Precision of 1-RM prediction equations in non-competitive subjects performing strength training

The purpose of this study was to assess the precision of the 1-RM prediction equations proposed by Adams (1994), Baechle and Groves (2000), Brzycki (1993), Epley (1985), Lander (1985) and O’Conner et al. (1989) for strength assessment in fitness programs. Thirty one healthy regular strength training male practitioners (mean ± SD: 21.8 ± 4.0 years of age; 75.9 ± 8.4 kg of weight; and 178.1 ± 6.4 cm of height) performed two tests on the bench press exercise: (a) maximum test - determination of the 1-RM load; and (b) submaximum test - determination of the load matching 4 to 10 maximum repetitions. Analysis of variance (ANOVA) found no significant difference (p > .05) between maximum load determination through prediction equations or through the 1-RM test. The coefficient of determination (r2) varied from .94 to .96. The prediction equations had small standard error of estimate (2.7 to 3.2 kg). Results indicate that the 1-RM prediction equations could be used to determine the maximum load at the bench press exercise in subjects with low strength training experience

Match internal load in youth elite soccer players is period, playing position and intermittent running capacity dependent

Aims: The aims of this study were: i) to verify whether player internal load (PIL) monitored via heart rate (HR) varies with game-time and playing position; ii) whether intermittent running capacity (IRC) is related to the maintenance of within-match PIL in elite youth (U-15) soccer players. Method: Twenty-one elite soccer players (14±0.5 yrs, 172±7 cm, 63±6 kg) had their heart rate monitored (beats/min) in five matches and were tested twice for IRC (Yo-YoIR2, distance [m]) over a seven-week competitive season. Percentage of maximal heart rate (%HRmax) and time spent (TS%) in five zones (Z1[96%]) were our PIL indexes. Data from three complete games in the same position of each player were analyzed and matches halves, time intervals (T1 to T6), and playing positions (fullbacks, central defenders and forwards [N=5 each], midfielders [N=6]) were compared, and the relationship between IRC and within-match PIL was determined. Results: PIL was higher in 1st (86±3%) than in the 2nd half (84±4%; p<.001). The 2nd half had more TS% in Z1 and Z2 (p<.05). PIL in T4 was the lowest (p<.01), and in T6, it was lower than T1 and T2 (p<.01). Fullbacks and midfielders showed higher PIL and higher TS% in Z4 (p<.05) than the other positional roles. The average IRC correlated with PIL in T6 (r=.56, p<.01) only. Conclusion: In conclusion, the internal load in elite youth (U-15) soccer players varies with game-time and playing position; and their IRC is related to the maintenance of within-match PIL