• Associations between selected training stress measures and fitness changes in male soccer players

      Rabbani, Alireza; Kargarfard, Mehdi; Castagna, Carlo; Clemente, Filipe M.; Twist, Craig; University of Chester (Human Kinetics, 24/01/2019)
      Purpose: The purpose of this study was to investigate the relationship of accumulated Global Positioning System (GPS)-accelerometer-based and heart rate (HR)-based training metrics to changes in high-intensity intermittent running capacity during an in-season phase in professional soccer players. Method: Eleven male professional players (mean ± SD, age: 27.2 ± 4.5 years) performed the 30-15 Intermittent Fitness Test (30-15IFT) before and after a five-week in-season training phase, and the final velocity (VIFT) was considered as players’ high-intensity intermittent running capacity. During all sessions, Edwards’ training impulse (Edwards’ TRIMP), Banister’s TRIMP, Z5 TRIMP, training duration, total distance covered, New Body Load (NBL), high-intensity running performance (distance covered above 14.4 km•h-1), and very high-intensity running performance (distance covered above 19.8 km•h-1) were recorded. Results: The players’ VIFT showed a most likely moderate improvement (+4.3%, 90% confidence limits [3.1; 5.5%], effect size ES, 0.70 [0.51; 0.89]). Accumulated NBL, Banister’s TRIMP and Edwards’ TRIMP showed large associations (r = 0.51 to 0.54) with changes in VIFT. Very large relationship was also observed between accumulated Z5 TRIMP (r= 0.72) with changes in VIFT. Large-to-nearly perfect within-individual relationships were observed between NBL and some of the other training metrics (i.e., Edwards’ TRIMP, Banister’s TRIMP, training duration, and total distance) in 10 out of 11 players. Conclusions: HR-based training metrics can be used to monitor high-intensity intermittent running capacity changes in professional soccer players. The dose-response relationship is also largely detected using accelerometer-based metrics (i.e., NBL) to track changes in high-intensity intermittent running capacity of professional soccer players.
    • Fitness Monitoring in Elite Soccer Players: Group vs. Individual Analyses.

      Rabbani, Alireza; Kargarfard, Mehdi; Twist, Craig (14/06/2018)
      Rabbani, A, Kargarfard, M, and Twist, C. Fitness monitoring in elite soccer players; group vs. individual analyses. J Strength Cond Res XX(X): 000-000, 2018-The aims of this study were to (a) examine changes in group and individual HR measures during a submaximal warm-up test, and (b) investigate the relationship between accumulated internal training loads and HR changes during an in-season phase among elite soccer players (n = 14). Before and after an in-season phase (24 days), exercise HR (HRex) and HR recovery (HRR) expressed either as the number of beats recovered (HRR60s) or as the mean HR (HRpost1) during 1 minute of recovery were analyzed. Heart rate measures were expressed as the % of maximal HR. Session rating of perceived exertion (sRPE) was computed for all training/match sessions. Group and individual HR changes were analyzed using magnitude-based inferences. Pearson correlation coefficients were also used to examine the relationships. Group analyses of HR changes revealed there were possibly to likely trivial changes in all HR measures. When analyzing individual data, no substantial change was observed for HRR60s%. However, substantial changes in HRex% and HRpost1% were observed for 4/14 and 5/14 players, respectively. The relationships between HRex% and HRpost1% were nearly perfect (r = 0.90, confidence limits [0.82-0.95]). The associations between changes in HRex% and HRpost1% were also nearly perfect (r = 0.92, 0.80-0.97). A very large inverse correlation was observed between HRex% and accumulated sRPE (r = -0.75, -0.44 to -0.90). This study highlights the value of conducting individual vs. group aerobic fitness monitoring. This study also showed the importance of how HRR is reported when aerobic fitness monitoring of elite soccer players.
    • The Reliability and Validity of A Submaximal Warm-Up Test for Monitoring Training Status in Professional Soccer Players.

      Rabbani, Alireza; Kargarfard, Mehdi; Twist, Craig; University of Isfahan; University of Chester (Lippincott, Williams & Wilkins, 27/11/2017)
      Two studies were conducted to assess the reliability and validity of a submaximal warm-up test (SWT) in professional soccer players. For the reliability study, 12 male players performed SWT over three trials, with one week between trials. For the validity study, 14 players of the same team performed SWT and 30-15 Intermittent Fitness Test (30-15IFT) 7 days apart. Week-to-week reliability in selected heart rate (HR) responses [exercise HR (HRex), HR recovery (HRR) expressed as the number of beats recovered within 1 min (HRR60s) and expressed as the mean HR during 1 min (HRpost1)], were determined using intraclass correlation coefficient (ICC) and typical error of measurement expressed as coefficient of variation (CV). The relationships between HR measures derived from SWT and the maximal speed reached at the 30-15IFT (VIFT) were used to assess validity. The range for ICC and CV values were 0.83 to 0.95 and 1.4 to 7.0% in all HR measures, respectively, with the HRex as the most reliable HR measure of SWT. Inverse large (r = -0.50, 90% confidence limits, CL (-0.78; -0.06)) and very large (r = -0.76, CL, -0.90; -0.45) relationships were observed between HRex and HRpost1 with VIFT in relative (expressed as the % of maximal HR) measures, respectively. SWT is a reliable and valid submaximal test to monitor high-intensity intermittent running fitness in professional soccer players. In addition, the test’s short duration (5-min) and simplicity mean that it can be used regularly to assess training status in high-level soccer players.