New Predictive Resting Metabolic Rate Equations for High-Level Athletes: A Cross-Validation Study.

PURPOSE: The present study aims a) to assess the agreement between the measured resting metabolic rate (RMR) using indirect calorimetry and different predictive equations (predicted RMR), and b) to propose and cross-validate two new predictive equations for estimating the RMR in high-level athletes. METHODS: The RMR of 102 athletes (44 women) was assessed using indirect calorimetry, whereas the body composition was assessed using skinfolds. Comparisons between measured and predicted RMR values were performed using one-way ANOVA. Mean difference, root mean square error (RMSE), simple linear regression, and Bland-Altman plots were used to evaluate the agreement between measured and predicted RMR. The accuracy of predictive equations was analyzed using narrower and wider accuracy limits (±5% and ±10%, respectively) of measured RMR. Multiple linear regression models were employed to develop the new predictive equations based on traditional predictors (equation 1) and the stepwise method (equation 2). RESULTS: The new equations 1 and 2 presented good agreement based on the mean difference (3 and -15 kcal·d -1 ), RMSE (200 and 192 kcal·d -1 ), and R2 (0.71 and 0.74), respectively, and accuracy (61% of subjects between the limit of ±10% of measured RMR). Cunningham's equation provided the best performance for males and females among the existing equations, whereas Jagim's equation showed the worst performance for males (mean difference = -335 kcal·d -1 ; RMSE = 386 kcal·d -1 ). Compared with measured RMR, most predictive equations showed heteroscedastic distribution (linear regression's intercept and slope significantly different from zero; P ≤ 0.05), mainly in males. CONCLUSIONS: The new proposed equations can estimate the RMR in high-level athletes accurately. Cunningham's equation is a good option from existing equations, and Jagim's equation should not be used in high-level male athletes.

Maximal and Submaximal Cardiorespiratory Responses to a Novel Graded Karate Test.

The present study aimed to propose and assess the physiological responses of a novel graded karate test. Ten male national-level karate athletes (age 26 ± 5 yrs; body mass 69.5 ± 11.6 kg; height 1.70 ± 0.09 m) performed two exercise tests (separated by 2-7 days): 1) a running-based cardiopulmonary exercise test; 2) a graded karate test. The cardiopulmonary exercise test was comprised of an individualized ramp protocol for treadmill running, and the graded karate test was comprised of a sequence of 'kisami-gyaku-zuki" punching at a fixed frequency of a stationary target that becomes progressively distant. Cardiorespiratory responses, blood lactate concentration, and perceived exertion were measured. A verification phase was also performed in both tests to confirm the maximal physiological outcomes. The graded karate test evoked similar maximal responses to the running protocol: V̇O2 (57.4 ± 5.1 vs 58.3 ± 3.5 mL·kg-1·min-1; p = 0.53), heart rate (192 ± 6 vs 193 ± 10]beats.min-1; p = 0.62) and blood lactate (14.6 ± 3.4 vs 13.1 ± 3.0 mmol·L-1; p = 0.14) with a shorter duration (351 ± 71 vs 640 ± 9 s; p < 0.001). Additionally, the graded karate test evoked higher V̇O2 (72.6 ± 6.5 vs 64.4 ± 4.3 %V̇O2MAX; p = 0.005) and heart rate (89.4 ± 4.6 vs 77.3 ± 7.2 %HRMAX p < 0.001) at the ventilatory threshold and a higher heart rate (97.0 ± 2.4 vs 92.9 ± 2.2 %HRMAX; p = 0.02) at the respiratory compensation point. Incremental and verification phases evoked similar responses in V̇O2 and minute-ventilation during both tests. This novel displacement-based sport-specific test evoked similar maximal and higher submaximal responses, indicating a superior pathway to assess karate athletes.

Especificidade da atividade mioelétrica no agachamento excêntrico declinado em 25º e no agachamento padrão com diferentes sobrecargas / Specificity of the myoelectrical activity on the eccentric decline squat at 25º and standard squat with different overloads

OBJETIVO: O objetivo neste estudo foi comparar a atividade mioelétrica entre o agachamento unilateral declinado e o agachamento unilateral em superfície plana, no deslocamento vertical de duas diferentes quantidades de massa. PARTICIPANTES: Um grupo de oito sujeitos treinados recreacionalmente sem sinais e sintomas de lesões nas extremidades inferiores. PROCEDIMENTOS: Em dias separados, os sujeitos realizaram dois tipos distintos de agachamento unilateral na fase descendente, diferenciados em função da direção da base de sustentação, sendo uma horizontal e outra inclinada a 25º. Os dois tipos de agachamento foram realizados com dois valores de carga, com o peso do próprio corpo e com sobrecarga representativa de 15 repetições máximas (15RM). MENSURAÇÕES: As atividades mioelétricas do reto femoral, vasto lateral, posteriores de coxa mediais (semimembranoso e semitendinoso) e gastrocnêmio medial foram mensuradas nas quatro situações de teste. RESULTADOS: O grupamento muscular quadríceps mostrou-se sensível à magnitude do ângulo de inclinação da plataforma, manifestando maior atividade no agachamento declinado, e não apresentou aumentos na ativação muscular como resposta ao aumento da carga. Os músculos mediais posteriores da coxa e o gastrocnêmio medial não se mostraram sensíveis à angulação da plataforma nem ao aumento da sobrecarga. Apesar das taxas de co-contração não serem semelhantes entre as quatro situações testadas, as diferenças entre elas não se mostraram estatisticamente significativas. CONCLUSÃO: Os resultados confirmaram a maior ativação do quadríceps gerada no agachamento declinado em comparação ao agachamento realizado em superfície plana, sugerindo que esse exercício pode constituir uma alternativa para programas de reabilitação da tendinopatia patelar. Apesar de não termos encontrado diferenças estatisticamente significativas em relação à co-contração muscular, os achados sugerem que esse exercício deve ser utilizado com...

OBJECTIVE: The aim of this study was to compare the myoelectrical activity between the single-leg decline squat and the single-leg standard squat, with two different overloads. PARTICIPANTS: A group of eight recreationally trained subjects with no signs or symptoms of injury in the lower limb. PROCEDURES: On different days, the subjects performed two distinct kinds of unilateral eccentric squat, differentiated by the direction of the base of support, being one flat and the other declined at 25º. These two squats were carried out with two different overloads: with no extra overload and with an overload that represented 15 maximum repetitions (RM). OUTCOME MEASURES: The myoelectrical activities of the rectus femoris, vastus lateralis, medial hamstrings and gastrocnemius medialis were measured in the four test conditions (Flat and Decline Squat with and without extra overload). RESULTS: The quadriceps muscles were sensitive to the platform angle, showing greater activity on the decline squat; however, they did not show increase in the activation when overload was added. The medial hamstrings and gastrocnemius medialis were not sensitive to the platform angle or to the overload increase. In spite of the alterations in the muscular co-contraction ratio in several situations, we did not find any statistically significant differences among the four conditions tested. CONCLUSION: The results confirmed the higher activation of quadriceps generated in the decline squat compared to the standard squat, suggesting that this exercise is an interesting choice for rehabilitation management of patellar tendinopathy. Despite the non-significant statistical differences regarding muscular co-contraction, this exercise should be used with caution, since muscle synergism is changed as a function of tested variables, altering the specificity of this exercise in relation to sports activities, mainly in the coordination aspect.