Influence of the Time of Day in the Effect of Caffeine on Maximal Fat Oxidation During Exercise in Women (CIRCAF_WOM)

Universidad Francisco de Vitoria

Status: Completed

Conditions: Dietary Supplement

Treatments: Dietary Supplement: Acute caffeine supplementation

Study type: Interventional

Funder types: Other

Identifiers

NCT05880186

UFVitoria_2

Details and patient eligibility

About

Caffeine is a natural stimulant with well-recognized metabolic benefits, however, there is a lack of studies investigating the time-of-day caffeine influence to enhance fat oxidation in women. The aim of this study was to evaluate the influence of the time of the day on the effect of caffeine on maximal rate of fat oxidation during aerobic exercise in women.

Full description

Caffeine is a natural stimulant with well-recognized sports performance benefits. Aside its performance-enhancing effect, caffeine has the potential of increasing fat utilization during aerobic exercise at submaximal intensities, lowering-down the contribution of carbohydrate as a fuel. This property of caffeine may provoke a glycogen-sparing effect in the skeletal muscle and liver for exercise situations where carbohydrate availability may be a challenge. Additionally, the capacity of caffeine to enhance fat utilization during exercise could be of interest for improving health outcomes as it may increase the rate of change in body composition in exercise programs. Maximal fat oxidation rate (MFO) during exercise is a remarkable physiological indicator associated with metabolic flexibility/body weight loss and endurance performance To date, it is unknown if caffeine increases MFO in the same proportion during morning and evening exercise trials in women. For this reason, the aim of the present study was to evaluate the influence of the time of the day on the effect of caffeine on MFO in women. We hypothesised that caffeine would increase MFO during morning and evening exercise and this effect would be of similar magnitude at both times of day.

Enrollment: 14 patients

Sex: Female

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• To be non-smokers.
• To have low caffeine intake (i.e., < 50 mg of caffeine per day in the previous 2 months)
• To show no previous history of cardiopulmonary diseases or having suffered musculoskeletal injuries in the previous 6 months.
• To have a regular duration of their menstrual cycle for the previous 6 months.
• To confirm no existence of any type of menstrual disorders such as dysmenorrhea, amenorrhea, or strong symptoms associated with pre-menstrual syndrome.

Exclusion criteria

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Quadruple Blind

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14 participants in 2 patient groups, including a placebo group

Caffeine intake

Experimental group

Description:

Test in the morning A dose of 3 mg/kg of caffeine (Bulk Powders, Essex, United Kingdom) was ingested before the beginning of each test. Test in the evening A dose of 3 mg/kg of caffeine (Bulk Powders, Essex, United Kingdom) was ingested before the beginning of each test.

Treatment:

Dietary Supplement: Acute caffeine supplementation

Placebo intake

Placebo Comparator group

Description:

Test in the morning A dose of 3 mg/kg of placebo (Cellulose, Guinama, Valencia, Spain) was ingested before the beginning of each test. Test in the evening A dose of 3 mg/kg of placebo (Cellulose, Guinama, Valencia, Spain) was ingested before the beginning of each test

Treatment:

Dietary Supplement: Acute caffeine supplementation