Template-Type: ReDIF-Article 1.0
Title: EFFECTS OF HIGH-INTENSITY INTERVAL TRAINING ON CARDIORESPIRATORY FITNESS AND MUSCULAR ENDURANCE IN UNIVERSITY ATHLETES: A RANDOMIZED CONTROLLED TRIAL
Author-Name: Karimov Bekzod Boyqobilovich
Author-Email: bekzodk442@gmail.com
Author-Workplace-Name: University of Economy and pedagogy
Abstract: High-intensity interval training (HIIT) has emerged as a time-efficient exercise modality; however, its dose-response relationship on multiple fitness components in collegiate athletes remains insufficiently characterized. Objectives: This study aimed to evaluate the effects of an 8-week HIIT programme on cardiorespiratory fitness (VO₂max), muscular endurance, lactate threshold, and body composition in university-level athletes compared to moderate-intensity continuous training (MICT). Methods: Sixty-four (n = 64) university athletes (mean age 20.3 ± 1.8 years) were randomly assigned to HIIT (n = 32) or MICT (n = 32) groups. The HIIT protocol consisted of 4 × 4-minute intervals at 90-95% HRmax with 3-minute active recovery periods, 3 sessions per week. Primary outcomes included VO₂max (ml·kg⁻¹·min⁻¹), muscular endurance index (MEI), and blood lactate concentration. Pre- and post-intervention assessments were conducted under standardized laboratory conditions. Results: The HIIT group demonstrated significantly greater improvements in VO₂max (Δ+5.6 ml·kg⁻¹·min⁻¹, 95% CI: 4.2-7.0, p < 0.001, d = 1.12) and MEI (Δ+18.3%, p < 0.001) compared to MICT (VO₂max Δ+2.9 ml·kg⁻¹·min⁻¹, p = 0.004). Body fat percentage decreased by 3.1 ± 0.8% in HIIT versus 1.4 ± 0.6% in MICT (p < 0.001). Conclusions: An 8-week HIIT protocol produced superior gains in cardiorespiratory fitness and muscular endurance compared to MICT in collegiate athletes. These findings support the integration of structured HIIT into university-level sports conditioning programs.
Keywords: high-intensity interval training; VO₂max; physical education; athletic performance; cardiorespiratory fitness; muscular endurance; lactate threshold; body composition
Creation-Date: 2026-04-01
Journal: Synoptic: International Journal of Multidisciplinary Research
Volume: 1
Issue: 1
Pages: 10-18
File-URL: https://lmhqneinkzpxfhahvcvx.supabase.co/storage/v1/object/public/pdfs/articles/1777546664824-10-18.pdf
File-Format: Application/pdf
Handle: RePEc:snp:journl:art-1777542910741