Beer or Ethanol Effects on the Response to High Intensity Interval Training: A Controlled Study in Healthy Individuals

Aims:

To determine the effect of habitual and moderate consumption of beer on physical fitness, body composition, psychokinetic and cognitive abilities and psychological status in sedentary healthy adults undergoing a HIIT training program.

The primary hypothesis will that a HIIT program will induce an improvement on physical fitness, body composition, psychokinetic abilities and psychological responses compared to a control group but this positive effect could be blunted by alcohol intake.

Methods:

HIIT-BEER will recruit 80 sedentary, healthy, adults (50% women) aged 18-40 years.

Will be performed a 10-week controlled trial in which the effects of HIIT will be compared to a control group without training. The effects of habitual intake of different alcoholic beverage will be also compared.

After completing the baseline measurements, the selected participants will be randomly assigned to either the control or the exercise training groups. The participants included in the training groups will be asked to choose individual choice about their drinking preference for alcoholic or non-alcoholic beverages. The participants who chose alcohol intake will be randomly assigned into the training group with alcohol beer intake (5.4% Alcohol-Special Alhambra®, Cervezas Alhambra, Spain) or to the sparkling water group with exactly the same amount of distilled alcohol added. The distilled alcoholic beverage used for the investigator's study will be vodka because of the purity of its composition (37.5% ethanol and 62.5% water). The participants who chose non-alcoholic beverages will be randomized into the training groups of non-alcohol beer (0.0% alcohol-Cruzcampo®, Heineken España) or sparkling water (Eliges (IFA) Eliqua 2®, Font Salem, Spain) intakes.

So, eligible participants will be assigned to five groups: (i) a group that will performed HIIT and will consumed 330 ml (women) or 2x300 ml (men) of beer with 5.4% alcohol (HIIT-AB, n=16); (ii) a group that will performed HIIT and will consumed the same amount of beer without alcohol (0.0%) (HIIT-NAB; n=16); (iii) a group that will performed HIIT and will consumed the same amount of sparkling water (0.0%) (HIIT-W; n=16); (iv) a group that will performed HIIT and will consumed sparkling water with the same amount of alcohol than the pre-established beer (5.4%) (HIIT-ASW; n=16); and (v) a control group that will not perform any physical training program (CON; n=16).

The beverage intakes will be programmed from Monday to Friday. There will not specific recommendation for Saturday and Sunday, but the participants will be instructed to keep a moderate alcohol during the weekend.

Laboratory measures completed at baseline and 10 weeks later, include physical fitness (cardiorespiratory fitness, muscular strength), body composition, hearth rate variability (HRV), reaction time, cognitive variables and health-related questionnaires. The investigators will also obtain dietary habits data and cardiovascular disease risk factors.

Inclusion criteria

• Age: 18-40 years
• BMI:18.5-25 kg/m2
• Not engaged in regular physical activity >20min on >3days/week
• Not participating in a weight loss programme
• Stable weight over the last 5 months (body weight changes>5kg)
• Participant must be capable and willing to provide consent, understand exclusion criteria and accept the randomized group assignment
• Normal electrocardiogram
• Not personal family history related to alcohol consumption.

Exclusion criteria

• History of cardiovascular disease
• Diabetes
• Pregnancy or planning to get pregnant during study period
• Beta blockers or benzodiapezins use
• Taking medication for thyroid
• Other significant conditions that are life-threatening or that can interfere with or be aggravated by exercise
• Unwillingness to either complete the study requirements or to be randomized into control or training group