A Phase 2/3 interventional study of HMB supplementation and Placebo treatment in Supplementation, Sport and Sports Nutrition, sponsored by Poznan University of Physical Education. Completed at 2 sites in 2 countries. Open to male participants aged 20 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-10-02.
Sponsored by Poznan University of Physical Education · Phase 2/3, Interventional, and Treatment
The study aims at assessing the influence of β-hydroxy-β-methylbutyrate (HMB) free acid supplementation (90 mg/kg of fat free body mass/day) supplemented for 21 days on protein kinases activity and selected hormones levels, and subsequent improvements in muscle protein synthesis, lean body mass content and aerobic capacity.
The main aim of the project is to assess the effects of 21 days of HMB (90 mg/kg of fat free body mass per day) or Placebo (PLA) supplementation under two distinct exercise/stress stimulus conditions in the groups of exercise trained participants (S group) and individuals showing features of malnutrition (W group) on the activity of Akt/PBK/mTOR/p70S6K and MAPK/ERK protein kinase pathway in peripheral blood mononuclear cells and muscle; blood concentrations of free and total testosterone, cortisol, IGF-1 and growth hormone; level of resting and exercise energy metabolism rate and alternations in energy sources utilization during exercise, as well as aerobic capacity and body composition.
The study is a double-blind, randomized, placebo-controlled, parallel-group trial. The study protocol consists of two 21-days supplementation periods. Within the first period of the trial the participants will follow their customary physical exercise (S group) / lifestyle (W group). In turn, in the second period of the trial the routine training (S group) or customary lifestyle (W group) will be supplemented twice a week with a functional training program, as a source of an additional exercise/stress stimulus.
Investigators aim to recruit 60 exercise trained individuals (S group) and 60 will be inactive individuals showing features of malnutrition (W group). Random allocation of participants to the HMB and PLA treatments will be done using a random sequence generator, with groups being equalised by fat-free mass level (within S group and W group separately).
At the first preliminary visit anthropometric measurements, and familiarization with exercise test procedures [i.e., incremental cycling test with ergorespirometry, maximal voluntary isometric contraction test (MVIC; performed in a Biodex isokinetic dynamometer)] will be performed. After the completion of the preliminary tests, the participants within S group and W group will be divided randomly into two treatments: 90mg/kgFFM per day of HMB or the same amount of PLA. There will be two 21-days supplementation periods differing in the type of exercise/stress stimulus of the organism.
Before the start of supplementation period (T1) and after their completion (T2 and T3) the series of testing procedures will be performed, each of the series will consist of one day. Each testing series (T1, T2, and T3) will include anthropometric measurements followed by pre-exercise (pre-Ex) blood collection (for the determination of the activity of signaling protein kinases in peripheral blood mononuclear cells; hormone concentrations: free and total testosterone, cortisol, IGF-1 and growth hormone; concentrations of alternative energy sources: ketone bodies \<acetoacetate and beta-hydroxybutyrate> and free fatty acids; activity of selected enzymes: lactate dehydrogenase \<LDH>, and creatine kinase \<CK>; gasometric indices: pH, pCO2, pO2 and electrolytes: Ca2+, Na+, K+, Cl-; concentrations of other biochemical indices: myoglobin, urea, creatinine, glucose, lactate, bilirubins ), the m. vastus lateralis ultrasound and collection of the m. vastus lateralis samples using the percutaneous muscle microbiopsy technique (for the determination of the activity of signaling protein kinases). After the resting pre-Ex procedures, the ICT will be performed. Then the post-exercise (post-Ex) blood sampling and second muscle microbiopsy will be carried out. Finally, at the end of the procedures the MVIC will be assessed.
After collection all the data, comparisons between supplementation treatment conditions (HMB vs PLA) within groups and supplementation periods, as well as comparisons between studied groups (S group vs W group) within supplementation treatment and supplementation period will be performed using T-test for independent variables. Comparisons between supplementation periods within studied groups and supplementation treatment will be performed via T-test for dependent variables. Statistical analysis will be performed using Statistica v. 13.3, StatSoft Polska Sp. z o.o., 2022.
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The experimental procedure for each participant in this group includes a two 21-days periods HMB supplementation. HMB will be administered in the form of blinded liquid containing 1 mL HMB free acid per 30 drops. The liquid HMB will be ingested with at least 100 mL of water. Each participant will ingest individualized dose of 90 mg HMB/kgFFM/day of liquid HMB free acid in a split dose per day. On training days in the S group during the first and the second period of supplementation and on training days in W group during the second period of supplementation the supplement will be taken before (half of the individual daily dose) and immediately after training session (second half of the individual daily dose), On rest days the supplements will be taken in the morning (half of the individual daily dose) and before bedtime (second half of the individual daily dose).
Dietary Supplement: HMB supplementation
The experimental procedure for each participant in this group includes a two 21-days periods Placebo supplementation. PLA (liquid placebo similar in appearance, taste and smell to HMB, but containing no HMB) will be placed in the blinded liquid form. PLA will be ingested with at least 100 mL of water. Each participant will ingest individualized dose of 90 mg PLA/kgFFM/day of liquid PLA in a split dose per day. On training days in the S group during the first and the second period of supplementation and on training days in W group during the second period of supplementation, the PLA will be taken before (half of the individual daily dose) and immediately after training session (second half of the individual daily dose), On rest days the PLA will be taken in the morning (half of the individual daily dose) and before bedtime (second half of the individual daily dose).
Dietary Supplement: Placebo treatment
Group taking oral HMB free acid supplementation in a blinded liquid form.
Group taking oral supplementation with placebo (in a blinded liquid form).
Change in the molecular potential after supplementation and exercises-induced stress stimuli on the organism
AKTser473, mTORSer2448, p70S7K1Thr389, 4E-BP1Ser65/Thr70, and 4EBP1Thr37/46 kinase activity (optical density)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in the muscle cholesterol and mevalonate content (in the vastus lateralis muscle samples) after supplementation and exercises-induced stress stimuli on the organism
Muscle cholesterol and mevalonate content (units)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in blood concentrations of hormones: free and total testosterone, cortisol, IGF-1, growth hormone after supplementation and exercises-induced stress stimuli on the organism.
Blood free and total testosterone, cortisol, IGF-1, growth hormone content
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in creatine kinase (CK) and lactate dehydrogenase (LDH) activity (IU) in blood after supplementation and exercises-induced stress stimuli on the organism
CK and LDH activity (IU)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in body mass and body mass composition after supplementation and exercises-induced stress stimuli on the organism
Body mass, fat free mass, fat mass (kg)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in maximal oxygen uptake during the incremental cycling test after supplementation and exercises-induced stress stimuli on the organism
VO2max level (mL/min)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in total body water content after supplementation and exercises-induced stress stimuli on the organism
Body water content (L)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in other biochemical indices: myoglobin, urea, creatinine, glucose, lactate, bilirubins and electrolytes (Ca2+, Na+, K+, Cl-) after supplementation and exercises-induced stress stimuli on the organism
Blood concentrations of : myoglobin (mmol/L), urea (mmol/L), creatinine (mmol/L), glucose (mmol/L), lactate (mmol/L), bilirubins (mmol/L), and electrolytes \[Ca2+, Na+, K+, Cl-\] (mmol/L)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in utilization of energy substrates during rest and physical exercise after supplementation and exercises-induced stress stimuli on the organism
Utilization of energy substrates - fats, carbohydrate and protein during rest and exercise (g/min)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in resting and exercise energy expenditures after supplementation and exercises-induced stress stimuli on the organism
Energy expenditure during rest and exercise (kcal/min)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in total daily energy expenditures after supplementation and exercises-induced stress stimuli on the organism
Daily energy expenditure (kcal/day)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in specific exercise performance test Fight Gone Bad after supplementation and exercises-induced stress stimuli on the organism
Number of repetitions of five different exercise - sumo deadlift high-pulls, wall ball shots, box jumps, push press and rowing on an ergometer in each of three exercise rounds and total number of repetitions of all exercises of all exercise rounds (reps
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
Changes in the maximum voluntary isometric contraction (MVIC) after supplementation and exercises-induced muscle damage
Maximum voluntary isometric contraction (MVIC) torque (Nm)
Time frame: Day 0 [Baseline (before treatment)] and after 21 days of each two supplementation periods
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Poznan University of Physical Education