The aims of this study were (i) to investigate the criterion validity (vs. gold standard measurements) of the 10 and 18 Hz STATSports Apex units for measuring distances and peak speed (Vpeak) outcomes and (ii) to investigate the between-unit variability. Twenty university students were enrolled in the study (age 21 ± 2 years, weight 72 ± 6 kg, and height 1.76 ± 0.05 m). The criterion validity was tested by comparing the distances recorded by the units with ground truth reference (400-m trial, 128.5-m circuit, and 20-m trial). Vpeak values were compared with those determined by a gold standard criterion device (Stalker ATS Radar Gun) during a linear 20-m sprint. The distance biases for the Apex 10 Hz in the 400-m trial, 128.5-m circuit, and 20-m trial were 1.05 ± 0.87%, 2.3 ± 1.1%, and 1.11 ± 0.99%, respectively, while for the Apex 18 Hz the biases were 1.17 ± 0.73%, 2.11 ± 1.06%, and 1.15 ± 1.23%, respectively. Vpeak measured by the Apex 10 and 18 Hz were 26.5 ± 2.3 km h-1 and 26.5 ± 2.6 km h-1, respectively, with the criterion method reporting 26.3 ± 2.4 km h-1, with a bias of 2.36 ± 1.67% and 2.02 ± 1.24%, respectively. This study is the first to validate and compare the STATSports Apex 10 and 18 Hz. Between-analysis (t-test) for total distance and Vpeak reported non-significant differences. Apex units reported a small error of around 1–2% compared to the criterion distances during 400-m, 128.5-m circuit, 20-m trials, and Vpeak. In conclusion, both units could be used with confidence to measure these variables during training and match play.

Beato, M, Bianchi, M, Coratella, G, Merlini, M, and Drust, B. Effects of plyometric and directional training on speed and jump performance in elite youth soccer players. J Strength Cond Res 32(2): 289-296, 2018-Soccer players perform approximately 1,350 activities (every 4-6 seconds), such as accelerations/decelerations and changes of direction (CODs) during matches. It is well established that COD and plyometric training have a positive impact on fitness parameters in football players. This study analyzed the effect of a complex COD and plyometric protocol (CODJ-G) compared with an isolated COD protocol (COD-G) training on elite football players. A randomized pre-post parallel group trial was used in this study. Twenty-one youth players were enrolled in this study (mean ± SD; age 17 ± 0.8 years, mass 70.1 ± 6.4 kg, and height 177.4 ± 6.2 cm). Players were randomized into 2 different groups: CODJ-G (n = 11) and COD-G (n = 10), training frequency of 2 times a week more than 6 weeks. Sprint 10, 30, and 40 m, long jump, triple hop jump, and 505 COD test were considered. Exercise-induced within-group changes in performance for both CODJ-G and COD-G: long jump (effect size [ES] = 0.32 and ES = 0.26, respectively) and sprint 10 m (ES = -0.51 and ES = -0.22, respectively), after 6 weeks of training. Moreover, CODJ-G reported substantially better results (between-group changes) in long jump test (ES = 0.32). In conclusion, this study showed that short-term protocols (CODJ-G and COD-G) are important and able to give meaningful improvements on power and speed parameters in a specific soccer population. CODJ-G showed a larger effect in sprint and jump parameters compared with COD-G after the training protocol. This study offers important implications for designing COD and jumps training in elite soccer.

The present study investigated the effects of in-season enhanced negative work-based training (ENT) vs weight training in the change of direction (COD), sprinting and jumping ability, muscle mass and strength in semi-professional soccer players. Forty male soccer players participated in the eight-week, 1 d/w intervention consisting of 48 squat repetitions for ENT using a flywheel device (inertia=0.11 kg·m-2) or weight training (80%1 RM) as a control group (CON). Agility T-test, 20+20 m shuttle, 10 m and 30 m sprint, squat jump (SJ) and countermovement jump (CMJ), lean mass, quadriceps and hamstrings strength and the hamstrings-to-quadriceps ratio were measured. Time on agility T-test and 20+20 m shuttle decreased in ENT (effect-size =-1.44, 95% CI -2.24/-0.68 and -0.75, -1.09/-0.42 respectively) but not in CON (-0.33, -0.87/0.19 and -0.13, -0.58/0.32). SJ and CMJ height increased in both ENT (0.71, 0.45/0.97 and 0.65, 0.38/0.93) and CON (0.41, 0.23/0.60 and 0.36, 0.12/0.70). Overall, quadriceps and hamstrings strength increased in both ENT and CON (0.38/0.79), but the hamstrings-to-quadriceps ratio increased in ENT (0.31, 0.22/0.40) but not in CON (0.03, -0.18/0.24). Lean mass increased in both ENT (0.41, 0.26/0.57) and CON (0.29, 0.14/0.44). The repeated negative actions performed in ENT may have led to improvements in braking ability, a key point in COD performance. Semi-professional soccer players may benefit from in-season ENT to enhance COD and the negative-specific adaptations in muscle strength and hamstrings-to-quadriceps ratio.

Beato, M, Stiff, A, and Coratella, G. Effects of postactivation potentiation after an eccentric overload bout on countermovement jump and lower-limb muscle strength. J Strength Cond Res 35(7): 1825-1832, 2021-This study aimed to evaluate the postactivation potentiation (PAP) effects of an eccentric overload (EOL) exercise on countermovement jump (CMJ) performance and isokinetic lower-limb muscle strength. Eighteen active men (mean 6 SD, age 20.2 6 1.4 years, body mass 71.6 6 8 kg, and height 178 6 7 cm) were involved in a randomized, crossover study. The subjects performed 3 sets per 6 repetitions of EOL half squats at maximal power using a flywheel ergometer. Postactivation potentiation using an EOL exercise was compared with a control condition (10-minute cycling at 1 W$kg 21 ). Countermovement jump height, peak power, impulse, and force were recorded at 15 seconds, 1, 3, 5, 7, and 9 minutes after an EOL exercise or control. Furthermore, quadriceps and hamstrings isokinetic strength were performed. Postactivation potentiation vs. control reported a meaningful difference for CMJ height after 3 minutes (effect size [ES] = 0.68, p = 0.002), 5 minutes (ES = 0.58, p = 0.008), 7 minutes (ES = 0.57, p = 0.022), and 9 minutes (ES = 0.61, p = 0.002), peak power after 1 minute (ES = 0.22, p = 0.040), 3 minutes (ES = 0.44, p = 0.009), 5 minutes (ES = 0.40, p = 0.002), 7 minutes (ES = 0.29, p = 0.011), and 9 minutes (ES = 0.30, p = 0.008), as well as quadriceps concentric, hamstrings concentric, and hamstrings eccentric peak torque (ES = 0.13, p = 0.001, ES = 0.24, p = 0.003, and ES = 0.22, p = 003, respectively) after 3-9 minutes of rest. In conclusion, the present outcomes highlight that PAP using an EOL bout improves height, peak power, impulse, and peak force during CMJ, as well as quadriceps and hamstrings isokinetic strength in male athletes. Moreover, the optimal time window for the PAP was found from 3 to 9 minutes.

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Purpose: To summarize the evidence on postactivation potentiation (PAP) protocols using flywheel eccentric overload (EOL) exercises. Methods: Studies were searched using the electronic databases PubMed, Scopus, and Institute for Scientific Information Web of Knowledge. Results: In total, 7 eligible studies were identified based on the following results: First, practitioners can use different inertia intensities (eg, 0.03–0.11 kg·m2), based on the exercise selected, to enhance sport-specific performance. Second, the PAP time window following EOL exercise seems to be consistent with traditional PAP literature, where acute fatigue is dominant in the early part of the recovery period (eg, 30 s), and PAP is dominant in the second part (eg, 3 and 6 min). Third, as EOL exercises require large force and power outputs, a volume of 3 sets with the conditioning activity (eg, half-squat or lunge) seems to be a sensible approach. This could reduce the transitory muscle fatigue and thereby allow for a stronger potentiation effect compared with larger exercise volumes. Fourth, athletes should gain experience by performing EOL exercises before using the tool as part of a PAP protocol (3 or 4 sessions of familiarization). Finally, the dimensions of common flywheel devices offer useful and practical solutions to induce PAP effects outside of normal training environments and prior to competitions. Conclusions: EOL exercise can be used to stimulate PAP responses to obtain performance advantages in various sports. However, future research is needed to determine which EOL exercise modalities among intensity, volume, and rest intervals optimally induce the PAP phenomenon and facilitate transfer effects on athletic performances.

Postactivation potentiation (PAP) mechanisms and responses have a long scientific history. However, to this day there is still controversy regarding the mechanisms underlying enhanced performance after a conditioning activity. More recently, the term postactivation performance enhancement (PAPE) has been proposed with differing associated mechanisms and protocols than with PAP. However, these 2 terms (PAP and PAPE) may not adequately describe all specific potentiation responses and mechanisms and can also be complementary, in some cases. Purpose: This commentary presents and discusses the similarities and differences between PAP and PAPE and, subsequently, elaborates on a new taxonomy for better describing performance potentiation in sport settings. Conclusion: The elaborated taxonomy proposes the formula “Post-[CONDITIONING ACTIVITY] [VERIFICATION TEST] potentiation in [POPULATION].” This taxonomy would avoid erroneous identification of isolated physiological attributes and provide individualization and better applicability of conditioning protocols in sport settings.

Beato, M, Devereux, G, and Stiff, A. Validity and reliability of global positioning system units (STATSports Viper) for measuring distance and peak speed in sports. J Strength Cond Res 32(10): 2831-2837, 2018-Previous evidence has proven that large variability exists in the accuracy of different brands of global positioning systems (GPS). Therefore, any GPS model should be validated independently, and the results of a specific brand cannot be extended to others. The aim of this study is to assess the validity and reliability of GPS units (STATSports Viper) for measuring distance and peak speed in sports. Twenty participants were enrolled (age 21 ± 2 years [range 18 to 24 years], body mass 73 ± 5 kg, and height 1.78 ± 0.04 m). Global positioning system validity was evaluated by comparing the instantaneous values of speed (peak speed) determined by GPS (10 Hz, Viper Units; STATSports, Newry, Ireland) with those determined by a radar gun during a 20-m sprint. Data were analyzed using the Stalker (34.7 GHz, USA) ATS Version 5.0.3.0 software as gold standard. Distance recorded by GPS was also compared with a known circuit distance (400-m running, 128.5-m sports-specific circuit, and 20-m linear running). The distance bias in the 400-m trial, 128.5-m circuit, and 20-m trial was 1.99 ± 1.81%, 2.7 ± 1.2%, and 1.26 ± 1.04%, respectively. Peak speed measured by the GPS was 26.3 ± 2.4 km·h, and criterion was 26.1 ± 2.6 km·h, with a bias of 1.80 ± 1.93%. The major finding of this study was that GPS did not underestimate the criterion distance during a 400-m trial, 128.5-m circuit, and 20-m trial, as well as peak speed. Small errors (<5%, good) were found for peak speed and distances. This study supported the validity and reliability of this GPS model.