Blood Hormones, Ketone Body, Ketosis, Resistance Exercise, Testing Effect of Intervention
Conditions
Keywords
Ketone bodies, Exogenous ketone supplements, Resistance exercise, Testosterone, Anabolic hormones, Ketone monoester
Brief summary
This study investigates how orally ingested exogenous ketone monoester supplements affect circulating hormone concentrations in healthy young adult males after a single session of resistance exercise. Resistance exercise is known to stimulate an acute increase in the circulating concentration of various hormones that are involved in the regulation of muscle mass, including testosterone, growth hormone (GH), and insulin-like growth factor-1 (IGF-1). Recently, there has been growing interest in how nutritional supplements impact these natural hormone responses at rest. One such intervention is the oral ingestion of exogenous ketone body supplements. Ketone bodies (i.e., β-hydroxybutyrate (β-HB), acetoacetate (AcAc), and acetone) are naturally occurring compounds that are normally produced by the body during prolonged fasting/starvation, or in response to a ketogenic diet (a diet very high in fat and very low in carbohydrates). These ketone body supplements taken in the form of a ketone monoester can quickly raise blood ketone levels without needing to change your diet. Recent research has shown that the ingestion of exogenous ketone supplements or following a 'ketogenic diet' can alter the concentration of certain hormones measured in blood samples at rest. However, the effects of ketone monoester intake on the exercise-induced elevation in circulating hormones is yet to be explored. Therefore, the purpose of this study is to examine how elevated β-HB, induced via the ingestion of the ketone monoester (R)-3-hydroxybutyl-(R)-3-hydroxybutyrate, affects blood concentrations of various anabolic hormones, during post-exercise recovery in healthy young adult males, compared to a placebo drink (flavoured water).
Detailed description
A within-subject crossover design will be used for this randomized, double-blind, placebo-controlled study in healthy males to investigate the impact of ketone monoester (KET) intake on circulating (blood) concentrations of 'anabolic' and other hormones. There are two treatment arms in this crossover trial, including one KET arm and one placebo group. A total of 12 participants will be enrolled and undergo both treatment phases with a minimum 7-day washout period between lab visits. The study will include a screening visit (Visit 1), 10-repetition maximum (10-RM) testing (visit 2), where participants' 10-RM will be determined for each exercise machine used, experimental trial (visit 3), minimum 7-day washout, followed by the phase 2 of the experimental trial (visit 4). During the experimental trials, participants will arrive to the laboratory in an overnight fasted state, and the KET or placebo drink will then be administered following basal blood collection. Then, participants will perform a lower-body resistance exercise session consisting of 5 sets of 10 repetitions of leg press and 3 sets of 12 repetitions of leg extension/leg curl supersets at 95% of their determined 10-RM. Following exercise, another dose of the nutritional treatment will be administered. Arterialized blood samples will then be collected at 13 postprandial timepoints during the 1-hour rested period and the 4-hour post-exercise recovery period to measure changes in plasma glucose and insulin concentration. Arterialized blood samples will also be utilized for quantitation of anabolic hormones, including testosterone, IGF-1, GH, cortisol, luteinizing hormone, sex-hormone binding globulin, dehydroepiandrosterone, estrogen, progesterone, and follicle-stimulating hormone. Additionally, changes in capillary blood β-HB concentration will be assessed throughout the trials by collecting capillary blood samples at baseline and 11 postprandial timepoints during the 1-hour rested period and the 4-hour post-exercise recovery period.
Interventions
DIETARY_SUPPLEMENTKetone Monoester (KET)
Ketone monoester supplement (R)-3-hydroxybutyl (R)-3-hydroxybutyrate based on participants' body weight (0.36g/kg body weight). The ketone brand name: delta G Oxford Ketone Ester.
DIETARY_SUPPLEMENTFlavour matched placebo drink (CON)
\- Flavoured water (non-caloric bitter + citrus flavours)
OTHERResistance Exercise
\- 5 sets of 10 repetitions of leg press and 3 sets of 12 repetitions of leg extension/leg curl 'supersets' (1 set of each back to back with no rest in between sets) at 95% of their 10-RM. Between-set rest intervals for the leg exercises will be 60 seconds.
Sponsors
McGill University
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
TRIPLE (Subject, Investigator, Outcomes Assessor)
Masking description
Participants, Investigators and Outcome Accessors will be blinded to the intervention and control drinks. The drinks will be flavor matched and provided in an opaque bottle. An individual not involved with the study data collection, analysis and interpretation will be designated as a study blinder and randomizer.
Eligibility
Sex/Gender
MALE
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy adult male participants who are 18-40 years of age (inclusive). * BMI \>18.5 and \<30.0 kg/m2 * Recreationally active (at least of 150 minutes of activity/week). * Has maintained stable use of medication and supplements (which are not limited by the
Exclusion criteria
), stable dietary and lifestyle habits, and stable body weight, for the last 3 months prior to screening and agree to maintain them throughout the study. * Be willing to entirely avoid alcohol consumption 48 hours prior to the test days. * Willing and able to agree to the requirements and restrictions of this study, be willing to give voluntary consent, be able to understand and read the questionnaires, and carry out all study-related procedures.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Area under the curve for testosterone concentration. | Baseline and over 4 hours into the post-exercise recovery period | Serum concentration of testosterone (nmol/l) and corresponding area under the curve (AUC), measured at baseline and over 4 hours into the post-exercise recovery period. |
| Time-course data for testosterone concentration. | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Serum concentration of testosterone (nmol/l) measured at baseline and at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Area under the curve for insulin-like growth factor-1 (IGF-1) concentration | Baseline and 4 hours into the post-exercise recovery period | Serum concentration of IGF-1 (nmol/L) and corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Time-course data for IGF-1 concentration | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration of IGF-1 (nmol/L) measured at baseline and at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for cortisol concentration. | Baseline and over 4 hours into the post-exercise recovery period. | Serum concentration of cortisol (nmol/L) and its corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Time-course data for cortisol concentration. | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration of cortisol (nmol/L) measured at baseline and at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for luteinizing hormone concentration | Baseline and 4 hours into the post-exercise recovery period | Serum concentration of luteinizing hormone concentrations (IU/L) and corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Time-course data for luteinizing hormone concentration | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration of luteinizing hormone concentrations (IU/L) measured at13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for dehydroepiandrosterone (DHEA) concentration | Baseline and 4 hours into the post-exercise recovery period. | Serum concentration of DHEA (μmol/L) and corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Time-course data for DHEA concentration | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration of DHEA (μmol/L) measured at baseline and at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for sex hormone-binding globulin (SHBG) concentration | Baseline and over 4 hours into the post-exercise recovery period. | Serum concentration of SHBG (nmol/L) and corresponding area under the curve (AUC), measured at baseline and during the post-exercise recovery period. |
| Time-course data for SHBG concentration. | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration of SHBG (nmol/L) measured at baseline and at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for progesterone concentration | Baseline and over 4 hours into the post-exercise recovery period. | Serum concentration of progesterone (nmol/L) and its corresponding area under the curve (AUC), measured at baseline and during the post-exercise recovery period. |
| Area under the curve for growth hormone concentration | Baseline and over 4 hours into the post-exercise recovery period | Serum concentration of growth hormone (μmol/L) and corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Area under the curve for estrogen concentration | Baseline and over 4 hours into the post-exercise recovery period. | Serum estrogen concentration (pmol/mL) and corresponding area under the curve (AUC), measured at baseline and during the post-exercise recovery period. |
| Time-course data for estrogen concentration | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration for estrogen (pmol/mL) measured at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for follicle stimulating hormone (FSH) concentration | Baseline and over 4 hours into the post-exercise recovery period. | Serum concentration of FSH (IU/l) and corresponding area under the curve (AUC), measured at baseline and during the post-exercise recovery period. |
| Time-course data for FSH concentration. | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration for FSH (IU/l) measured at baseline and at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for glucose concentration | Baseline and 4 hours into the post-exercise recovery period | Plasma glucose concentration (mmol/L) and its corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Time-course data for glucose concentration | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in plasma glucose concentration (mmol/L) measured at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for insulin concentration | Baseline and 4 hours into the post-exercise recovery period | Plasma concentration of insulin (pmol/L) and corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Time-course data for insulin concentration | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in plasma concentration of insulin (pmol/L) measured at baseline and at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Area under the curve for β-HB concentrations | Baseline and 4 hours into the post-exercise and postprandial period | Capillary blood β-OHB concentration (mmol/L) and corresponding area under the curve (AUC), measured at baseline and over the post-exercise recovery period. |
| Time-course data for β-HB concentrations | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in capillary blood β-HB concentrations (mmol/L) measured at 12 timepoints (t = -60, -45, -30, 0, 15, 30, 60, 90, 120, 150, 180, 240 min). |
| Time-course data for progesterone concentration. | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration of progesterone (nmol/L) measured at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
| Time-course data for growth hormone concentration. | Baseline, 1 hour pre-exercise and 4-hours during the post-exercise recovery period. | Changes in serum concentration of growth hormone (μmol/L) measured at 13 timepoints (t = -60, -45, -30, 0, 15, 30, 45, 60, 90, 120, 150, 180, 240 min). |
Countries
Canada
Outcome results
None listed