Rosenblat MA, Perrotta AS, and Vicenzino B. Polarized vs. threshold training intensity distribution on endurance sport performance: A systematic review and meta-analysis of randomized controlled trials. J Strength Cond Res 33(12): 3491–3500, 2019—The objective of this review was to systematically search the literature to identify and analyze data from randomized controlled trials that compare the effects of a polarized training model (POL) vs. a threshold training model (THR) on measurements of sport performance in endurance athletes. This systematic review and meta-analysis is registered with PROSPERO (CRD42016050942). The literature search was performed on November 6, 2016 and included SPORTDiscus (1800–present), CINAHL Complete (1981–present), and Medline with Full Text (1946–present). Studies were selected if they included: random allocation, endurance-trained athletes with greater than 2 years of training experience and Vo ₂max/peak >50 ml·kg·min⁻¹, a POL group, a THR group, assessed either internal (e.g., Vo ₂max) or external (e.g., time trial) measurements of endurance sport performance. The databases SPORTDiscus, Medline and CINAHL yielded a combined 329 results. Four studies met the inclusion criteria for the qualitative analysis, and 3 for the meta-analysis. Two of the 4 studies included in the review scored a 4/10 on the PEDro Scale and 2 scored a 5/10. With respect to outcome measurements, 3 studies included time-trial performance, 3 included Vo ₂max or Vo ₂peak, 2 studies measured time-to-exhaustion, and one study included exercise economy. There was sufficient data to conduct a meta-analysis on time-trial performance. The pooled results demonstrate a moderate effect (ES = −0.66; 95% CI: −1.17 to −0.15) favoring the POL group over the THR group. These results suggest that POL may lead to a greater improvement in endurance sport performance than THR.

The purpose of this investigation was to enhance our understanding of the effects the current British Columbia Wildfire Service (BCWS) firefighting schedule have on the development of fatigue and sleep deprivation. This was a cohort study that objectively and subjectively measured sleep quantity, sleep quality, and fatigue throughout a 17-day British Columbia wildland firefighting deployment. Wildland firefighters (n = 30) conducted daily testing of sleep and fatigue measures during 14 days of activity on the fire line and three days immediately post deployment during their three-day rest period, for a total of 17 days of data collection. Sleep was assessed using wrist-worn actigraphy (ActiGraph LLC, Pensacola, FL) and subjective sleep questionnaires. Fatigue was assessed using subjective fatigue questionnaires and cognitive performance through the psychomotor vigilance test. Total sleep time was less on fire days (M = 6.6 h ± 49.2 min) compared to non-fire days (M = 6.8 h ± 92.2 min). Participants performed poorer on cognitive performance tests, (p = 0.288), and reported being significantly sleepier, (p = 0.038), toward the end of their 17-day deployment compared to day 1. Participants continued to report high levels of sleepiness, fatigue, and poor quality of sleep on their rest days compared to their fire line days. Working 14 consecutive days was associated with increased levels of objective fatigue and suboptimal sleep in wildland firefighters. Wildland firefighters reported significantly higher levels of fatigue and decreased alertness with increasing days on deployment and these levels did not improve following a three-day rest period.

Perrotta, AS, Taunton, JE, Koehle, MS, White, MD, and Warburton, DER. Monitoring the prescribed and experienced heart rate–derived training loads in elite field hockey players. J Strength Cond Res 33(5): 1394–1399, 2019—This study examined the congruence between the prescribed and experienced heart rate–derived training loads over a 5-week periodized mesocycle. Twenty-four elite female field hockey players training as part of a national team were monitored before an (FIH) Hockey World League tournament. Three on-field training sessions per week were prospectively designed focusing on technical, tactical, and physiologically oriented hockey drills. A training load value, modeling the periodized weekly loading scheme, was prescribed for each training session and was calculated using normative training load responses from performing on-field hockey drills. Magnitude-based inferences focusing on the effect size (ES) and a Pearson correlation coefficient (r) were used to examine the degree of difference and the strength of correlation between the prescribed and experienced training loads. A significant correlation was observed between the experienced and prescribed training loads over the 5-week mesocycle (r = 0.92, 90% confidence limit [CL] [0.84–0.96]). The percentage difference and the ES between the achieved and prescribed training loads were as follows: week 1 demonstrated a 2.0% difference (ES = 0.10, 90% CL [−0.22–0.41]), week 2 a −5.4% difference (ES = −0.41, 90% CL [−0.75 to −0.07]), week 3 a −1.5% difference (ES = −0.09, 90% CL [−0.37 to 0.20]), week 4 a 7.1% difference (ES = 0.46, 90% CL [0.14–0.78]), and week 5 a 3.5% difference (ES = 0.18, 90% CL [−0.17 to 0.53]). This investigation demonstrates the efficacy for coaches to prospectively design on-field training sessions using normative training load data to enhance the congruence between the prescribed and experienced training loads over a periodized mesocycle.

This investigation examined the magnitude of correlation between a global marker of exercise stress derived through ratings of perceived exertion (sRPE)- and a heart rate (HR)-derived training load during specific phases of a competitive mesocycle in elite field hockey players. Sixteen (n = 16) female field hockey players training as part of a national team were monitored over a six-week training block consisting of a player selection phase, a preparation phase and a competition phase. HR- and sRPE-derived training loads were recorded for each participant after on-field training sessions and international competition throughout the mesocycle. A significant correlation between sRPE- and HR-derived training loads was observed over the complete mesocycle [r = 0.83, 90% CL (0.77:0.88)]. The selection phase revealed a large correlation [r = 0.54, 90% CL (0.33:0.70], while a very large correlation was observed during the preparatory phase [r = 0.74, 90% CL (0.58:0.85)]. The competition phase revealed a moderate correlation over four international test matches [r = 0.48, 90% CL (0.05:0.70)]. This investigation sheds new light on the varying magnitude of correlation between sRPE- and an HR-derived training load during specific phases of a mesocycle in elite field hockey players training within a national team.

Introduction: Collegiate coaches and integrative support staff often utilize pre-season as a brief and intense training period to prepare athletes technically, tactically, and physiologically, to meet the demands of competition during a soccer season. This study sought to examine the dose-response from performing on-field soccer activities during a four-week pre-season period in female collegiate soccer players, and if the magnitude in response was associated with accumulated exercise stress.Methods: A total of twenty-seven healthy female soccer players training as part of a collegiate soccer program volunteered to participate in this two-year longitudinal study. Data collection commenced prior to the start of each pre-season period, at the beginning of August, and was completed at the beginning of September, when pre-season ended. Data collection periods were separated by a 31-day period. Indices of cardiovascular function, anthropometry, and athletic performance were examined during each data collection period. Internal and external measures of accumulated exercise stress were recorded using the Polar Team Pro® system.Results: When comparing the beginning to the end of pre-season, significant improvements were observed in body fat (%) [24.2 ± 6.0 “vs.” 23.3 ± 5.6, p = 0.001], heart rate variability (rMSSD) [51.8 ± 25.1 “vs.” 67.9 ± 34.6 ms, p = 0.002], resting heart (bpm) [73.8 ± 12.1 “vs.” 64.3 ± 8.8, p = 0.001] and cardiorespiratory performance (YoYo IRTL-1) [925.8 ± 272.8 “vs.” 1,062.6 ± 223.3 m, p = 0.001]. Significant reductions in musculoskeletal performance were observed through vertical jump height (cm) [24.9 ± 23.7, p = 0.04]. Change in the end of pre-season body weight (kg) was significantly associated with accumulated accelerations and decelerations [r ≥ 0.49, p = 0.01]. End of pre-season change in cardiorespiratory performance was significantly associated with both accumulated training load (au) and TRIMP (au) [r ≥ 0.63, p = 0.01].Discussion: In conclusion, performing a four-week pre-season period, involving only on-field training, can promote positive and significant adaptations in anthropometry, cardiovascular function, and athletic performance measures in female collegiate soccer players. The magnitudes of these adaptations were associated with both internal and external measures of accumulated exercise stress.