Anthropometric and performance changes in male college 15s Rugby Union student-athletes over 52 weeks using in-person training and online training supervision.

Background: Although the physiological demands on 15s Rugby Union (RU) players have increased, researchers have suggested that the anthropometric and performance data from developing male college-age RU student-athletes remain limited. This prospective longitudinal repeated measures study aimed to examine the anthropometric and performance changes of male college-age New Zealand Rugby Otago Rugby Football Union (NZRORFU) Academy student-athletes (student-athletes), using in-person and online training supervision (IPTS and OTS, respectively).

Methods: NZRORFU recruited 20 student-athletes (aged 19 to 21 years) and nine were monitored over 52 weeks. During weeks 1 through 35 (in-season), the student-athlete's weekly schedule included 25 hours of IPTS. During the remaining 17 weeks (off-season), the student-athletes followed individualized training programs with OTS. Data were collected on two anthropometric variables and nine performance variables.

Results: Over the 52 weeks, using IPTS and OTS, led to increases in both anthropometric measurements with simultaneous significant performance improvements in vertical jump/lower-body power (7.1%, P=0.005, 95% confidence interval (95% CI) 54.4, 63.5), Cohen's effect size (ES) =medium, upper-body strength, bench-press (17.3%, P=0.005, 95% CI 107.4, 127.6, ES=large), and bench-pull (6.1%, P=0.034, 95% CI 90.4, 96.6, ES=large). Furthermore, performance improvements were observed in two anaerobic endurance variables, however, acceleration and speed results were slower.

Conclusions: The use of IPTS and OTS for 52 weeks resulted in increases in body weight and skinfolds with concurrent significant improvements in the performance of VJ/lower-body power and upper-body strength, but changes in each performance variable occurred at different periods.