1. The Relationship Among Vertical Jump Height, Sprint Time, and Fatigue Index in College Students. 2. The Relationship Between Performance Characteristics of the Countermovement Jump and a Maximal Sprint.

Abstract 1: Peak anaerobic performance and anaerobic capacity are both important parameters in sports, especially those requiring short duration maximal efforts. Previous researchers have found a significant relationship between the vertical jump and sprint performance. However, there is limited research on the relationship between peak anaerobic performance and resistance to fatigue. PURPOSE: The purpose of this study was to compare peak jumping and sprinting performance to fatigue index (FI) during the running-based anaerobic sprint test (RAST). METHODS: Apparently healthy, active college-aged males and females (n = 18, age = 20.7 ± 1.1 yrs, height = 171.4 ± 7.8 cm, mass = 70.3 ± 15.4 kg) participated in this study. Following a standardized warmup, participants completed three maximal countermovement jumps (CMJs) interspersed with 30-60 sec of rest. Reach and peak jump heights were measured using a Vertec Jump Trainer with jump height (JH) calculated as the difference between standing reach height and peak jump reach height. A Tendo Weightlifting Analyzer recorded peak concentric values for jumping power (PPJ), velocity (PVJ), and force (PFJ) during the jumps. The Tendo was attached to the back of a vest in a position just superior to the waist. The jump with the greatest JH was used for analysis. Following CMJ testing, participants completed the RAST, which involves 6 maximal 35-meter sprints interspersed with 10 seconds of recovery. Sprint time was recorded and used to calculate mean velocity (MVS), force (MFS), and power (MPS) for all sprints, with force, velocity, and power from the fastest sprint used for analysis. FI was calculated as (max sprint power – minimum sprint power)/ total sprint time. Pearson product-moment correlations assessed the relationship between peak jump and sprint measures and FI (p \u3c 0.05). RESULTS: Strong linear relationships were noted between FI and MPS (r = 0.91, p \u3c 0.001), FI and MVS (r = 0.85, p \u3c 0.001), and FI and MFS (r = 0.837, p \u3c 0.001), indicating that a greater FI was present in those with greater maximal single sprint performance. Moderate correlations were found between FI and peak CMJ variables (PVJ: r = 0.54, p = 0.02; JH: r = 0.50, p = 0.036). Modest, non-significant correlations were found between FI and PPJ (r = 0.45, p = 0.062) and FI and PFJ (r = 0.32, p = 0.19). Body mass (BM) was not a significant predictor of FI (r = 0.24, p = 0.34). CONCLUSION: Participants with greater sprint force, velocity, and power also had a higher degree of fatigue during the RAST. Similarly, those with greater CMJ velocity and JH also had a greater FI. BM did not appear to influence rate of fatigue, as BM and FI weakly correlated. Therefore, greater peak anaerobic performance did not predict resistance to fatigue as they appear to be positively correlated. Training status and subject heterogeneity may have contributed to these data. PRACTICAL APPLICATION: As peak anaerobic capacity and fatigue index are both important parameters in sport and fitness performance, coaches and practitioners should analyze these factors separately. As those with greater maximal anaerobic performance also fatigued to a greater degree, training programs should emphasize desired adaptations. Abstract 2: The countermovement jump (CMJ) is often used to measure lower body power and athletic performance. The CMJ has been positively correlated with shorter distance sprinting (10m), likely due to the short duration maximal efforts required by both activities. Therefore, the CMJ may be useful in assessing sprint-related performance metrics during training. PURPOSE: The purpose of this study was to assess the relationship between CMJ and 35-meter sprint performances. METHODS: Apparently healthy, active college-aged males and females (n = 18, age = 20.7 ± 1.1 yrs, height = 171.4 ± 7.8 cm, mass = 70.3 ± 15.4 kg) participated in this study. Following a standardized warmup, participants completed maximal CMJ and sprint testing. Participants completed three maximal CMJs interspersed with 30-60 seconds of rest. Reach and peak jump heights were measured using a Vertec Jump Trainer, with jump height (JH) calculated as the difference between standing reach height and peak jump reach height. A Tendo Weightlifting Analyzer recorded peak concentric values for jumping power (PPJ), velocity (PVJ), and force (PFJ) during the jumps. The Tendo Unit was attached to the back of a vest in a position just superior to the waist. The jump with the greatest JH was used for analysis. Following CMJ testing, participants completed six maximal 35-meter sprints, with the fastest sprint used for analysis. Time to completion was recorded and used to calculate mean velocity (MVS) across the duration of the sprint. Pearson product-moment correlations were used to assess the relationship between CMJ and MVS (p \u3c 0.05). RESULTS: Strong linear correlations were noted between PVJ and MVS (r = 0.77, p \u3c 0.001) and JH and MVS (r = 0.76, p \u3c 0.001). Respective r-squared values were 0.59 and 0.58, indicating a substantial amount of the variance in sprinting performance can be explained by peak CMJ velocity or jump height. In addition, PVJ and JH share very strong correlations (r = 0.90, p \u3c 0.05). PPJ and MVS shared a moderate correlation (r = 0.61, p = 0.008), while PFJ and MVS were not significantly related (r = 0.31, p = 0.21). PFJ was also not a strong predictor of JH (r = 0.37, p = 0.13). CONCLUSION: PVJ and JH were very strong predictors of sprinting velocity. As both sprinting and jumping require short duration maximal efforts, the ability to achieve high concentric velocity during explosive activities may be indicative of performance. PPJ also shared a strong correlation with sprint velocity; however, PFJ was not significantly related to sprinting performance or jump height. Since velocity is a component of power, this relationship may explain why PPJ shares a strong relationship with sprint performance. As such, jumping performance appears to be related to sprinting velocity, and CMJ metrics may be a simplistic, economical test to monitor and assess athletic performance. PRACTICAL APPLICATION: Coaches and practitioners often assess and monitor athlete performance. Sprint testing may not always be feasible due to space and time constraints. The CMJ appears to be a method that can monitor sprint-related performance metrics