Influence of daily beer or ethanol consumption on physical fitness in response to a high-intensity interval training program. The BEER-HIIT study

Abstract

Background: High-intensity interval training (HIIT) is an effective approach to improve physical fitness, but consuming beer, which is a regular practice in many physically active individuals, may interfere with these effects. The purposes of this study were to investigate the effects of a 10-week (2 days/week) HIIT program on cardiorespiratory fitness, muscle strength and power parameters, and also to assess the possible influence on them of a moderate consumption of beer (at least from Monday to Friday) or its alcohol equivalent.

Methods: Young (24 ± 6 years old) healthy adults (n = 73, 35 females) were allocated to five groups. Four groups participated in the HIIT intervention program while the fifth group was a control Non-Training group (n = 15). Participants in the training groups chose whether they preferred receiving alcohol or alcohol-free beverages. Those choosing alcohol were randomized to either beer or ethanol intake: (i) T-Beer group (alcohol beer, 5.4%; n = 13) or (ii) T-Ethanol (sparkling water with vodka, 5.4%; n = 14). Those choosing alcohol-free intake were randomized to (iii) T-Water group (sparkling water, 0.0%; n = 16), or (iv) T-0.0Beer group (alcohol-free beer, 0.0%; n = 15). Men ingested 330 ml of the beverage at lunch and 330 ml at dinner; women ingested 330 ml at dinner. Before and after the intervention, maximal oxygen uptake in absolute and relative terms (VO2max.), maximal heart rate, total test duration, hand grip strength and four types of vertical jumps were measured.

Results: HIIT induced significant improvements in absolute and relative values of VO2max, and total test duration (all p < 0.05) in all the training groups; also, clinical improvements were found in hand grip strength. These positive effects were not influenced by the regular intake of beer or alcohol. No changes in the vertical jumps occurred in any of the groups.

Conclusions: A moderate beer or alcohol intake does not mitigate the positive effect of a 10-week HIIT on physical fitness in young healthy adults.

Trial registration: ClinicalTrials.gov ID: NCT03660579. Registered 20 September 2018. Retrospectively registered.

Keywords: Alcohol; Exercise; Fitness; Strength; VO2max.

Conflict of interest statement

The authors have no conflicts of interest that are directly relevant to the content of this article. Manuel J. Castillo is a former member of the Scientific Advisory Board of the CICS. The funders had no role in the design of the study, in the collection, analyses, or interpretation of data, in the writing of the manuscript, or in the decision to publish the results.

Figures

Fig. 1

Flow-chart diagram

Fig. 2

Changes in maximum oxygen uptake (VO2max.) in absolute (a) and relative terms (b), maximal heart rate (c), and total test duration (d) before and after the intervention study. P-value [time, group, and interaction (time x group)] of repeated measure analysis of variance. ** p < 0.01, *** p < 0.001 for total sample, ö p < 0.05, öö p < 0.01, ööö, p < 0.001 for women, å p < 0.05, åå p < 0.01, ååå p < 0.001 for men, obtained by Student’s paired t-test. Data are shown as means. Abbreviations: T-Beer, group that performed HIIT and consumed alcohol beer; T-0.0Beer, the group that performed HIIT and consumed non-alcoholic beer; T-Water, the group that performed HIIT and consumed sparkling water; T-Ethanol, the group that performed HIIT and consumed sparkling water with added alcohol

Fig. 3

Changes in total hand grip (a), squat jump (b), counter-movement jump (c), Abalakov jump (d), and drop jump (e) before and after the intervention study. P-value [time, group, and interaction (time x group)] of repeated measure analysis of variance. * p < 0.05; ** p < 0.01 for total sample, ö p < 0.05, for women, å p < 0.05 for men, obtained by Student’s paired t-test. Data are shown as means. Abbreviations: SJ, squat jump; CMJ, counter-movement jump; ABKJ, Abalakov jump; DJ, drop jump; T-Beer, the group that performed HIIT and consumed alcohol beer; T-0.0Beer, the group that performed HIIT and consumed non-alcoholic beer; T-Water, the group that performed HIIT and consumed sparkling water; T-Ethanol, the group that performed HIIT and consumed sparkling water with alcohol added

Fig. 4

Changes in maximum oxygen uptake (VO2max.) in absolute (a) and relative terms (b), maximal heart rate (c), and total test duration (d), after the intervention study between the five groups. Significant differences between groups applying an analysis of covariance adjusting for baseline values with post hoc Bonferroni-corrected t-test are indicated as: * p < 0.05 ** p < 0.01, *** p < 0.001. Data are shown as means ± standard error of the mean. Abbreviations: ɳ2, partial eta squared; T-Beer, the group that performed HIIT and consumed alcohol beer; T-0.0Beer, the group that performed HIIT and consumed non-alcoholic beer; T-Water, the group that performed HIIT and consumed sparkling water; T-Ethanol, the group that performed HIIT and consumed sparkling water with alcohol added

Fig. 5

Changes in total hand grip (a), squat jump (b), counter-movement jump (c), Abalakov jump (d), and drop jump (e), after the intervention study between the five groups. Data are shown as means ± standard error of the mean. Abbreviations: ɳ2, partial eta squared; SJ, squat jump; CMJ, counter-movement jump; ABKJ, Abalakov jump; DJ, drop jump; T-Beer, the group that performed HIIT and consumed alcohol beer; T-0.0Beer, the group that performed HIIT and consumed non-alcoholic beer; T-Water, the group that performed HIIT and consumed sparkling water; T-Ethanol, the group that performed HIIT and consumed sparkling water with alcohol added