Purpose: To quantify the impact of training-intensity distribution on 10K performance in recreational athletes.Methods: 30 endurance runners were randomly assigned to a training program emphasizing low-intensity, sub-ventilatory-threshold (VT), polarized endurance-training distribution (PET) or a moderately high-intensity (between-thresholds) endurance-training program (BThET). Before the study, the subjects performed a maximal exercise test to determine VT and respiratory-compensation threshold (RCT), which allowed training to be controlled based on heart rate during each training session over the 10-wk intervention period. Subjects performed a 10-km race on the same course before and after the intervention period. Training was quantified based on the cumulative time spent in 3 intensity zones: zone 1 (low intensity, RCT). The contribution of total training time in each zone was controlled to have more low-intensity training in PET (±77/3/20), whereas for BThET the distribution was higher in zone 2 and lower in zone 1 (±46/35/19).Results: Both groups significantly improved their 10K time (39min18s ± 4min54s vs 37min19s ± 4min42s, P < .0001 for PET; 39min24s ± 3min54s vs 38min0s ± 4min24s, P < .001 for BThET). Improvements were 5.0% vs 3.6%, ~41 s difference at post-training-intervention. This difference was not significant. However, a subset analysis comparing the 12 runners who actually performed the most PET (n = 6) and BThET (n = 16) distributions showed greater improvement in PET by 1.29 standardized Cohen effect-size units (90% CI 0.31–2.27, P = .038).Conclusions: Polarized training can stimulate greater training effects than between-thresholds training in recreational runners.

Hamstring strain and anterior cruciate ligament injuries are, respectively, the most prevalent and serious non-contact occurring injuries in team sports. Specific biomechanical and neuromuscular variables have been used to estimate the risk of incurring a non-contact injury in athletes. The aim of this study was to systematically review the evidences for the effectiveness of injury prevention protocols to modify biomechanical and neuromuscular anterior cruciate and/or hamstring injuries associated risk factors in uninjured team sport athletes. PubMed, Science Direct, Web of Science, Cochrane Libraries, U.S. National Institutes of Health clinicaltrials.gov, Sport Discuss and Google Scholar databases were searched for relevant journal articles published until March 2015. A manual review of relevant articles, authors, and journals, including bibliographies was performed from identified articles. Nineteen studies were included in this review. Four assessment categories: i) landing, ii) side cutting, iii) stop-jump, and iv) muscle strength outcomes, were used to analyze the effectiveness of the preventive protocols. Eight studies using multifaceted interventions supported by video and/or technical feedback showed improvement in landing and/or stop-jump biomechanics, while no effects were observed on side-cutting maneuver. Additionally, multifaceted programs including hamstring eccentric exercises increased hamstring strength, hamstring to quadriceps functional ratio and/or promoted a shift of optimal knee flexion peak torque toward a more open angle position. Multifaceted programs, supported by proper video and/or technical feedback, including eccentric hamstring exercises would positively modify the biomechanical and or neuromuscular anterior cruciate and/or hamstring injury risk factors.

Purpose: To describe training loads during an Ironman training program based on intensity zones and observe training–performance relationships.Methods: Nine triathletes completed a program with the same periodization model aiming at participation in the same Ironman event. Before and during the study, subjects performed ramp-protocol tests, running, and cycling to determine aerobic (AeT) and anaerobic thresholds (AnT) through gas-exchange analysis. For swimming, subjects performed a graded lactate test to determine AeT and AnT. Training was subsequently controlled by heart rate (HR) during each training session over 18 wk. Training and the competition were both quantified based on the cumulative time spent in 3 intensity zones: zone 1 (low intensity; AnT).Results: Most of training time was spent in zone 1 (68% ± 14%), whereas the Ironman competition was primarily performed in zone 2 (59% ± 22%). Significant inverse correlations were found between both total training time and training time in zone 1 vs performance time in competition (r = –.69 and –.92, respectively). In contrast, there was a moderate positive correlation between total training time in zone 2 and performance time in competition (r = .53) and a strong positive correlation between percentage of total training time in zone 2 and performance time in competition (r = .94).Conclusions: While athletes perform with HR mainly in zone 2, better performances are associated with more training time spent in zone 1. A high amount of cycling training in zone 2 may contribute to poorer overall performance.

The aim of this study was to compare the effects of 3 different volume of resistance training (RT) on maximum strength and average power in college team sport athletes with no previous RT experience. Thirty-two subjects (20 men and 12 women, age = 23.1 ± 1.57 years) were randomly divided into 4 groups: low volume (LV; n = 8), 1 set per exercise and 3 sets per muscle group; moderate volume (MV; n = 8), 2 sets per exercise and 6 sets per muscle group; high volume (HV; n = 8), 3 sets per exercise and 9 sets per muscle group; and a non-RT control group (n = 8). The 3 intervention groups were trained for 6 weeks thrice weekly after a nonperiodized RT program differentiated only by the volume. Before (T1) and after training (T2), 1 repetition maximum (1RM) and maximal average power (AP) produced on the bench press (BP), upright row (UR), and squat (SQ) were assessed by progressive resistance tests. One repetition maximum-BP and 1RM-UR increased significantly in the 3 interventions groups (p < 0.05), whereas only the HV group significantly improved 1RM-SQ (p < 0.01). The MV and HV groups increased AP-BP (p < 0.05), whereas only the LV group improved AP-SQ (p < 0.01). Moderate effect sizes (ES; >0.20 < 0.60) were observed for the 1RM-BP and 1RM-UR in the 3 training groups. High-volume group showed the larger ES for 1RM-BP (0.45), 1RM-UR (0.60), and 1RM-SQ (0.47), whereas the LV produced the higher ES for SQ-AP (0.53). During the initial adaptation period, a HV RT program seems to be a better strategy for improving strength, whereas during the season, an LV RT could be a reasonable option for maintaining strength and enhancing lower-body AP in team sport athletes.