title: High-intensity interval training every second week maintains VO2max in soccer players during off-season.
abstract: Reduced endurance training among semiprofessional soccer players during off-season may have negative effect on game performance during the competition season. This negative effect can be prevented by adding high-intensity interval training (HIT) to normal activity. In this study, we want to compare 2 different frequencies of HIT (5 bouts of 4 minutes on 87-97% peak heart rate) session on maintenance of aerobic fitness among semiprofessional soccer players during a 6-week off-season period. Seventeen male players at second and third highest soccer division in Norway participated. The subjects were randomized into 1 HIT session every second week (HIT 0.5) or 1 HIT session per week (HIT 1). All participants performed a 20-m shuttle run test and a maximal oxygen uptake (VO2max) test on treadmill before and after the training intervention. VO2max (HIT 0.5, 63.4 ± 5.9 ml·kg-1·min-1; HIT 1, 65.6 ± 2.1 ml·kg-1·min-1) and 20-m shuttle run performance (HIT 0.5, 2335 ± 390 m, HIT 1, 2531 ± 106 m) were not different between the groups before the training intervention. VO2max was maintained after the training intervention in both HIT 0.5 and HIT 1 (64.0 ± 5.9 ml·kg-1·min-1 and 64.3 ± 1.3 ml·kg-1·min-1, respectively). There was a reduction in distance covered during the 20-m shuttle run test in HIT 1 and when groups were pooled (-7.9 ± 5.7% and -6.4 ± 7.9%, respectively, p ≤ 0.05). In conclusion, HIT 1 did not maintain VO2max better than HIT 0.5 when added to normal off-season activity. However, performance in 20-m shuttle run, which is a more soccer-specific fitness test than VO2max test, was slightly reduced when both groups was pooled.
authors.affiliation: Section for Sport Science, Lillehammer University College, Lillehammer, Norway.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Slettaløkken
authors.forename: Bent R
authors.initials: BR
authors.lastname: Rønnestad
mesh_terms: D000293:Adolescent; D000328:Adult; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods* / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D011659:Pulmonary Gas Exchange; D012916:Soccer / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D019344:Lactic Acid