This study compared the physiological and perceptual responses of two high-intensity intermittent aerobic exercises—Hoff Track Exercise (HTE) and the traditional 15s/15s protocol—at matched durations in elite soccer players. Seven male professional soccer players (age: 24.1 ± 4.5 years, height: 175 ± 0.04 cm, body mass: 67.9 ± 9.0 kg, % body fat: 14.2 ± 2.4%) participated in a randomized, within-subject design. Each player completed both exercises over two separate sessions, with a total duration of 25 minutes per session. The 15s/15s protocol involved running at 120% of maximal aerobic speed (MAS), with 15 seconds of active recovery between 4-minute intervals. The HTE required dribbling a soccer ball around a specially designed track (290 m lap), maintaining heart rate between 90–95% of HRmax during each 4-minute work bout, separated by 3 minutes of jogging.
Continuous measurements of oxygen uptake (VO₂) and heart rate (HR) were recorded using a portable telemetric system (VO₂000, Medical Graphics). Blood lactate ([La]) was sampled at rest, pre-exercise, post-warm-up, between sets, and 5 minutes after exercise completion. Rating of Perceived Exertion (RPE) was assessed 15 minutes post-exercise using Borg’s 20-point scale. Data were analyzed using repeated-measures ANOVA with Newman-Keuls post-hoc tests, and effect sizes were calculated.6-Hydroxyindazole InhibitorAnti-infectionParasite
Results showed that mean VO₂ during HTE (39.Pyridostigmine Data Sheet 3 ± 2.PMID:35112631 3 mL/min/kg) was significantly higher than during 15s/15s (36.8 ± 1.9 mL/min/kg; p < 0.05). Total oxygen consumption was also significantly greater during HTE (66.8 ± 7.6 L vs. 62.3 ± 8.6 L; p < 0.05). Blood lactate levels after the first set were significantly elevated in HTE (12.5 ± 2.0 mmol/L) compared to 15s/15s (10.6 ± 2.0 mmol/L; p < 0.05). Despite these higher metabolic demands, RPE scores were significantly lower for HTE (11.7 ± 1.4) than for 15s/15s (13 ± 1.8; p < 0.05). No significant differences were observed in peak HR or mean HR across both conditions. These findings indicate that while HTE elicits greater cardiovascular and metabolic stress—evidenced by higher VO₂ and lactate accumulation—it is perceived as less intense by athletes. This discrepancy may stem from the integration of technical skill (ball control) into the exercise, which may reduce perceived physical strain despite increased physiological load. The results suggest that HTE provides a more effective stimulus for aerobic fitness development due to its superior oxygen utilization and metabolic demand, while maintaining athlete engagement through sport-specific movement patterns. The study supports the use of integrated, soccer-specific training methods like HTE as an effective alternative to conventional interval running for enhancing aerobic endurance in elite footballers. It highlights the importance of combining physical conditioning with technical practice to improve training adherence and performance outcomes. Future research should investigate long-term adaptations and practical implementation strategies in competitive training environments.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com