The purpose of this study was to compare jumping capacity after performing the "Université de Montréal Track Test" (UMTT) and the time limit (Tlim) at maximal aerobic speed. At the end of the competitive season, 12 well-trained male endurance runners performed the UMTT and Tlim tests on 2 different days separated by 48 hours to 7 days. Countermovement jump (CMJ) performance was assessed before and at the second and seventh minute after the 2 running protocols. An enhanced CMJ was observed at the second minute of recovery after UMTT and Tlim (p = 0.000; p = 0.015, respectively) and remained elevated only after the UMTT (p = 0.000). No significant correlations were found between jump and endurance field running performance. It is concluded that the postactivation potentiation profile after fatiguing running exercises in distance runners is protocol dependent with the mechanism yet to be determined.

Purpose: Countermovement jump (CMJ) and maximum running speed over a distance of 20 m were evaluated for examination of the concurrent fatigue and postactivation potentiation (PAP) in endurance athletes after an incremental field running test. Methods: Twenty-two endurance athletes performed two attempts of CMJ on a force plate and maximum running speed test before and following the Université de Montréal Track Test (UMTT). Results: The results showed an improvement in CMJ height (3.6%) after UMTT that correlated with the increment in peak power (3.4%), with a concurrent peak force loss (-10.8%) that correlated with peak power enhancement. The athletes maintained their 20 m sprint performance after exhaustion. Cluster analysis reinforced the association between CMJ and peak power increments in responders with a reported correlation between peak power and sprint performance increments (r = .623; P = .041); nonresponders showed an impairment of peak force, vertical stiffness, and a higher vertical displacement of the center of mass during the countermovement that correlated with lactate concentration (r = -0.717; P = .02). Conclusions: It can be suggested that PAP could counteract the peak force loss after exhaustion, allowing the enhancement of CMJ performance and the maintenance of sprint ability in endurance athletes after the UMTT. From these results, the evaluation of CMJ after incremental running tests for the assessment of muscular adaptations in endurance athletes can be recommended.

Varela-Sanz, A, Tuimil, JL, Abreu, L, and Boullosa, DA. Does concurrent training intensity distribution matter? J Strength Cond Res 31(1): 181-195, 2017-Previous research has demonstrated the influence of intensity distribution on endurance training adaptations. However, no study has addressed the influence of intensity distribution on the effectiveness of concurrent training (CT). The main objective of this study was to compare the effects of 2 CT programs with different training intensity distribution and externally equated loads on physical fitness. Thirty-one sport science students volunteered and were evaluated for resting heart rate variability (HRV), countermovement jump, bench press, half squat, and maximum aerobic speed (MAS). All were randomly distributed into either a traditional-based training group (TT; n = 11; 65-75% of MAS, combined with 10-12 repetition maximum [RM]), polarized training group (PT; n = 10; 35-40% and 120% of MAS, combined with 5RM and 15RM), or control group (CG; n = 10). After 8 weeks of training (3 daysweek), TT and PT exhibited similar improvements in MAS, bench press, and half squat performances. No differences were observed between TT and PT groups for perceived loads. There were no changes in HRV for any group, although TT exhibited a reduction in resting heart rate. Compared with other groups, the PT group maintained jump capacity with an increment in body mass and body mass index without changes in body fatness. In conclusion, PT induced similar improvements in physical fitness of physically active individuals when compared with TT. However, PT produced a lower interference for jumping capacity despite an increment in body mass, whereas TT induced greater bradycardia. Extended studies with different intensity distributions should be conducted to better determine the dose-response of CT in various populations.

The purpose of this study was to assess the effect of a soccer match on the cardiac autonomic control of heart rate (HR) in soccer referees. Sixteen Spanish regional and third division referees (11 males: 26 ± 7 years, 74.4 ± 4.1 kg, 178 ± 3 cm, Yo-Yo IR1 ~600-1,560 m; 5 females: 22 ± 3 years, 59.3 ± 4.8 kg, 158 ± 8 cm, Yo-Yo IR1 ~200-520 m) participated with 24-h HR recordings measured with a Polar RS800 during a rest and a match day. Autonomic control of HR was assessed from HR variability (HRV) analysis. Inclusion of a soccer match (92.5% spent at >75% maximum HR) reduced pre-match (12:00-17:00 hours; small to moderate), post-match (19:00-00:00 hours; moderate to almost perfect), and night-time (00:00-05:00 hours; small to moderate) HRV. Various moderate-to-large correlations were detected between resting HRV and the rest-to-match day difference in HRV. The rest-to-match day differences of low and high-frequency bands ratio (LF/HF) and HR in the post-match period were moderately correlated with time spent at different exercise intensities. Yo-Yo IR1 performance was highly correlated with jump capacity and peak lactate, but not with any HRV parameter. These results suggest that a greater resting HRV may allow referees to tolerate stresses during a match day with referees who spent more time at higher intensities during matches exhibiting a greater LF/HF increment in the post-match period. The relationship between match activities, [Formula: see text] and HR recovery kinetics in referees and team sport athletes of different competitive levels remains to be clarified.

This study examined the relationships between basal heart rate (BHR) and heart rate recovery (HRR), parasympathetic modulation parameters, with running performance in distance runners. It was hypothesized that greater parasympathetic modulation would be significantly associated with greater running performance. Twelve well-trained endurance runners (23.2 +/- 3.3 years; 175.6 +/- 5.8 cm; 65.2 +/- 6.7 kg) performed the Université de Montréal Track Test (UMTT) until volitional exhaustion (total final time, TUMTT), with the highest completed stage recorded as the maximal aerobic speed (MAS). More than 48 hours afterwards, participants ran at the MAS until volitional exhaustion, with maximal running time (Tlim) recorded. Maximum heart rate was significantly greater for the UMTT compared with Tlim (p = 0.004). Significant correlations were exhibited between MAS and BHR (r = -0.845, p = 0.001); mean drop in heart rate at the first minute of recovery after the UMTT (r = 0.617, p = 0.033) and Tlim (r = 0.787, p = 0.002); and mean drop in heart rate at the second minute of recovery after the UMTT (r = 0.630, p = 0.028). These results support previous reports that endurance training results in greater running performance and greater parasympathetic modulation before and after exercise. We suggest that coaches consider HRR and BHR for the monitoring of training for endurance performance.