(4) RELATIONSHIPS BETWEEN INTERNAL AND EXTERNAL WORKLOAD AND DIFFERENCES BETWEEN MEN AND WOMEN COLLEGIATE VOLLEYBALL ATHLETES

Habitual exposure to repetitive, high-intensity movements is commonplace in volleyball (VB), highlighting the importance of monitoring athlete external workloads in order to manage workload and recovery. Positive associations exist between metrics of internal and external workload in various sport contexts, yet limited data exist relative to VB. Sex differences in the physiological and mechanical profiles across collegiate VB may also exist, with the potential for distinct differences in training volume, match demands, and agreement between internal and external workload.

Purpose: To examine differences in internal and external workload and subsequent associations between men and women collegiate VB athletes.

Methods: National Collegiate Athletic Association Division I athletes from the men’s (MVB, n = 16) and women’s (WVB, n = 17) teams participated. At the start of pre-season, height and body composition were assessed using a stadiometer and air displacement plethysmography, respectively. Athletes wore the same assigned inertial measurement unit during every practice (MVB, n = 20 practices; WVB, n = 30 practices) and match (MVB, n = 18 matches; WVB, n = 16 matches) across a competitive season to capture external workload, measured as jump count (JUMPS). Internal load was determined via surrogate assessment of Rating of Perceived Exertion (RPE; (i.e., Borg CR-10 scale)), which was used to calculate session RPE as the product of post-session RPE and session duration (DUR) (sRPE = RPE x DUR). Statistical analysis was performed using Pearson’s correlation coefficient (r) and repeated measures correlations (rmcorr) to assess between and within-subject associations, respectively. Correlation coefficients were interpreted as: trivial (< 0.1), small (0.1-0.3), moderate (0.3-0.5), large (0.5-0.7), very large ( >0.7). Independent samples t-test was used to determine sex differences in external and internal workload for match, training, and total sessions. Significance was set to p ≤ 0.05.

Results: MVB displayed greater height (p < 0.001) and body mass (p = 0.03), while WVB displayed greater body fat percentage (p < 0.001). In practice only, WVB performed more jumps (p = 0.04) and reported a higher sRPE (p = 0.01) compared to MVB. No differences existed in match workloads between MVB and WVB. Moderate to very large associations were exhibited between JUMPS and sRPE across event type and gender (Table 1).

Conclusions: Differences existed in internal and external workloads in practice with WVB performing higher practice loads. Positive associations existed between internal and external load in MVB and WVB. PRACTICAL APPLICATIONS: Effective load monitoring strategies are recommended to include both jump count and sRPE in collegiate VB athletes. Exposure to workload varies between collegiate MVB and WVB; therefore, sex-specific workload management strategies are warranted.

Acknowledgements: This research was supported by the National Strength and Conditioning Association Foundation grant GRD-2021-02