before the maximal graded exercise test, in L.
Time frame: Before surgery and 3, 6 and 12 months post surgery
MVV as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (L/min)
Maximal voluntary ventilation (MVV) will be measured before the maximal graded exercise test, in L/min.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anaerobic threshold VO2 (weight relative VO2) as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (mL/kg/min)
Multiple measures will help determine the anaerobic threshold (AT) during the maximal graded exercise test. The Weight relative VO2 (mL/kg/min) will be examined at the AT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anaerobic threshold VO2 (fat-free mass relative VO2) as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (mL/kg/min)
Multiple measures will help determine the anaerobic threshold (AT) during the maximal graded exercise test. The fat-free mass relative VO2 (mL/kg/min) will be examined at the AT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anaerobic threshold VO2 (absolute VO2) as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (mL/min)
Multiple measures will help determine the anaerobic threshold (AT) during the maximal graded exercise test. The absolute VO2 (mL/min) will be examined at the AT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anaerobic threshold VE as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (L/min)
Multiple measures will help determine the anaerobic threshold (AT) during the maximal graded exercise test. The ventilation (VE; L/min) will be examined at the AT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anaerobic threshold RER as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (ratio)
Multiple measures will help determine the anaerobic threshold (AT) during the maximal graded exercise test. The respiratory exchange ratio (RER; ratio) will be examined, calculated as VCO2/VO2, at the AT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anaerobic threshold work load as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (Watts)
Multiple measures will help determine the anaerobic threshold (AT) during the maximal graded exercise test. The work load (Watts) will be examined at the AT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Anaerobic threshold heart rate as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (bpm)
Multiple measures will help determine the anaerobic threshold (AT) during the maximal graded exercise test. The heart rate (bpm) will be examined at the AT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Maximal aerobic capacity (weight relative VO2peak) as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (mL/kg/min)
Multiple measures will help determine the weight relative VO2peak (mL/kg/min) during the maximal graded exercise test.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Maximal aerobic capacity (absolute VO2peak) as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (mL/min)
Multiple measures will help determine the absolute VO2peak (mL/min) during the maximal graded exercise test.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Maximal aerobic capacity (fat-free mass relative VO2peak) as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (mL/kg/min)
Multiple measures will help determine the fat-free mass relative VO2peak (mL/kg/min) during the maximal graded exercise test.
Time frame: Before surgery and 3, 6 and 12 months post surgery
RER at VO2peak as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (ratio)
Multiple measures will help determine the VO2peak during the maximal graded exercise test, where respiratory exchange ratio (ratio), calculated as VCO2/VO2, will be examined.
Time frame: Before surgery and 3, 6 and 12 months post surgery
VE at VO2peak as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (ratio)
Multiple measures will help determine the VO2peak during the maximal graded exercise test, where ventilation (VE; L/min), will be examined.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Work load at VO2peak as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (Watts)
Multiple measures will help determine the VO2peak during the maximal graded exercise test, where work load (Watts), will be examined.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Heart rate at VO2peak as measured during a maximal graded exercise test using a ramp protocol on an cycle ergometer (bpm)
Multiple measures will help determine the VO2peak during the maximal graded exercise test, where Heart rate (bpm), will be examined.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - Absolute VO2 (mL/min) at 0%, 25%, 50%, 75%, 100% of the test.
Aerobic capacity is measured with the absolute VO2 (mL/min) at 0%, 25%, 50%, 75%, 100% of the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - Fat-free mass relative VO2 (mL/kg/min) at 0%, 25%, 50%, 75%, 100% of the test.
Aerobic capacity is measured with the fat-free mass relative VO2 (mL/kg/min) at 0%, 25%, 50%, 75%, 100% of the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - Weight relative VO2 (mL/kg/min) at 0%, 25%, 50%, 75%, 100% of the test.
Aerobic capacity is measured with the weight relative VO2 (mL/kg/min) at 0%, 25%, 50%, 75%, 100% of the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - VE (L/min) at the VO2peak.
Aerobic capacity is measured with the ventilation (VE; L/min) at the VO2peak of the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - RER (ratio) at the VO2peak.
Aerobic capacity is measured with the respiratory exchange rate (ration) at the VO2peak of the 6MWT, calculated as VCO2/VO2.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Aerobic capacity using the 6MWT - Heart rate (bpm) at the VO2peak.
Aerobic capacity is measured with the heart rate (bpm) at the VO2peak of the 6MWT.
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Vitamin B12 (pmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Vitamin D (nmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Potassium (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery
Biomarkers - Chloride (mmol/L)
Time frame: Before surgery and 3, 6 and 12 months post surgery