scholarly journals Effects of Post-Activation Performance Enhancement (PAPE) Induced by a Plyometric Protocol on Deceleration Performance

2021 ◽  
Vol 80 (1) ◽  
pp. 5-16
Author(s):  
Gianmarco Ciocca ◽  
Harald Tschan ◽  
Antonio Tessitore

Abstract Post-Activation Potentiation (PAP) is a phenomenon which can improve power performance executed after a previous conditioning activity. PAP is usually evoked through heavy resistance or plyometric exercise. It has been suggested to refer to as Postactivation Performance Enhancement (PAPE) when research is field-based on explosive activities. To our best knowledge, no studies have investigated the effects of PAPE on deceleration performance, which is a key factor in sports involving change of directions. Therefore, the aim of this study was to investigate the influence of a plyometric exercise protocol on a subsequent deceleration running performance. University soccer players (n = 18) performed seven deceleration trials and were assessed at baseline and after ~15 s, 2, 4, 8, 12 and 16 min either following a walking control condition (C) or three sets of ten repetitions of alternate-leg bounding (plyometric, P). Results showed no significant differences at any of the trials under the control condition (C) in comparison to the relative baseline. Under the plyometric condition (P), deceleration performance executed two minutes after the plyometric activity resulted in significantly faster results compared to the baseline values (p = 0.042; ES = 0.86, large effect; % of improvement = 4.13 %). The main findings are that plyometric exercise improves a subsequent running deceleration performance, 2 min after its execution. Future investigations should focus on more complex actions such as changes of direction and agility.

2019 ◽  
Author(s):  
Gianmarco Ciocca ◽  
Harald Tschan ◽  
Antonio Tessitore

AbstractPost-Activation Potentiation is a phenomenon by which muscular performance characteristics are acutely enhanced as a result of their previous contractile actions. It has been shown how Post-Activation Potentiation, which is usually evoked through heavy resistance exercise, has the potential to improve many different power performances, such as sprinting and jumping. Due to an easier applicability, some studies explored the potential of plyometric muscular actions to evoke the effects of Post-Activation Potentiation. Despite some findings on acceleration running performance, to the authors’ best knowledge, no studies investigated the effects of Post-Activation Potentiation on deceleration performance, which is a key factor in sports involving change of directions. Therefore, the aim of this study is to investigate the influence of a plyometric exercise protocol to a subsequent deceleration running performance. University soccer players (n = 18) performed 7 deceleration trials: at baseline and after ∼ 15 seconds, 2, 4, 8, 12 and 16 minutes a walking control condition (C) or 3 sets of 10 repetitions of alternate-leg bounding (plyometric, P). Results show that no significant differences were found at any of the trials of the control condition (C) in comparison to the relative baseline. In the plyometric condition (P), the deceleration performance executed 2 minutes after the plyometric activity resulted significantly faster compared to the relative baseline (p = 0.042; ES = 0.86, large effect; % of improvement = 4.13 %). Therefore, the main findings of this study showed that a plyometric exercise has the potential to improve a subsequent running deceleration performance in soccer players, if an adequate recovery between these activities is provided to the players. These findings encourage further future investigations about the possible potentiating effects of plyometric activities on more complex actions like changes of direction and agility.


Author(s):  
Carlos Lago-Peñas ◽  
Anton Kalén ◽  
Miguel Lorenzo-Martinez ◽  
Roberto López-Del Campo ◽  
Ricardo Resta ◽  
...  

This study aimed to evaluate the effects playing position, match location (home or away), quality of opposition (strong or weak), effective playing time (total time minus stoppages), and score-line on physical match performance in professional soccer players using a large-scale analysis. A total of 10,739 individual match observations of outfield players competing in the Spanish La Liga during the 2018–2019 season were recorded using a computerized tracking system (TRACAB, Chyronhego, New York, USA). The players were classified into five positions (central defenders, players = 94; external defenders, players = 82; central midfielders, players = 101; external midfielders, players = 72; and forwards, players = 67) and the following match running performance categories were considered: total distance covered, low-speed running (LSR) distance (0–14 km · h−1), medium-speed running (MSR) distance (14–21 km · h−1), high-speed running (HSR) distance (>21 km · h−1), very HSR (VHSR) distance (21–24 km · h−1), sprint distance (>24 km · h−1) Overall, match running performance was highly dependent on situational variables, especially the score-line condition (winning, drawing, losing). Moreover, the score-line affected players running performance differently depending on their playing position. Losing status increased the total distance and the distance covered at MSR, HSR, VHSR and Sprint by defenders, while attacking players showed the opposite trend. These findings may help coaches and managers to better understand the effects of situational variables on physical performance in La Liga and could be used to develop a model for predicting the physical activity profile in competition.


2021 ◽  
Vol 13 (13) ◽  
pp. 7025
Author(s):  
Shiva Gorjian ◽  
Behnam Hosseingholilou ◽  
Laxmikant D. Jathar ◽  
Haniyeh Samadi ◽  
Samiran Samanta ◽  
...  

The food industry is responsible for supplying the food demand of the ever-increasing global population. The food chain is one of the major contributors to greenhouse gas (GHG) emissions, and global food waste accounts for one-third of produced food. A solution to this problem is preserving crops, vegetables, and fruits with the help of an ancient method of sun drying. For drying agricultural and marine products, several types of dryers are also being developed. However, they require a large amount of energy supplied conventionally from pollutant energy sources. The environmental concerns and depletion risks of fossil fuels persuade researchers and developers to seek alternative solutions. To perform drying applications, sustainable solar power may be effective because it is highly accessible in most regions of the world. Greenhouse dryers (GHDs) are simple facilities that can provide large capacities for drying agricultural products. This study reviews the integration of GHDs with different solar technologies, including photovoltaic (PV), photovoltaic-thermal (PVT), and solar thermal collectors. Additionally, the integration of solar-assisted greenhouse dryers (SGHDs) with heat pumps and thermal energy storage (TES) units, as well as their hybrid configuration considering integration with other renewable energy sources, is investigated to improve their thermal performance. In this regard, this review presents and discusses the most recent advances in this field. Additionally, the economic analysis of SGHDs is presented as a key factor to make these sustainable facilities commercially available.


2018 ◽  
Vol 35 (2) ◽  
pp. 197-203 ◽  
Author(s):  
Paweł Chmura ◽  
Marek Konefał ◽  
Jan Chmura ◽  
Edward Kowalczuk ◽  
Tomasz Zając ◽  
...  

2022 ◽  
pp. 1-32
Author(s):  
Hassan Salem ◽  
Ehab Mina ◽  
Raouf Abdelmessih ◽  
Tarek Mekhail

Abstract The cooling fluid is a key factor in cooling photovoltaic (PV) panels especially in the case of concentrated irradiance. Maintaining the panel at low temperature increases its efficiency. This paper investigates the usage of water-Al2O3 as a nanofluid for achieving the required cooling process. The particle concentrations and sizes are investigated to record their effect on heat transfer and pressure drop in the developing and developed regions. The research was performed using ANSYS CFD software with two different approaches: the single phase with average properties, and the discrete phase with the Eulerian-Lagrangian frame-work. Both approaches are compared to experimental results found in the literature. Both approaches show good agreement with the experimental results, with some advantage for the single-phase model both in processing time and in predicting heat transfer in the concentration range of 1-6% by volume. It was shown that, the heat transfer coefficient is greatly enhanced by increasing the particle concentration or decreasing the particle size. On the other hand, the usage of nanofluid causes a severe increase in the pumping power, especially with the increase in concentration and the reduction in particle size. Thus, a system optimization was suggested in order to raise the overall system efficiency for photovoltaic applications.


2019 ◽  
Vol 14 (8) ◽  
pp. 1050-1057 ◽  
Author(s):  
Alireza Rabbani ◽  
Mehdi Kargarfard ◽  
Carlo Castagna ◽  
Filipe Manuel Clemente ◽  
Craig Twist

Purpose: To investigate the relationship between accumulated global positioning system–accelerometer-based and heart rate–based training metrics and changes in high-intensity intermittent-running capacity during an in-season phase in professional soccer players. Methods: Eleven male professional players (mean [SD] age 27.2 [4.5] y) performed the 30-15 Intermittent Fitness Test (30-15IFT) before and after a 5-wk in-season training phase, and the final velocity (VIFT) was considered their high-intensity intermittent-running capacity. During all sessions, Edwards training impulse (Edwards TRIMP), Banister 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 0.70, [0.51–0.89]). Accumulated NBL, Banister TRIMP, and Edwards TRIMP showed large associations (r = .51–.54) with changes in VIFT. A very large relationship was also observed between accumulated Z5 TRIMP (r = .72) with changes in VIFT. Large to nearly perfect within-individual relationships were observed between NBL and some of the other training metrics (ie, Edwards TRIMP, Banister TRIMP, training duration, and total distance) in 10 out of 11 players. Conclusions: Heart rate–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 (ie, NBL) to track changes in high-intensity intermittent-running capacity of professional soccer players.


2019 ◽  
Vol 24 (4) ◽  
Author(s):  
Anderson Santiago Teixeira ◽  
Juliano Fernandes da Silva ◽  
Priscila Cristina dos Santos ◽  
Paulo Cesar do Nascimento Salvador ◽  
Fernando de Souza Campos ◽  
...  

Author(s):  
Paweł Chmura ◽  
Tomasz Podgórski ◽  
Marek Konefał ◽  
Andrzej Rokita ◽  
Jan Chmura ◽  
...  

The aim of this study was to determine relationships between repeated 1 × 1 small-sided games (SSGs) (variable duration, constant work-to-rest ratio) and the concentration of steroid hormones and characteristic fatigue markers in youth soccer players. Eighteen young male soccer players were assigned at random to two experimental groups: E1—undertaking a six 30 s one-on-one SSGs with a 2 min rest period; and E2—playing six 45 s SSGs with a 3 min rest interval. Capillary blood was collected from the players at rest, after the last game, and 15 and 30 min after the exercise protocol. The variables assessed included serum cortisol (C), free testosterone (FT) and total testosterone (TT). An effect was observed between the measurement times (TT (F = 15.26, p ≤ 0.0001), FT (F = 6.86, p = 0.0006)). In terms of cortisol (C) levels, no interactions or effect between the studied groups were revealed, but an interaction was found (F = 4.01, p = 0.0126) and the effect appeared between the measurement times (F = 11.16, p ≤ 0.0001). The study results show that in all likelihood, longer rest intervals in repeated 30 s 1 × 1 SSGs can reduce catabolic reactions and hence the risk of overtraining in youth soccer players.


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