Anaerobic Threshold in Stand-up Paddle: Comparison Between Direct and Alternative Methods.

ABSTRACT: Balikian, P, Gomes de Araujo, G, Prado, ES, Ryan Geraldes, AA, Marinho de Lima, AH, and Mendes, EV. Anaerobic threshold in stand-up paddle: comparison between direct and alternative methods. J Strength Cond Res 36(7): 1896-1900, 2022-The purpose of this study was to test the validity of alternative protocols, mean velocity during 30 minutes of continuous effort (V30min) and critical velocity (CV), to estimate the anaerobic threshold in stand-up paddle (SUP). Eight athletes performed: 3 maximal efforts at 400-, 500-, and 800-m distances to determine CV values, using the distance-time relationship; 3 efforts at 85, 90, and 100% of maximal 500-m effort to determine the velocity related to 3.5 mmol·L-1 of lactate, assumed as the onset of blood lactate accumulation (OBLA) and; a 30-minute continuous effort to determine the V30min. All evaluations were separated by 48 hours, with the athletes using their own boards and paddles in the water. No differences were observed between the OBLA (2.35 ± 0.13 m·s-1) and alternative methods (CV: 2.42 ± 0.20 m·s-1; p = 0.10 and V30min: 2.32 ± 0.13 m·s-1; p = 0.63). Although strong correlations were observed between the OBLA and alternative methods (CV: r = 0.84 and V30min: r = 0.94), the limits of agreement were higher in CV (±0.23 m·s-1) than V30min (±0.08 m·s-1). These results demonstrate that both the CV and V30min are valid to estimate the OBLA. In view of the specificity of SUP and the high levels of agreement, the use of the V30min is recommended to prescribe training intensities.

Running sprint force-velocity-power profile obtained with a low-cost and low frame rate acquisition video technique: reliability and concurrent validity.

The Force-velocity (F-v) and Power-velocity (P-v) relationships quantify athlete's horizontal force production capacities during sprinting. Efforts are underway to enhance ecological validity for practitioners and sports coaches. This study provides detailed data comparison of a low frames per second setup (30 Hz; FPSlow) with splits from a high FPS camera to derive F-v and P-v relationships. Sixty-six sprints performed by 11 university track and field athletes (6 male, 5 female) were evaluated. Data were recorded using FPSlow, photocells, and a high-speed camera (240 Hz; MySprint). In the FPSlow setup, bias was 0.17s, and Limits of agreement was 0.09s compared to photocells. ICC was 1.00, and the coefficient of variation (CV) was 1.0% [0.8-1.1%]. Time acquisition comparison between MySprint and FPSlow setups revealed high consistency (ICC = 0.99) and low CV (2.9% [2.8-3.1%]). F-v profile variables exhibited biases from trivial to small, with ICC ranging from moderate to nearly perfect. CV ranged from 2.7% to 11.8%, and improved using the average of three sprints (CV between 1.8% and 8.6%). The 'simple method' applied to data from the low FPS video setup yielded kinetic and kinematic parameters comparable to those obtained by the validated previous method and photocells.

Acute metformin administration increases mean power and the early Power phase during a Wingate test in healthy male subjects.

The present study tested the hypothesis that acute metformin would increase peak power measured during a Wingate test. Fourteen men (24 ± 6 years; 75.8 ± 10.2 kg; 177 ± 7 cm) participated in four test sessions, conducted in a crossover, counterbalanced, double-blind model. The first and second sessions consisted of anthropometric measurements and one Wingate test per day to assess test-retest reliability. In the last two sessions, the Wingate tests were performed on metformin (500 mg capsule, 1 hour before) or placebo (cellulose capsule, 1 hour before) condition. No differences were found between the placebo and metformin for peak power (1056.8 ± 215.8 W vs. 1095.2 ± 199.3 W, respectively; p = 0.24). Mean power (630.9 ± 87.8 W vs. 613.1 ± 94.8 W, respectively; p=0.01) and total work (18928 ± 2633 kJ vs. 18393 ± 2845 kJ, respectively; p = 0.01) in the metformin condition were higher than the placebo. The power were greater in metformin when compared to the placebo in moments 3 (p = 0.01), 4 (p = 0.01), 5 (p = 0.04), 6 (p = 0.04), 7 (p = 0.02), 8 (p = 0.03) and 9 (p = 0.01) seconds. There were no differences between conditions for the peak lactate (p = 0.08) and the rating of perceived exertion (p = 0.84). Acute metformin administration increased the early power phase and the mean power of a Wingate test.

Validation of non-exhaustive test to determine the aerobic capacity in swimming.

BACKGROUND: Several methods of aerobic capacity evaluation have been applied to assess and prescribe the training sessions in swimming. However, most protocols either show exhaustive characteristics, triggering transitory stress period or several visits, influencing the session's organization. Thus, the purpose was to validate a double-bout exercise protocol for non-exhaustive aerobic capacity determination of swimmers. METHODS: Twelve swimmers were submitted to non-exhaustive and Maximal Lactate Steady State (MLSS) protocols. Non-exhaustive double effort test (NEDE) was performed into 4 sessions with randomized intensities 60-80 s/100 m. Sessions were divided in two bouts with same intensity, duration (180 s) and interval (90 s). Linear interpolation of heart rate difference (∆HR) and lactate difference (∆Lac) enabled determination of a "null" delta. NEDE and MLSS were performed for determination of reproducibility and validity respectively. RESULTS: The velocity (s/100 m) measured by Δ HR (test 75.16±0.84; retest 74.81±0.75) and ΔLac (test 75.08±0.87; retest 75.14±0.81) did not differ from MLSS (74.00±1.20). Significant correlation was found between test and retest for HR (P=0.001), Lac concentration (P=0.001) and MLSS (HR test P=0.0001; HR retest P=0.0001; Lac test P=0.002; Lac retest P=0.0001). CONCLUSIONS: In conclusion, non-exhaustive double test evaluated by ΔHR and ΔLac was reproducible and valid to determine the aerobic capacity in swimming.