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NCT Number: NCT06683547

The Impact of Ketone Monoester Intake on Post-exercise Hormonal Responses After Resistance Exercise in Young Males

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).

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Key information

Conditions

Ketosis Acid-Base Imbalance Acidosis Blood Hormones Ketone Body Metabolic Diseases Nutritional and Metabolic Diseases Resistance Exercise Testing Effect of Intervention

Age range

18 year–40 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

McGill University

Montreal, Quebec, H2W 1S4, Canada

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Exclusion criteria

  • Individuals with metabolic disorders including: Type I or Type II diabetes.
  • Individuals with a history of thrombosis / cardiovascular disease, endocrine disorders
  • Individuals with knee injuries (i.e., ACL injuries).
  • Individuals with a positive medical history of unstable thyroid disease (i.e., hypothyroidism, hyperthyroidism, hyperparathyroidism, and hypoparathyroidism) and immune disorders.
  • Individuals who have used tobacco products within the last 6 months.
  • Chronic usage of medications known to modulate hormone levels (i.e. corticosteroids and hormone replacement therapy (HRT)) in the last 6 months.
  • Current use of ketone supplements or adherence to a ketogenic diet.
  • Formal or regular weightlifting activity within the last year.

Treatment and study plan

Ketone Monoester (KET)

Dietary Supplement

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.

Flavour matched placebo drink (CON)

Dietary Supplement
  • Flavoured water (non-caloric bitter + citrus flavours)

Resistance Exercise

Other
  • 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.

Primary outcomes

  1. Area under the curve for testosterone concentration.

    Time frame: 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.

  2. Time-course data for testosterone concentration.

    Time frame: 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 outcomes

  1. Area under the curve for growth hormone concentration

    Time frame: 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.

  2. Time-course data for growth hormone concentration.

    Time frame: 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).

  3. Area under the curve for insulin-like growth factor-1 (IGF-1) concentration

    Time frame: 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.

  4. Time-course data for IGF-1 concentration

    Time frame: 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).

  5. Area under the curve for cortisol concentration.

    Time frame: 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.

  6. Time-course data for cortisol concentration.

    Time frame: 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).

  7. Area under the curve for luteinizing hormone concentration

    Time frame: 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.

  8. Time-course data for luteinizing hormone concentration

    Time frame: 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).

  9. Area under the curve for dehydroepiandrosterone (DHEA) concentration

    Time frame: 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.

  10. Time-course data for DHEA concentration

    Time frame: 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).

  11. Area under the curve for sex hormone-binding globulin (SHBG) concentration

    Time frame: 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.

  12. Time-course data for SHBG concentration.

    Time frame: 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).

  13. Area under the curve for progesterone concentration

    Time frame: 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.

  14. Time-course data for progesterone concentration.

    Time frame: 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).

  15. Area under the curve for estrogen concentration

    Time frame: 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.

  16. Time-course data for estrogen concentration

    Time frame: 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).

  17. Area under the curve for follicle stimulating hormone (FSH) concentration

    Time frame: 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.

  18. Time-course data for FSH concentration.

    Time frame: 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).

  19. Area under the curve for glucose concentration

    Time frame: 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.

  20. Time-course data for glucose concentration

    Time frame: 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).

  21. Area under the curve for insulin concentration

    Time frame: 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.

  22. Time-course data for insulin concentration

    Time frame: 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).

  23. Area under the curve for β-HB concentrations

    Time frame: 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.

  24. Time-course data for β-HB concentrations

    Time frame: 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).

Sponsors and collaborators

Lead sponsor

McGill University

Other

Registry information

Official study title

The Impact of Ketone Monoester Intake on Post-exercise Hormonal Response During Recovery Following an Acute Bout of Resistance Exercise.

Important dates

Study start
2025
Primary completion
2025
Study completion
2025
First posted
Nov 12, 2024
Registry last updated
Sep 2, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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