ANZCTR - Registration

Please note the ANZCTR will be unattended from Friday 20 December 2024 for the holidays. The Registry will re-open on Tuesday 7 January 2025. Submissions and updates will not be processed during that time.

Registering a new trial?

To achieve prospective registration, we recommend submitting your trial for registration at the same time as ethics submission.

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers

Trial registered on ANZCTR

Registration number

ACTRN12623000184673

Ethics application status

Approved

Date submitted

17/01/2023

Date registered

21/02/2023

Date last updated

21/02/2023

Date data sharing statement initially provided

21/02/2023

Type of registration

Prospectively registered

Titles & IDs

Public title

Effects of ketone supplementation on recovery from endurance exercise in recreationally active males

Scientific title

Effects of ketone supplementation on rates of muscle protein synthesis following leg cycling in recreational active males

Secondary ID [1]

None

Universal Trial Number (UTN)

Trial acronym

KAPER (Ketones and Post-Exercise Recovery)

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Skeletal muscle recovery

Condition category

Condition code

Musculoskeletal

Normal musculoskeletal and cartilage development and function

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

10 well-trained male cyclists/triathletes (A-B grade, training >200km/week, 18-35 years old, BMI 18.5 – 24.9 kg/m^2) will be included in this randomised, double-blind placebo-controlled cross-over study. Prior to the first training session, all participants will complete preliminary testing including a 3-day food record, body composition scan (DXA), fitness testing (VO2peak test) and exercise session familiarisation.

During the experimental visits, a total of 3 muscle biopsies and 10 blood samples (~10 mL / sample) will be obtained from each participant. Participants will complete a total of two experimental exercise sessions with 1-2 weeks of recovery between sessions. The first exercise session of the experimental period will involve random selection for supplementation with either a commercially available ketone ester (KE) or energy-matched placebo (PL), and the second session will involve a single session supplementing with the opposite treatment (i.e., what was not consumed in the first exercise session). Participants will keep a food record and receive dietary instruction from accredited dietitians to meet individual energy targets prior to the two exercise sessions.

On experimental days, participants will report do the lab following an overnight fast. A Teflon catheter will then be inserted into an antecubital (inside of elbow) vein for basal blood collection. A second catheter will be inserted into a pre-heated vein of the opposite hand for blood collection. Following basal blood collection, the plasma phenylalanine pool will be primed with an intravenous dose of L-[ring-(13)C(6)]-phenylalanine and directly thereafter a continuous tracer infusion will commence and participants will be provided with a low-protein, carbohydrate (CHO) rich breakfast (e.g., ~2.0g/kg body mass (BM) CHO, <0.2g/kg BM protein).

Participants will then complete a supervised leg-cycling exercise protocol consisting of 6x30 min continuous blocks of alternating intensities to mimic a cycling road race. Upon completion of the exercise protocol, a first muscle biopsy will be taken from the vastus lateralis muscle to determine the background enrichment and basal muscle protein synthetic rate. Participants will then be fed a recovery beverage containing carbohydrate and protein consistent with current dietary post-exercise recommendations (3g/kg BM CHO, 25 g protein) well as either a ketone ester (573 mg/kg) or taste-matched placebo (bitter tasting solution containing sucrose octaacetate dissolved in water), with a maintenance dose (286 mg/kg ketone or placebo) consumed every hour (i.e., at 1, 2, 3 and 4 h post exercise) to maintain circulating ketone availability.

To determine post-prandial muscle protein synthesis, another 2 biopsies will be taken at 2 h and 5 h post exercise. Participants will then be provided with a self-serve buffet style dinner where they can self-select from a range of healthy, nutritious foods in accordance with their personal preferences. During this time (~45 min), they will be asked to fill out several surveys related to feelings of hunger, fullness, and GI upset/discomfort. Participants will remain in the lab under supervision for the full duration of the experimental visit.

Intervention code [1]

Treatment: Other

Intervention code [2]

Lifestyle

Comparator / control treatment

Participants will be randomised to treatment (active or placebo), and perform all trials in a cross-over design. The placebo will be a taste matched drink containing a bitter tasting solution (sucrose octaacetate) dissolved in water. Drinks will be provided in identical opaque bottles to prevent visible identification of treatment.

Control group

Placebo

Outcomes

Primary outcome [1]

Rates of skeletal muscle protein synthesis (expressed as fractional synthetic rate (FSR in %/h), as measured by incorporation of L-[ring-(13)C(6)]-phenylalanine tracer in muscle biopsy samples as described previously (Smiles et al. 2019, PMID: 30840513).

Timepoint [1]

Post exercise skeletal muscle FSR will be determined from muscle biopsies taken immediately post exercise (t=o) and 2 (t=120 min) and 5 h (t=300 min) into the recovery period.

Secondary outcome [1]

Composite measures of appetite and satiety (acetylated gherlin, leptin, PYY, PP, Amylin) will be measured in venous blood samples via commercially available ELISA and/or automated blood analyser

Timepoint [1]

Appetite and satiety markers will be measured from blood samples collected:
-fasted (prior to consumption of standardised breakfast)
- 1 h and 2 h post prandial prior to start of exercise
- immediately post exercise (t=0)
- t=60min, t=120 min, t=300min post exercise

Secondary outcome [2]

Perceived satiety will be measured in individuals using a standardised visual analogue scale (VAS; 100mm)

Timepoint [2]

VAS for satiety markers will be collected:
-fasted (prior to consumption of standardised breakfast)
- 2 h post prandial prior to start of exercise
- immediately post exercise (t=0)
- t=120 min, t=300min post exercise

Secondary outcome [3]

Measures of gastrointestinal (GI) discomfort will be measured using a 10-point rating modified scale to determine upper and lower gastrointestinal symptoms as well as composite overall gut discomfort.

Timepoint [3]

GI discomfort will be measured
-fasted (prior to consumption of standardised breakfast)
- 2 h post prandial prior to start of exercise
- immediately post exercise (t=0)
- t=120 min, t=300min post exercise

Secondary outcome [4]

Composite measures of inflammation and iron metabolism (ferritin, hepcidin, IL-6) be measured in venous blood samples via commercially available ELISA and/or automated blood analyser as previously described (McKay et al. 2022, PMID: 34690285)

Timepoint [4]

Inflammation and iron metabolism markers will be measured from blood samples collected:
-fasted (prior to consumption of standardised breakfast)
- 2 h post prandial prior to start of exercise
- immediately post exercise (t=0)
- t=60min, t=180, t=300 min post exercise

Secondary outcome [5]

Composite measures of bone metabolism (CTX, P1NP, OC) measured in blood serum via an automated blood analyser as previously described (Fensham et al 2022, PMID: 35869933)

Timepoint [5]

Bone markers will be measured from blood samples collected:
-fasted (prior to consumption of standardised breakfast)
- 2 h post prandial prior to start of exercise
- immediately post exercise (t=0)
- t=60min , t=120min, t=180 post exercise

Secondary outcome [6]

Plasma ketone (beta-hydroxybutyrate) concentrations via commercially available colorimetric kits

Timepoint [6]

Ketone concentrations will be assessed
-fasted (prior to consumption of standardised breakfast)
- 2 h post prandial prior to start of exercise
- immediately post exercise (t=0)
- t=60min , t=120min, t=180, t=300 post exercise

Secondary outcome [7]

Plasma enrichments of L-[ring-13C6]-phenylalanine via gas chromatography-mass spectrometry (GC-MS)

Timepoint [7]

Plasma will be collected
-fasted (prior to consumption of standardised breakfast)
-2 h post prandial prior to the start of exercise
-immediately post exercise (t=0)
-t=30, t=60, t-90, t=120, t=180, t=240, t=300 min post exercise

Secondary outcome [8]

Perceived appetite will be measured in individuals using a standardised visual analogue scale (VAS; 100mm)

Timepoint [8]

VAS for appetite will be collected:
-fasted (prior to consumption of standardised breakfast)
- 2 h post prandial prior to start of exercise
- immediately post exercise (t=0)
- t=120 min, t=300min post exercise

Eligibility

Key inclusion criteria

Participants will be recruited if they meet the following criteria:
• Male
• Aged 18-35 y
• BMI: 18.5-24.9 kg/m2
• Recreationally active (A-B grade cyclists or triathletes currently cycling ~200km/week) capable of completing the 180 min intermittent intensity exercise protocol
• No cardiopulmonary abnormalities
• No injuries
• Pass the ESSA pre-exercise screening tool and/or obtain GP clearance to exercise

Minimum age

18 Years

Maximum age

35 Years

Sex

Males

Can healthy volunteers participate?

Yes

Key exclusion criteria

Exclusion criteria:
• Known cardiovascular disease or diabetes mellitus
• Known bleeding disorder (i.e. hemophilia A [factor VIII deficiency]
• Hemophilia B [factor IX deficiency]
• von Willebrand disease, or other rare factor deficiencies including I, II, V, VII, X, XI, XII and XIII)
• Major or chronic illness that impairs mobility or eating/digestion
• Taking prescription medications (i.e. beta-blockers, anti-arrhythmic drugs, statins, insulin sensitising drugs, or drugs that increase the risk of bleeding [i.e. anticoagulants, antiplatelets, novel oral anticoagulants [NOAs], nonsteroidal anti-inflammatory drugs [NSAIDs], selective norepinephrine reuptake inhibitors [SNRI], or selective serotonin reuptake inhibitors [SSRIs]
• Unable or unwilling to have a muscle biopsy
• Weight has changed more than 5kg in past 3 months
• Currently on a restrictive diet
• Unable to attend the lab in Fitzroy, Melbourne for the 4 study visits for completion of study protocol

Study design

Purpose of the study

Treatment

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

Sealed opaque envelopes.

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Simple randomisation using computer-generated, randomised sequence. An independent third party will prepare the computer-generated randomisation lists and sealed envelopes for randomisation.

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

The people receiving the treatment/s
The people administering the treatment/s

Intervention assignment

Crossover

Other design features

Phase

Not Applicable

Type of endpoint/s

Efficacy

Statistical methods / analysis

Statistical analysis: Data obtained will be analysed using Generalised Linear Mixed Models. Statistics will analyse factor (time: baseline, 2 h and/or 5 h post-exercise) and treatment (ketone vs. placebo). Statistical significance will be set at P<0.05. A power calculation was performed with differences in postprandial MPS as the primary outcome measure. Based on published data (Koopman R et al. Nutr. 2009 PMID: 19625697), we estimate the standard deviation for MPS to be ~0.0065 %/h. We estimate that to determine an ~20% difference between treatments at an a level of 0.05 and power (1 - ß) of 0.8, we will need to recruit 7 subjects. This is considered clinically relevant difference between interventions. Therefore, to account for possible dropouts, we will recruit a total of 10 subjects to participate in the study.

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

28/02/2023

Actual

Date of last participant enrolment

Anticipated

4/09/2023

Actual

Date of last data collection

Anticipated

2/10/2023

Actual

Sample size

Target

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

VIC

Funding & Sponsors

Funding source category [1]

University

Name [1]

Australian Catholic University

Address [1]

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Resarch
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country [1]

Australia

Primary sponsor type

Individual

Name

Dr Jamie Whitfield

Address

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Resarch
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country

Australia

Secondary sponsor category [1]

Individual

Name [1]

Dr. Alannah McKay

Address [1]

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Research
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country [1]

Australia

Secondary sponsor category [2]

Individual

Name [2]

Professor Louise Burke

Address [2]

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Research
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country [2]

Australia

Secondary sponsor category [3]

Individual

Name [3]

Professor John Hawley

Address [3]

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Research
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country [3]

Australia

Secondary sponsor category [4]

Individual

Name [4]

Professor Luc van Loon

Address [4]

Department of Human Biology NUTRIM School of Nutrition and Translational Research in Metabolism,
Maastricht University Medical Centre,
P.O. Box 616, 6200 MD,
Maastricht

Country [4]

Netherlands

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Australian Catholic University Human Research Ethics Committee (ACU HREC)

Ethics committee address [1]

Manager, Ethics 
c/o Office of the Deputy Vice Chancellor (Research)
Australian Catholic University
North Sydney Campus
PO Box 968
North Sydney, NSW 2059

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

15/03/2022

Approval date [1]

29/06/2022

Ethics approval number [1]

2022-2580H

Summary

Brief summary

Athletes across many disciplines engage in structured, periodized training plans to promote adaptation and ultimately optimise performance. However, recent research has made it clear that manipulating the provision of nutritional support throughout training and during the recovery periods can play an equally important a role in determining performance outcomes. Over the last 20+ years, exercise science research has primarily focused on the provision of carbohydrate and protein to facilitate glycogen replenishment and skeletal muscle repair, respectively. More recently, scientific studies have begun exploring whether supplementing with beverages containing ketone esters may provide an alternative fuel source to support exercise and subsequent recovery. To date, the evidence to support ketone use during exercise is mixed, but there have been promising findings suggesting that this fuel may promote muscle repair, and may reduce the likelihood of athletes developing symptoms of overtraining.  While the finding that exogenous ketones may increase the activity of the machinery response for building new proteins is exciting; it remains to be determined whether supplementing with ketones can increase the rate of muscle protein synthesis (MPS) following exercise. Therefore, the primary aim of this study is to measure the effects of a ketone supplement or energy-matched placebo on MPS following an acute bout of endurance exercise in trained cyclists.

In addition to a proposed enhancement of muscle repair and adaptation, the intake of ketone esters is claimed to act as an appetite suppressant to assist with the aggressive manipulation of physique prized by many road cyclists.  Indeed, despite reports of an increased energy intake and reduction in markers of over-reaching in a ketone-supplemented group following intensified cycling training, there have been observations of suppression of hormones linked to hunger (e.g., ghrelin), self-reported hunger and desire to eat in the hours following the intake of ketone ester supplements in sedentary humans and supportive evidence in rodent models. Other effects associated with post-exercise ketosis achieved via adaptation to a ketogenic diet also merit investigation in relation to the post-exercise supplementation with ketone esters; these include alterations to iron and bone metabolism. Therefore, the secondary aim of this study is to examine the effect of ketone ester supplementation on other effects on post-exercise recover including impacts on hunger and appetite, as well as on markers linked to iron metabolism and bone health.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Dr Jamie Whitfield

Address

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Resarch
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country

Australia

Phone

+61 3 9230 8252

Fax

jamie.whitfield@acu.edu.au

Contact person for public queries

Name

Jamie Whitfield

Address

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Resarch
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country

Australia

Phone

+61 3 9230 8252

Fax

jamie.whitfield@acu.edu.au

Contact person for scientific queries

Name

Jamie Whitfield

Address

Exercise and Nutrition Research Program
Mary MacKillop Institute for Health Resarch
Level 5, 215 Spring Street
Melbourne, VIC 3000

Country

Australia

Phone

+61 3 9230 8252

Fax

jamie.whitfield@acu.edu.au

Data sharing statement

Will individual participant data (IPD) for this trial be available (including data dictionaries)?

No/undecided IPD sharing reason/comment

Potentially identifiable data

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

No additional documents have been identified.

Trial Review

Registering a new trial?

Documents added manually

Documents added automatically