Jose Ricardo Fernandez Alvarez - Academia.edu (original) (raw)
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Papers by Jose Ricardo Fernandez Alvarez
Journal of Strength and Conditioning Research, 2010
The purpose of this study was to examine the relationship between popular endurance field tests a... more The purpose of this study was to examine the relationship between popular endurance field tests and physical match performance in elite male youth soccer players. Eighteen male young soccer players (age 14.4±0.1 years, height 1.67±4.8 cm, body mass 53.6±1.8 kg) were randomly chosen among a population of elite-level soccer players. Players were observed during international championship games of the corresponding age categories and randomly submitted to the level 1 of the Yo-Yo intermittent recovery test (Yo-Yo IR1), the Multistage Fitness Test (MSFT) and the Hoff test on separate occasions. Physical and physiological match demands were assessed using Global Positioning System technology and short-range telemetry (GPS Elite, Canberra, Australia) respectively. Players covered 6087±582 m (5098-7019m) of which 15% (930±362 m; 442-1513) were performed at HIA. During the first and second half players attained 86.8±6.5 and 85.8±5.8% of HR max (p=0.17) with peak HR's of 100±2 and 99.4±3.2% of HR max, respectively. Players' Yo-Yo IR1 and MSFT performance were significantly related (r from 0.62 to 0.76) to a number of match physical activities. However the Hoff test was only significantly related with sprint distance (r=0.70, p=0.04). The Yo-Yo IR1 showed very large association with MSFT performance (r=0.89, p<0.0001). This study's results showed that Yo-Yo IR1 and MSFT test may be regarded as valuable tests to assess match fitness and subsequently guide training prescription in youth soccer players. The very large relationship between Yo-Yo IR1 and MSFT suggests their use according to 3 the period of the season and the aerobic-fitness level of the players. Due to the association of the Yo-Yo IR1 and MSFT with match physical performances these tests should be considered in talent selection and development.
A balance between forest production and protection is hard to achieve in arid zones due to their ... more A balance between forest production and protection is hard to achieve in arid zones due to their low potential for wood production. Prosopis flexuosa woodlands are the major woody formations in the Monte desert and are currently in a degraded state due to intense use. The main degradation factors in the study area are overgrazing and firewood extraction. We developed
Journal of Strength and Conditioning Research, 2010
The purpose of this study was to examine the relationship between popular endurance field tests a... more The purpose of this study was to examine the relationship between popular endurance field tests and physical match performance in elite male youth soccer players. Eighteen male young soccer players (age 14.4±0.1 years, height 1.67±4.8 cm, body mass 53.6±1.8 kg) were randomly chosen among a population of elite-level soccer players. Players were observed during international championship games of the corresponding age categories and randomly submitted to the level 1 of the Yo-Yo intermittent recovery test (Yo-Yo IR1), the Multistage Fitness Test (MSFT) and the Hoff test on separate occasions. Physical and physiological match demands were assessed using Global Positioning System technology and short-range telemetry (GPS Elite, Canberra, Australia) respectively. Players covered 6087±582 m (5098-7019m) of which 15% (930±362 m; 442-1513) were performed at HIA. During the first and second half players attained 86.8±6.5 and 85.8±5.8% of HR max (p=0.17) with peak HR's of 100±2 and 99.4±3.2% of HR max, respectively. Players' Yo-Yo IR1 and MSFT performance were significantly related (r from 0.62 to 0.76) to a number of match physical activities. However the Hoff test was only significantly related with sprint distance (r=0.70, p=0.04). The Yo-Yo IR1 showed very large association with MSFT performance (r=0.89, p<0.0001). This study's results showed that Yo-Yo IR1 and MSFT test may be regarded as valuable tests to assess match fitness and subsequently guide training prescription in youth soccer players. The very large relationship between Yo-Yo IR1 and MSFT suggests their use according to 3 the period of the season and the aerobic-fitness level of the players. Due to the association of the Yo-Yo IR1 and MSFT with match physical performances these tests should be considered in talent selection and development.
A balance between forest production and protection is hard to achieve in arid zones due to their ... more A balance between forest production and protection is hard to achieve in arid zones due to their low potential for wood production. Prosopis flexuosa woodlands are the major woody formations in the Monte desert and are currently in a degraded state due to intense use. The main degradation factors in the study area are overgrazing and firewood extraction. We developed