Emerson Filipino Coelho

Pulmonary Oxygen Uptake Kinetics During Exercise in Subclinical Hypothyroidism

BACKGROUND Patients with subclinical hypothyroidism (SCH) have lower exercise tolerance, but the impact on oxygen uptake (VO2) kinetics is unknown. This study evaluated VO2 kinetics during and after a constant load submaximal exercise in SCH. METHODS The study included 19 women with SCH (thyrotropin (TSH)=6.87±2.88 μIU/mL, free thyroxine (fT4)=0.97±0.15 ng/dL) and 19 controls (TSH=2.29±0.86 μIU/mL, T4=0.99±0.11 ng/dL) aged between 20 and 55 years. Ergospirometry exercise testing was performed for six minutes with a constant load of 50 W, followed by six minutes of passive recovery. The VO2 kinetics was quantified by the mean response time (MRT), which is the exponential time constant and approximates the time needed to reach 63% of change in VO2 (ΔVO2). The O2 deficit-energy supplied by anaerobic metabolism at the onset of exercise-and O2 debit-extra energy demand during the recovery period-were calculated by the formula MRT×ΔVO2. Values are mean±standard deviation. RESULTS In the rest-exercise transition, patients with SCH showed slower VO2 kinetics (MRT=47±8 sec vs. 40±6 sec, p=0.004) and a higher oxygen deficit (580±102 mL vs. 477±95 mL, p=0.003) than controls respectively. In the exercise-recovery transition, patients with SCH also showed slower VO2 kinetics (MRT=54±6 sec vs. 44±6 sec, p=0.001) and a higher oxygen debit (679±105 mL vs. 572±104 mL, p=0.003). The VO2 kinetics showed a significant correlation with TSH (p<0.05). CONCLUSIONS This study demonstrates that women with SCH have the slowest VO2 kinetics in the onset and recovery of a constant-load submaximal exercise and highlights that this impairment is already manifest in the early stage of the disease.

Oxygen Uptake and Heart Rate Kinetics after Different Types of Resistance Exercise

Abstract Oxygen uptake (VO2) and heart rate (HR) kinetics after exercise are important indicators of fitness and cardiovascular health. However, these variables have been little investigated in resistance exercise (RE). The current study compared post-exercise kinetics of VO2 and the HR among different types of REs. The study included 14 males (age: 26.5±5.4 years, body mass: 80.1±11.4 kg, body height: 1.77±0.07 m, fat content: 11.3±4.6%) with RE experience. Dynamic muscle strength was measured using one repetition maximum (1RM) with regard to the half-squat, bench press, pull-down, and triceps pushdown exercises. The participants performed a maximum number of repetitions at 80% of 1RM for each exercise, separated by a recovery period of 60 minutes. VO2 was measured using ergospirometry. VO2 and HR kinetics were assessed using the time constant of the recovery curves, and excess oxygen consumption (EPOC) was calculated afterward. Significant differences were not observed across the exercises with regard to VO2 kinetics. However, the half-squat exercise elicited a greater EPOC than the bench press and triceps pushdown exercises (p<.05). HR kinetics was slower for the half-squat exercise than for the other exercises (p<.05). These findings confirm that the type of RE influences both the cardiac autonomic response post-exercise and EPOC, but not VO2 kinetics

Relative age effect on olympic triathlon athletes

INTRODUCAO: Nas competicoes esportivas disputadas por categorias de idade, acredita-se que jovens nascidos nos primeiros meses do ano tenham vantagens, por serem alguns meses mais maduros do que seus pares. Esta diferenca na idade relativa pode influenciar a selecao dos atletas pelos treinadores. Este fenomeno, comumente estudado em esportes coletivos, tem sido pouco investigado em esportes individuais.OBJETIVO: O presente estudo analisou o trimestre de nascimento dos atletas olimpicos de triatlo de ambos os sexos que participaram das Olimpiadas de Londres 2012.METODOS: Foi identificado o quartil (trimestre) de nascimento de 111 atletas (55 homens e 56 mulheres). Para a analise dos dados, empregou-se o teste qui-quadrado com nivel de significância de 5%.RESULTADOS: Nos homens, foi observada uma maior predominância de atletas nascidos no primeiro e segundo quartis (X2 = 11,545; gl= 3; p=0,01), enquanto que nas mulheres esta tendencia nao foi observada (X2=1,286; gl=3; p=0,73). Verificou-se ainda relacao significativa entre o semestre de nascimento e a conquista de medalhas.CONCLUSAO: O efeito da idade relativa foi observado nos triatletas das Olimpiadas de Londres 2012 do sexo masculino, sendo relacionado ao desempenho dos atletas. Isto sugere que a data de nascimento pode ter influenciado a selecao desses atletas nas etapas de formacao. Novos estudos ainda sao necessarios para confirmar o fenomeno da idade relativa no triatlo.ABSTRACT Introduction: In sports contested by age categories, it is believed that young people born in the first months of the year show advantages because they are a few months more mature than their peers. This difference in relative age may influence the selection of athletes by coaches. This phenomenon, commonly studied in team sports, has been little studied in individual sports. Objective: The present study examined the quarter of birth date of triathlon Olympic athletes of both genders, who participated in the London Olympics 2012. Methods: The quartile (quarter) of birth date of 111 athletes (55 men and 56 women) was identified. For data analysis, the chi-square test with a significance level of 5% was employed. Results: In men, there was a predominance of athletes born in the first and second quartiles (X 2 = 11,545; gl = 3; p=0,01), whereas in women this trend was not observed (X 2 = 1,286; gl = 3; p=0,73). There was also a significant relationship between the semester of birth and winning medals. Conclusion: We concluded that the relative age effect was observed in triathletes on the London Olympics 2012 and it is related to performance in men. This suggests that the birth date may have influenced the selection of these athletes in the formative years. Further studies are needed to confirm the relative age effect in triathlon.Keywords: athletes/classification, athletes/statistics & numerical data, age distribution.

The relative age effect in olympic swimmers

O objetivo foi investigar o efeito da idade relativa (EIR) em nadadores nos Jogos Olimpicos de 2012, analisando as diferencas entre os continentes, sexos e a relacao com a conquista ou nao de medalhas. Novecentos e setenta e oito atletas (507 homens e 471 mulheres) foram estratificados a partir do seu quartil de nascimento. Na distribuicao dos quartis, foi observado um maior percentual de atletas nascidos no 1o e 3o quartil. Ja na distribuicao por sexo, o EIR foi verificado para feminino (χ2 = 12.304; gl = 3; p = .01), mas nao para o masculino (χ2 = 1.426; gl = 3; p = .70). Quanto a analise do efeito da idade relativa pelo desempenho e por continente, nao houve relacao significativa entre o quartil de nascimento e a conquista de medalha e o continente asiatico foi o unico em que foi verificado o efeito da idade relativa, respectivamente. Concluiu-se que o efeito da idade relativa esta presente em nadadores de Londres 2012. Alem disso foi representativo em relacao as mulheres, nao esta relacionado a conquista de medalhas olimpicas e esta presente apenas no continente asiatico.

Heart rate kinetics during exercise in patients with subclinical hypothyroidism

Studies suggest that patients with subclinical hypothyroidism (SH) have sympathovagal imbalance, which could lead to a slower heart rate (HR) response in the transition from rest to exercise. Thus the objective of this study was to investigate the behavior of the HR kinetics in patients with SH during the transition from rest to exercise. The study included 18 SH women [thyroid stimulating hormone (TSH) = 6.95 ± 2.94 μIU/ml and free thyroxine (FT4) = 0.96 ± 0.15 ng/dl] and 17 euthyroid women (TSH = 2.28 ± 0.84 μIU/ml and FT4 = 0.98 ± 0.07 ng/dl). Both groups were matched for physical activity, menopausal status, and age. The HR kinetics was obtained during the course of a constant-load exercise (50 W), for 6 min, in a cycle ergometer, and quantified from the mean response time (MRT), which is equivalent to the time taken to reach 63% of the HR at steady state. SH patients showed slower HR kinetics than the control group (MRT = 48.5 ± 17.6 vs. 36.0 ± 10.3 s, P = 0.015). The MRT has been shown to correlate with the level of physical activity (r = -0.361; P = 0.033) and with the subjective perception of exertion at the end of the exercise (r = 0.365; P = 0.031). It is concluded that SH patients have slower HR kinetics in the transition from rest to exercise compared with euthyroid women, with this impairment being associated with lower levels of physical activity.NEW & NOTEWORTHY Subclinical hypothyroidism patients have slower heart rate kinetics in the transition from rest to exercise when performing a constant-load exercise at 50 W.

Efecto de la edad relativa en atletas olímpicos de triatlón

INTRODUCAO: Nas competicoes esportivas disputadas por categorias de idade, acredita-se que jovens nascidos nos primeiros meses do ano tenham vantagens, por serem alguns meses mais maduros do que seus pares. Esta diferenca na idade relativa pode influenciar a selecao dos atletas pelos treinadores. Este fenomeno, comumente estudado em esportes coletivos, tem sido pouco investigado em esportes individuais.OBJETIVO: O presente estudo analisou o trimestre de nascimento dos atletas olimpicos de triatlo de ambos os sexos que participaram das Olimpiadas de Londres 2012.METODOS: Foi identificado o quartil (trimestre) de nascimento de 111 atletas (55 homens e 56 mulheres). Para a analise dos dados, empregou-se o teste qui-quadrado com nivel de significância de 5%.RESULTADOS: Nos homens, foi observada uma maior predominância de atletas nascidos no primeiro e segundo quartis (X2 = 11,545; gl= 3; p=0,01), enquanto que nas mulheres esta tendencia nao foi observada (X2=1,286; gl=3; p=0,73). Verificou-se ainda relacao significativa entre o semestre de nascimento e a conquista de medalhas.CONCLUSAO: O efeito da idade relativa foi observado nos triatletas das Olimpiadas de Londres 2012 do sexo masculino, sendo relacionado ao desempenho dos atletas. Isto sugere que a data de nascimento pode ter influenciado a selecao desses atletas nas etapas de formacao. Novos estudos ainda sao necessarios para confirmar o fenomeno da idade relativa no triatlo.ABSTRACT Introduction: In sports contested by age categories, it is believed that young people born in the first months of the year show advantages because they are a few months more mature than their peers. This difference in relative age may influence the selection of athletes by coaches. This phenomenon, commonly studied in team sports, has been little studied in individual sports. Objective: The present study examined the quarter of birth date of triathlon Olympic athletes of both genders, who participated in the London Olympics 2012. Methods: The quartile (quarter) of birth date of 111 athletes (55 men and 56 women) was identified. For data analysis, the chi-square test with a significance level of 5% was employed. Results: In men, there was a predominance of athletes born in the first and second quartiles (X 2 = 11,545; gl = 3; p=0,01), whereas in women this trend was not observed (X 2 = 1,286; gl = 3; p=0,73). There was also a significant relationship between the semester of birth and winning medals. Conclusion: We concluded that the relative age effect was observed in triathletes on the London Olympics 2012 and it is related to performance in men. This suggests that the birth date may have influenced the selection of these athletes in the formative years. Further studies are needed to confirm the relative age effect in triathlon.Keywords: athletes/classification, athletes/statistics & numerical data, age distribution.

Efeito da idade relativa em atletas olímpicos de triatlo

INTRODUCAO: Nas competicoes esportivas disputadas por categorias de idade, acredita-se que jovens nascidos nos primeiros meses do ano tenham vantagens, por serem alguns meses mais maduros do que seus pares. Esta diferenca na idade relativa pode influenciar a selecao dos atletas pelos treinadores. Este fenomeno, comumente estudado em esportes coletivos, tem sido pouco investigado em esportes individuais.OBJETIVO: O presente estudo analisou o trimestre de nascimento dos atletas olimpicos de triatlo de ambos os sexos que participaram das Olimpiadas de Londres 2012.METODOS: Foi identificado o quartil (trimestre) de nascimento de 111 atletas (55 homens e 56 mulheres). Para a analise dos dados, empregou-se o teste qui-quadrado com nivel de significância de 5%.RESULTADOS: Nos homens, foi observada uma maior predominância de atletas nascidos no primeiro e segundo quartis (X2 = 11,545; gl= 3; p=0,01), enquanto que nas mulheres esta tendencia nao foi observada (X2=1,286; gl=3; p=0,73). Verificou-se ainda relacao significativa entre o semestre de nascimento e a conquista de medalhas.CONCLUSAO: O efeito da idade relativa foi observado nos triatletas das Olimpiadas de Londres 2012 do sexo masculino, sendo relacionado ao desempenho dos atletas. Isto sugere que a data de nascimento pode ter influenciado a selecao desses atletas nas etapas de formacao. Novos estudos ainda sao necessarios para confirmar o fenomeno da idade relativa no triatlo.ABSTRACT Introduction: In sports contested by age categories, it is believed that young people born in the first months of the year show advantages because they are a few months more mature than their peers. This difference in relative age may influence the selection of athletes by coaches. This phenomenon, commonly studied in team sports, has been little studied in individual sports. Objective: The present study examined the quarter of birth date of triathlon Olympic athletes of both genders, who participated in the London Olympics 2012. Methods: The quartile (quarter) of birth date of 111 athletes (55 men and 56 women) was identified. For data analysis, the chi-square test with a significance level of 5% was employed. Results: In men, there was a predominance of athletes born in the first and second quartiles (X 2 = 11,545; gl = 3; p=0,01), whereas in women this trend was not observed (X 2 = 1,286; gl = 3; p=0,73). There was also a significant relationship between the semester of birth and winning medals. Conclusion: We concluded that the relative age effect was observed in triathletes on the London Olympics 2012 and it is related to performance in men. This suggests that the birth date may have influenced the selection of these athletes in the formative years. Further studies are needed to confirm the relative age effect in triathlon.Keywords: athletes/classification, athletes/statistics & numerical data, age distribution.

Prejuízo da vasodilatação muscular durante estresse mental em mulheres com hipotireoidismo subclínico

Objective To test the hypothesis that women with subclinical hypothyroidism (SH) have forearm vascular conductance (FVC) impaired during mental stress. Subjects and methods We evaluated 20 women with SH and 21 euthyroid (Control group), matched for age (p = 0.699) and body mass index (p = 0.462). Muscle blood flow (MBF) was assessed by venous occlusion plethysmography and blood pressure by Dixtal2023. Both variables were recorded simultaneously for 3 minutes of baseline followed by 3 minutes of mental stress. The FVC was calculated by dividing MBF by mean arterial pressure. Significant differences were assumed at p < 0.05. Results The SH group had higher concentrations of thyroid stimulating hormone (7.57 ± 3.17 vs. 2.10 ± 0,88 mU/L, p < 0.001). At baseline, the SH and control groups were similar for MBF (2.50 ± 0.79 vs. 2.55 ± 0,71 mL/ min/100 mL, p = 0.905, respectively) and FVC (2.80 ± 0.90 vs. 2.92 ± 0.88 units, p = 0.952, respectively). Throughout the mental stress test the SH and Control groups increased the MBF (time effect, p < 0.001) and FVC (time effect, p < 0.001) compared to baseline protocol. However, these variables were lower in SH group during the first (MBF: 3.66 ± 0.96 vs. 4.66 ± 1,61 mL/min/100 mL, p = 0.018, FVC: 3.95 ± 1.08 vs. 5.19 ± 1,96 units, p = 0.010) and second (MBF: 3.55 ± 1.01 vs. 4.62 ± 2,27 mL/min/100 ml, p = 0.018; FVC: 3.75 ± 1.07 vs. 4.92 ± 2,37 units, p = 0.020) minutes of mental stress test. Conclusion Women with SH have reduced muscle vasodilatatory response during mental stress.