Manipulation of sprint-bout duration in repeated-sprint training can be used to optimize distinct performance adaptations in young volleyball players, with 3-sec bouts producing greater explosive and sprint gains while 9-sec bouts produced superior change-of-direction and mean power output adaptations.
Key Findings
Results
All repeated-sprint training groups showed significant post-intervention improvements in physical fitness compared to the active control group.
Main effect of time was significant at p = 0.001 across all RST groups
Effect sizes ranged from small to very large across physical fitness measures
The active control group engaged solely in regular volleyball training without RST intervention
The intervention lasted 6 weeks comprising 18 total sessions
40 athletes were randomly allocated across three RST groups (n=10 each) and one control group (n=10)
Results
The 3-second bout group demonstrated greater gains in countermovement vertical jump, 10-m and 20-m sprint performance, reactive strength index, and peak power output compared to the 9-second bout group.
All between-group differences for these measures were statistically significant (all p < 0.05)
The 3-sec group completed two sets of 30 bouts at maximal effort with a 1:3 work-to-rest ratio
These outcomes reflect explosive and sprint performance capacities
Measures assessed included CMVJ, 10-m linear sprint, 20-m linear sprint, RSI, and peak power output from the Wingate anaerobic power test
Results
The 9-second bout group exhibited superior adaptations in T-test change-of-direction speed and mean power output relative to the 3-second bout group.
All between-group differences for these measures were statistically significant (all p < 0.05)
The 9-sec group completed two sets of 10 bouts at maximal effort with a 1:3 work-to-rest ratio
Mean power output was assessed via the Wingate anaerobic power test
Change-of-direction speed was assessed using the T-test (T-CODS)
Methods
The three RST protocols were designed with varying bout durations but similar total repetition volumes and identical work-to-rest ratios.
The 3-sec group performed two sets of 30 bouts (total 60 bouts)
The 6-sec group performed two sets of 15 bouts (total 30 bouts)
The 9-sec group performed two sets of 10 bouts (total 20 bouts)
All groups used a 1:3 work-to-rest ratio and performed efforts at maximal intensity
The study design allowed isolation of bout duration as the primary variable of interest
Methods
Physical fitness assessments included countermovement vertical jump, linear sprint times, change-of-direction speed, reactive strength index, and Wingate anaerobic power test measures.
Tests were conducted pre- and post- the 6-week training intervention
Linear sprint distances assessed were 10-m and 20-m
The Wingate anaerobic power test provided both peak power output and mean power output measures
Reactive strength index (RSI) was included as a measure of stretch-shortening cycle performance
This research suggests that the duration of individual sprint efforts within a repeated-sprint training program meaningfully influences the type of physical improvements young volleyball players experience. In a 6-week study with 40 male volleyball players, participants who trained with very short 3-second sprints got better at explosive jumping, straight-line sprinting, and producing peak bursts of power, while those who trained with longer 9-second sprints improved more in their ability to change direction quickly and sustain power output over time. All sprint training groups improved more than players who only did regular volleyball practice.
The study was carefully designed so that all three sprint groups did a similar overall amount of work — just broken into different chunk sizes — making sprint duration itself the key variable being tested. This allowed the researchers to directly compare how the length of each individual sprint effort shapes the body's adaptations, independent of total training volume.
This research suggests that coaches working with volleyball players or similar athletes can strategically select sprint bout durations based on which physical qualities they most want to develop. Short sprint bouts may be better suited for building explosive power and acceleration, while longer sprint bouts may be more effective for developing agility and sustained anaerobic capacity. Both approaches appear superior to volleyball training alone for improving overall physical fitness.
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Zhang D, Ma L, Li X. (2026). Influence of Repeated-Sprint Bout Duration in Sprint Interval Training Intervention on Physical Performance Adaptations of Young Volleyball Players.. Journal of sports science & medicine. https://doi.org/10.52082/jssm.2026.547