Altitude Hypoxia, Ketogenic Dieting, Physical Activity
Conditions
Brief summary
A ketogenic diet (KD) reduces daily carbohydrates (CHOs) ingestion by replacing most calories with fat. KD is of increasing interest among athletes because it may increase their maximal oxygen uptake (VO2max), the principal performance limitation at high altitudes. The investigators examined the tolerance of a 4-week isocaloric KD (ICKD) under simulated hypoxia and the possibility of evaluating ICKD performance benefits with a maximal graded exercise bike test under hypoxia and collected data on the effect of the diet on performance markers and arterial blood gases.
Detailed description
In a randomised single-blind cross-over model, 6 recreational mountaineers (age 24 to 44 years) will complete a 4-week ICKD followed or preceded by a 4-week habitual mixed western diet (HD). Performance parameters (VO2max, lactate threshold \[LT\], peak power \[Ppeak\]) and arterial blood gases (PaO2, PaCO2, pH, HCO3-) will be measured at baseline under two conditions (normoxia and hypoxia) as well as after a 4-week HD and 4-week ICKD under the hypoxic condition.
Interventions
DIETARY_SUPPLEMENTIsocaloric ketogenic diet
The ICKD definition was based on the works of Sansone (2018) and Trimboli (2020). We defined ICKD as a daily CHOs ingestion \< 30 to 50 g.d-1, without any limitation in fat consumption. Participants self-selected their own diet based on a list of advised and forbidden foods developed to fit the definition of ICKD. There were no instructions to limit calories.
Sponsors
Clinique Romande de Readaptation
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
20 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Recreational mountaineers * Familiarity with altitude (\>2500 m above sea level) and males/females 20 to 45 years old.
Exclusion criteria
* high training load (such as professional athletes) or new planned training * dietary restrictions.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Performance test under hypoxic conditions | after 4 weeks of diet | VO2max cycling test on ergometer |
Countries
Switzerland
Outcome results
None listed