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.

Different dehydration levels and their impact on blood ammonia, cognitive-motor performance, and muscle damage in acclimated runners.

BACKGROUND: Prolonged exercise in the heat can promote dehydration, which could impair ammonia metabolism, cognitive-motor performance, and muscle damage. However, exercise heat acclimation induces physiological adaptations that improve performance, metabolism, and cellular protection. This study aimed to evaluate different dehydration levels and their impact on blood ammonia, cognitive-motor performance, and muscle damage after a race in the heat in acclimated runners. METHODS: Sixteen male amateur endurance runners performed a half marathon race. After the race, the runners were divided into two groups according to their percentage body mass change (Δ% BM): Δ% BM less than 3% (G1%; N.=8) and Δ% BM greater than or equal to 3% (G3%; N.=8). Hydration status, biochemical parameters, and cognitive-motor performance were assessed before and after the race. RESULTS: Blood ammonia concentrations were increased in both G1% (before: 46±26 µmol/L; after: 118±22 µmol/L) and G3% (before: 41±15 µmol/L; after: 108±15 µmol/L) groups. There was an early increase in all markers of muscle damage (creatine kinase [CK], lactate dehydrogenase [LDH], aspartate aminotransferase [AST], and alanine aminotransferase [ALT]) in both groups, but only LDH was greater in the G3% group than in the G1% group. Cognitive-motor performance did not differ between groups. CONCLUSIONS: Dehydration up to ~4% BM loss does not affect blood ammonia concentrations and cognitive-motor performance in acclimated runners. The results also suggest that exercising in the heat induces the early appearance of several markers of muscle damage in acclimated runners regardless of hydration status.

Physiological and technical demands of the small-sided and generic games in female futsal players

Abstract Aim: This study aimed to compare the heart rate (HR) values and technical actions frequencies during small-sided (SSG) and generic (GG) games in women futsal players. Methods: Six futsal players (age: 20.5 ± 7.4 years, height: 163.3 ± 16 cm, body mass: 57.9 ± 22 kg, maximum rate of oxygen consumption (VO2max): 42.0 ± 9 mL.kg.min−1) performed two experimental conditions in two days separated for at least 72h of interval: (1) one set of 10 min of SSG, 3x3 players; and (2) one set of 10 min of GG, 4 (1 joker) x 4 (1 joker) players. During each experimental session, the subject's HR values were monitored every 1 min of play. Pass, shot, dribbling, driving, and disarmament were recorded during the games. Results: There was no difference between SSG and GG for HR average (p = 0.50). The HR values that were recorded at the first minute of GG were higher than SSG (p = 0.02). The HRmax in SSG and GG were equivalent to 91.9% and 90.8% of HRmax of the incremental test, respectively. Total technical actions were higher in SSG (+ 18.4%, p = 0.001) than GG. Pass was higher in the SSG (+16%; p = 0.01) in comparison to GG. Conclusion: Both models were higher than HRmax equivalent to AT velocity. The technical actions of the SSG were higher than GG, suggesting that the SSG model is a suitable technical and physiological stimulus for the development of female futsal players.

Salivary total protein as a biomarker of anaerobic threshold in elderly athletes subjected to an incremental physical test.

This study aimed to verify whether salivary total protein (STP) would reflect anaerobic threshold in elderly athletes subjected to an incremental exercise test. METHODS: Seven elderly elite athletes (EEA) and six physically active elderly men (PAE) completed a treadmill protocol in which blood and saliva samples were collected. RESULTS: Blood lactate (BL) and STP increased significantly in EEA during the test (0.8 ± 0.2 to 5.1 ± 2.0 mmol/L and 42.5 ± 7.5 to 222.5 ± 63.8 mg/dL, respectively) and remained elevated at five minutes after exercise (5.0 ± 1.9 mmol/L and 147.2 ± 50.0 mg/dL, respectively). Furthermore, correlations between STP and heart rate (r = 0.87, p < 0.001), and between BL and STP (r = 0.96, p < 0.001), were observed in the elderly athletes. CONCLUSIONS: STP represents a potential non-invasive biomarker for determining anaerobic threshold during an incremental exercise test, and this parameter may be used as an indicator of physical exercise intensity in elderly athletes.

Keto analogues and amino acid supplementation and its effects on ammonaemia during extenuating endurance exercise in ketogenic diet-fed rats.

Keto analogues and amino acids (KAAA) supplementation can reduce blood ammonia concentrations in athletes undergoing high-intensity exercise under both ketogenic and thermoneutral conditions. This study evaluated the acute effects of KAAA supplementation on ammonia metabolism during extenuating endurance exercise in rats fed a ketogenic diet. In all, eighty male Fischer rats at 90 d of age were divided into eight groups, and some were trained using a swimming endurance protocol. A ketogenic diet supplemented with keto analogues was administered for 10 d. Administration of the ketogenic diet ended 3 d before the exhaustion test (extenuating endurance exercise). A ketogenic diet plus KAAA supplementation and extenuating endurance exercise (trained ketogenic diet supplemented with KAAA (TKKa)) increased blood ammonia concentrations by approximately 50 % compared with the control diet (trained control diet supplemented with KAAA (TCKa)) and similar training (effect size=1·33; statistical power=0·50). The KAAA supplementation reduced blood urea concentrations by 4 and 18 % in the control and ketogenic diet groups, respectively, compared with the groups fed the same diets without supplementation. The trained groups had 60 % lower blood urate concentrations after TCKa treatment than after TKKa treatment. Our results suggest that KAAA supplementation can reduce blood ammonia concentrations after extenuating endurance exercise in rats fed a balanced diet but not in rats fed a ketogenic diet.