The aim of this study was to investigate the effects of fatigue induced by a field test representative of soccer specific movements on different hamstrings:quadriceps ratios in the dominant and non-dominant legs at two different velocities. Eight male football players (age: 21.3+/-2.3 years; height: 178+/-8 cm; body mass: 78+/-9 kg; playing level: British University Southern conference-3B) performed a pre-test to assess the concentric and eccentric strength of the hamstrings and the quadriceps at 60 degrees x s(-1) and 180 degrees x s(-1), The Loughborough Intermittent Shuttle Test (LIST) to simulate soccer, and a post-test similar to the pre-test. The main findings demonstrated significant decreases in the H(con):Q(con) ratio (calculated as the maximal concentric hamstrings strength divided by the maximal concentric quadriceps strength) in the dominant leg at 180 degrees x s(-1) and in the functional ratio H(ecc):Q(con) (calculated as the maximal eccentric hamstrings strength divided by the maximal concentric quadriceps strength) in the dominant leg at 60 degrees x s(-1) and 180 degrees x s(-1). In addition, significant correlations were observed between physiological parameters measured during the soccer-specific exercise and H(ecc):Q(con) only. These results suggested that the functional H(ecc):Q(con) ratio is more representative of fatigue induced by soccer than the conventional H(con):Q(con) ratio. Eccentric strength training at high velocities may be necessary to reduce injury risk in soccer players.

The purpose of this study was to investigate the effects of sodium bicarbonate (NaHCO(3)), caffeine, and their combination on repeated 200-m freestyle performance. Six elite male freestyle swimmers ingested NaHCO(3) (0.3 g/kg; B), caffeine (6.2 +/- 0.3 mg/kg; C), a combination of both (B+C), and placebo (P) on 4 separate occasions before completing 2 maximal 200-m freestyle time trials (TT1 and TT2) separated by 30 min. No significant differences (p = .06) were observed for performance in TT1 (B 2:03.01 +/- 0:03.68 min, C 2:02.42 +/- 0:03.17 min, B+C 2:01.69 +/- 0:03.19 min, P 2:03.77 +/- 0:03.21 min) or TT2 (B 2:02.62 +/- 0:04.16 min, C 2:03.90 +/- 0:03.58 min, B+C 2:01.70 +/- 0:02.84 min, P 2:04.22 +/- 0:03.75 min). The drop-off in performance time from TT1 to TT2, however, was significantly greater when C was ingested than with B (-1.5%, p = .002) or B+C (-1.2%, p = .024). This is likely because of the lower blood pH and slower recovery of blood HCO(3) post-TT1 after C ingestion. These findings suggest that the ergogenic benefit of taking C alone for repeated 200-m swimming performance appears limited. When combined with NaHCO(3), however, its negative impact on repeated maximal exercise performance is reversed.

Purpose: Several recent studies have reported substantial performance and physiological gains in well-trained endurance runners, swimmers, and cyclists following a period of high-intensity interval training (HIT). The aim of the current study was to compare traditional rowing training (CT) to HIT in well-trained rowers. Methods: Subjects included 5 male and 5 female rowers (mean ± SD; age = 19 ± 2 y; height = 176 ± 8 cm; mass = 73.7 ± 9.8 kg; Vo 2peak = 4.37 ± 1.08 L·min −1 ). Baseline testing included a 2000-m time trial and a maximal exercise test to determine Vo 2peak , 4-min all-out power, and 4 mmol·L −1 blood lactate threshold. Following baseline testing, rowers were randomly allocated to HIT or CT, which they performed seven times over a 4-wk period. The HIT involved 8  2.5-min intervals at 90% of the velocity maintained at Vo 2peak , with individual recoveries returning to 70% of the subjects' maximal heart rate between intervals. The CT intensity consisted of workloads corresponding to 2 and 3 mmol·L −1 blood lactate concentrations. On completion of HIT or CT, rowers repeated the testing performed at baseline and were then allocated to the alternative training program and completed a crossover trial. Results: HIT produced greater improvements in 2000-m time (1.9 ± 0.9%; mean ± SD), 2000-m power (5.8 ± 3.0%), and relative Vo 2peak (7.0 ± 6.4%) than CT. Conclusion: Four weeks of HIT improves 2000-m time-trial performance and relative Vo 2peak in competitive rowers, more than a traditional approach.

Background Higher cardiovascular health scores, using American Heart Association's (AHA) Life's Simple 7 (LS7), have been associated with lower risk of cardiovascular disease, type 2 diabetes, cancer, and mortality among all racial/ethnic groups. Nationally, Black men have the lowest levels of LS7. Thus, a study was conducted to evaluate the impact of a community-based team lifestyle change program on LS7 among Black men. Methods Black adult males ( n = 74) from a large Midwestern city participated in Black Impact, a 24-week community-based team lifestyle change program adapted from the Diabetes Prevention Program and AHA's Check, Change, Control Blood Pressure Self-Management Program, which incorporates AHA's LS7 framework. The change in a LS7 score (range 0–14) from baseline to 12 and 24 weeks was evaluated using a linear mixed-effects model adjusted for age, education, and income. Results The mean age of participants was 52 ± 10 years. The men were sociodemographically diverse, with annual income ranging from <$20,000 (7%) to ≥$75,000 (25%). Twenty-five percent were college graduates, 73% had private insurance, and 84% were employed. In fully adjusted models, LS7 score at baseline was 7.12 and increased 0.67 (95%CI: 0.14, 1.20, p = 0.013) and 0.93 (95%CI: 0.40, 1.46, p <0.001) points at 12 and 24 weeks, respectively, compared to baseline. Sensitivity analysis evaluating 5 components (excluding diet and physical activity) and 6 components (excluding diet) also showed significant increases at 12 and 24 weeks (all p <0.01). Conclusions The Black Impact lifestyle change single-arm pilot program showed that a community-based lifestyle intervention has the potential to improve LS7 in Black men. Further randomized studies are urgently needed to improve cardiovascular health and advance cardiovascular health equity in Black men.

The aims of this study were to document the effect terrain has on the physiological responses and work demands (power output) of riding a typical mountain bike cross-country course under race conditions. We were particularly interested in determining whether physiological measures relative to mass were better predictors of race performance than absolute measures. Eleven A-grade male cross-country mountain bike riders (VO2max 67.1 +/- 3.6 ml x kg(-1) x min(-1)) performed 2 tests: a laboratory-based maximum progressive exercise test, and a 15.5-km (six 2.58-km laps) mountain bike cross-country time trial. There were significant differences among the speed, cadence, and power output measured in each of 8 different terrain types found in the cross-country time trial course. The highest average speed was measured during the 10-15% downhill section (22.7 +/- 2.6 km x h(-1)), whereas the cadence was highest in the posttechnical flat sections (74.3 +/- 5.6 rpm) and lowest on the 15-20% downhill sections (6.4 +/- 12.1 rpm). The highest mean heart rate (HR) was obtained during the steepest (15-20% incline) section of the course (179 +/- 8 b x min(-1)), when the power output was greatest (419.8 +/- 39.7 W). However, HR remained elevated relative to power output in the downhill sections of the course. Physiological measures relative to total rider mass correlated more strongly to average course speed than did absolute measures (peak power relative to mass r = 0.93, p < 0.01, vs. peak power r = 0.64, p < 0.05; relative VO2max r = 0.80, p < 0.05, vs. VO2max r = 0.66, p < 0.05; power at anaerobic threshold relative to mass r = 0.78, p < 0.05, vs. power at anaerobic threshold r = 0.5, p < 0.05). This suggests that mountain bike cross-country training programs should focus upon improving relative physiological values rather than focusing upon maximizing absolute values to improve performance.