Abstract
Background: High-intensity interval training (HIIT) is as a time-efficient alternative to moderate- or low-intensity continuous exercise for improving variables related to endurance and anaerobic performance in young and adolescent athletes.Objectives: To assess original research about enhancement of endurance and anaerobic exercise performance in young and adolescent athletes performing HIIT.Method: Relevant articles published in peer-reviewed journals were retrieved from the electronic databases PubMed and SPORTDiscus in December 2017. Inclusion criteria were: (i) controlled trials (HIIT vs. alternative training protocol) with pre-post design; (ii) healthy young athletes (≤18 years); (iii) assessing variables related to endurance and exercise performance. Hedges' g effect size (ES), and associated 95% confidence intervals were calculated for comparison of any outcome between experimental (HIIT) and alternative training protocol.Results: Twenty four studies, involving 577 athletes (mean age: 15.5 ± 2.2 years), were included in this review. HIIT exerted no or small positive mean ES on peak oxygen uptake (VO2peak), running performance, repeated sprint ability, jumping performance and submaximal heart rate. Although the mean ES for changes in VO2peak with HIIT is small (mean g = 0.10±0.28), the average increase in VO2peak from pre to post HIIT-interventions were 7.2 ± 6.9% vs. 4.3 ± 6.9% with any other alternative intervention. HIIT largely and positively affected running speed and oxygen consumption at various lactate- or ventilatory-based thresholds, as well as for sprint running performance. Calculations showed negative mean ES for change-of-direction ability (large), and peak blood lactate concentrations (small). Mean duration per training session for HIIT was shorter than for control interventions (28 ± 15 min vs. 38 ± 24 min).Conclusion: The present findings suggest that young athletes performing HIIT may improve certain important variables related to aerobic, as well as anaerobic, performance. With HIIT, most variables related to endurance improved to a higher extent, compared to alternative training protocols. However, based on ES, HIIT did not show clear superiority to the alternative training protocols. Nevertheless, young athletes may benefit from HIIT as it requires less time per training session leaving more time for training sport specific skills.
Highlights
High-intensity interval training (HIIT) embraces a variety of interval protocols with varying duration and interspersed recovery breaks involving (i) “repeated sprint training” (RST) with sprints of ∼3–7 s duration, interspersed with recovery periods of less than 60 s, (ii) “sprint interval training” (SIT) with ∼30 s all-out sprints, and 2–4 min of passive recovery periods, and (iii) HIIT with either short (
Our analysis revealed that HIIT and SIT has no, or only a small, positive effect [mean g = 0.10 ± 0.28; range: −0.63–0.48 (Helgerud et al, 2001; Impellizzeri et al, 2006, 2008; Hill-Haas et al, 2009; Breil et al, 2010; Sperlich et al, 2010, 2011; Safania et al, 2011; Sandbakk et al, 2011, 2013; Meckel et al, 2014; Harrison et al, 2015a; Fernandez-Fernandez et al, 2017)] on peak oxygen uptake, in comparison to the alternative training protocol (Table 2)
Based on our findings we may conclude that smallsided games are a sufficient training tool to increase the aerobic and anaerobic performance parameters (Buchheit et al, 2009) of young and adolescent team sport athletes, whereas our analyses revealed that HIIT still induces a higher elevation of VO2max than SSG in young athletes
Summary
High-intensity interval training (HIIT) embraces a variety of interval protocols with varying duration and interspersed recovery breaks involving (i) “repeated sprint training” (RST) with sprints of ∼3–7 s duration, interspersed with recovery periods of less than 60 s, (ii) “sprint interval training” (SIT) with ∼30 s all-out sprints, and 2–4 min of passive recovery periods, and (iii) HIIT with either short (
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