The study aims to investigate the effects of post-exercise and pre-sleep ketosis via oral ketone ester supplementation on physical and mental recovery during a multi-day cycling stage race.
Ultra-endurance events are becoming increasing popular. Participation in the multi-day events adds a lot of physical and mental strain on the body, while the athletes are still required to perform. Without appropriate recovery the athletes are at increased risk of overreaching, injury, or illness. Therefore, the purpose of the study is to create a better understanding of the exercise fatigue experienced during ultra-endurance performance and the role intermittent exogenous ketosis (IEK) plays in reducing the amount of fatigue to maintain performance during multi-day racing and lower the risk of injury and illness. Participants will first compete in a 8-day simulated stage race performed on taxc trainers and then we will conduct a field study during the Absa Cape Epic a 8-day mountain bike stage race. Immediately following each stage and 30-mins before bed the participants will consume either a ketone ester and taste-match placebo drink. During the race the following variables will be measured; hydration status, weight change, activity readiness, and nutrition intake. Cognitive function will be assessed on day 2, 4 and 8 of racing. One day before and one day after the race the participants will report to the lab to assess basal metabolic rate, stress via questionnaires, appetite, cognitive function, muscle biopsies, venous blood samples, mechanical efficiency and 30-min Time Trial.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
BASIC_SCIENCE
Masking
DOUBLE
Enrollment
24
Placebo supplement: Oral supplement containing: 16.4 grams of medium chained triglycerides, 1mM or sucrose octaacetate and water
Ketone ester supplement Oral supplement containing: 25 grams of pure (R)-3-hydroxybutyl-(R)-3-hydroxybutyrate ketone monoester drink
KU Leuven
Leuven, Vlaams-Brabant, Belgium
RECRUITINGMuscle soreness
Visual analog scale (0-10) How sore does you leg muscles feel? The VAS was used as a subjective measure of muscle soreness
Time frame: During the intervention
Physical stress
RESTQ-76 sport questionnaire was used to assess the stress-recovery balance
Time frame: pre-intervention and 1 day after the intervention
Hydration status
Before every stage, the participants provided a urine sample in a cup. A urine-specific refractometer (Atago) was used to determine their hydration status
Time frame: Baseline, During the intervention and 1 day after the intervention
Cognitive function: reaction time
CANTAB test battery reaction time test was used to determine reaction time in milliseconds.
Time frame: Pre-intervention, day 2, 4 and 8 of the intervention
Cognitive function: rapid visual processing
CANTAB test battery rapid visual processing test was used to assess their susceptibility to false alarms
Time frame: Pre-intervention, day 2, 4 and 8 of the intervention
Cognitive function: swm
CANTAB spatial working memory test was used to access executive function; the main outcome measure used was the number of errors
Time frame: Pre-intervention, day 2, 4 and 8 of the intervention
Sleep Duration
Fitbit inspire 3 was used to measure sleep duration (hours:minutes:seconds)
Time frame: 1 week prior to racing and during the race
Sleep: REM
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The Fitbit Inspire 3 was used to measure the total duration of rapid eye motion (REM)sleep during each night for the duration of the study. The REM sleep phase will be analysed in minutes
Time frame: 1 week prior to racing and during the race
Sleep: Non-REM
The Fitbit Inspire 3 will be used to determine the NON-REM sleep phase for each night in minutes
Time frame: 1 week prior to racing and during the race
Sleep: WASO
The FITBIT inspire 3 will be used to measure wake after sleep onset in minutes for each night
Time frame: 1 week prior to racing and during the race
Mechanical efficiency
Mechanical efficiency will be determined during three constant load (100 watts, 150 watts, and 200 watts) cycling bouts of 5 minutes on a calibrated ergometer (Avantronic Cyclus II). Throughout the test, gas exchange will continuously be measured using calibrated metabolic analyzer with a face mask (Cortex, Metalyzer IIIb). VO2 and VCO2 data of the final minute of each workload will be used to calculate gross efficiency (%).
Time frame: pre-intervention and 1 day after the intervention
Time trial performance
The participants will perform a 30-minute time trial. The average power output (watts) achieved will be used as the outcome measure.
Time frame: pre-intervention and 1 day after the intervention
Appetite
Appetite will be assessed with a Likert visual analog scale (0-10) using the following four questions: "How hungry do you feel?" "How full do you feel?" "How satisfied do you feel?" "How much do you think you could eat now?"
Time frame: pre-intervention, during the intervention, 1 day after the intervention
Macronutrient intake
Participants will complete a food diary using the Mijnetemeter application on their phone. Total fat, protein and carbohydrate intake will be determined in grams for each day.
Time frame: baseline, during the intervention
Total energy intake
Participants will complete a food diary, using the Mijnetemeter application on their phones. total energy intake (kilojoules) will be calculated for each day.
Time frame: baseline, during the intervention
Racing intensity
hear rate zones during racing
Time frame: during each stage
Body weight change
Body mass was measured using a SECA, model 813 electrical scale, before and after each stage as a secondary method to assess hydration status. Body mass was measured to the nearest 0.1 kilogram
Time frame: During the intervention