Systemic Lactate Elevation Induced by Tobacco Smoking during Rest and Exercise Is Not Associated with Nicotine.

Lactate is a metabolite produced during anaerobic glycolysis for ATP resynthesis, which accumulates during hypoxia and muscle contraction. Tobacco smoking significantly increases blood lactate. Here we conducted a counter-balanced crossover study to examine whether this effect is associated with inhaling nicotine or burned carbon particles. Fifteen male smokers (aged 23 to 26 years) were randomized into 3 inhalation conditions: tobacco smoking, nicotine vaping, and nicotine-free vaping, conducted two days apart. An electronic thermal evaporator (e-cigarette) was used for vaping. We have observed an increased blood lactate (+62%, main effect: p < 0.01) and a decreased blood glucose (−12%, main effect: p < 0.05) during thermal air inhalations regardless of the content delivered. Exercise-induced lactate accumulation and shuttle run performance were similar for the 3 inhalation conditions. Tobacco smoking slightly increased the resting heart rate above the two vaping conditions (p < 0.05), implicating the role of burned carbon particles on sympathetic stimulation, independent of nicotine and thermal air. The exercise response in the heart rate was similar for the 3 conditions. The results of the study suggest that acute hypoxia was induced by breathing thermal air. This may explain the reciprocal increases in lactate and decreases in glucose. The impaired lung function in oxygen delivery of tobacco smoking is unrelated to nicotine.

Características de lesões em paratletas da Indonésia antes das Olimpíadas de Tóquio em 2020: um estudo transversal / Injury characteristics of Indonesian paraathletes prior to Tokyo Olympics 2020: a crosssectional study

OBJETIVOS: Esta pesquisa tem como objetivo elucidar as características das lesões em atletas da seleção da Indonésia. MÉTODOS: Os sujeitos deste estudo foram nove atletas (masculino = 5, feminino = 4) com homens em torno da idade de 28 ± 9,13 e mulheres 28 ± 5,66 anos. A abordagem do método é descritiva com uma técnica de estudo transversal usando um questionário sobre histórico de lesões, tipos de lesões, fatores de lesões e gerenciamento de lesões para atletas indonésios que competiram nos Jogos Olímpicos de Tóquio em 2020. A análise de dados é representada em números e porcentagens e o teste exato de Fisher é usado para determinar a relação entre as variáveis. RESULTADOS: Os resultados do estudo relataram que os atletas indonésios sofreram lesões nos membros inferiores (70%), a parte do corpo que frequentemente sofre lesões foi a coxa (28%) e o tipo de lesão que frequentemente sofreu foi entorse / torção. CONCLUSÃO: As características da lesão na categoria sprint (pista) formam um padrão de lesões na coxa, tendão de Aquiles, tornozelo e joelho. Parece não haver correlação entre gênero, frequência de treinamento, proporção de lesões, número de partidas e tipo de aquecimento. A implicação é que o gerenciamento de lesões é necessário antes e durante a competição, considerando a biomecânica, a fisiopatologia e os problemas psicossociais. As estratégias de prevenção de lesões por treinadores e equipes médicas devem levar a uma redução mais significativa de lesões e otimizar a saúde, segurança e bem-estar dos atletas.

BACKGROUND: Sports for people with disabilities and injuries have been the subject of discourse in the professional literature in the fields of traumatology and sports medicine. OBJECTIVE: This research aims to elucidate the injury characteristics of athletes in the Indonesian national team. The subject of this study were nine athletes (male=5, female=4) with males around the age of 28±9.13 and females 28±5.66 years. METHOD: The method approach is descriptive with a crosssectional study technique using a questionnaire about injury history, types of injury, injury factors, and injury management for Indonesian Para Athletics Athletes who have competed in the 2020 Tokyo Olympics. Data analysis is depicted in numbers and percentages and Fisher's exact test is used to determine the relationship between variables. RESULTS: The study results reported that Indonesian athletes suffered injuries of the lower limbs (70%), part of the body that is frequently injured was the thigh (28%) and the type of injury that was often experienced sprain/twist. CONCLUSION: The injury characteristics in the sprint (track) category form a pattern of injuries to the thigh, Achilles tendon, ankle, and knee. There appears to be no correlation between gender, training frequency, injury share, match number, and warm-up type. The implication is that injury management is necessary before and during competition by considering biomechanics, pathophysiology, and psychosocial problems. Injury prevention strategies by coaches and medical teams should lead to more significant injury r

Influence of the Intention to Lean the Body Forward on Kinematics and Kinetics of Sprinting for Active Adults.

This study investigated the influence of the intention to lean the body forward on spatiotemporal and ground reaction force variables during the acceleration phase of a sprint. Fourteen active adults performed two 50 m sprints (with and without the intention to lean), during which spatiotemporal variables and impulses were obtained using a long force platform system. Effect size (Cohen's d) was used to examine the differences between the two trials. We found that running speed and net anteroposterior impulse did not change by the intention for all steps. However, step frequency increased in the initial two steps through decreases in support time and flight time by the intention. Moreover, these shorter support and flight times were caused by a decrease in the vertical impulse. The propulsive impulse did not change during the initial part of acceleration phase, but the braking impulse decreased at the first step. This study demonstrates that an intention to lean the body forward leads to a smaller braking impulse and a higher step frequency through shorter support and flight times and a smaller vertical impulse during the initial part of the acceleration phase of a sprint.

Cigarette Smoking Blunts Exercise-Induced Heart Rate Response among Young Adult Male Smokers.

This study aimed to examine the exercise-induced heart rate response (HRR) and heart rate variability (HRV) in subjects caused by inhaling smoke from tobacco cigarettes (TC) and aerosolized vapor from electronic nicotine dispensing systems (ENDS) (commonly referred to as e-cigarettes (EC)). A randomized crossover study recruited 24 young adult male smokers with an average age of 23 years and with a smoking habit of at least two years. Heart rate response was recorded after a maximal multistage shuttle 20 m run test (MMST) under three different levels of nicotine: Control 0 mg nicotine of EC (C), 3 mg nicotine of EC (3EC), and 3 mg nicotine of TC (3TC). HRV was evaluated based on the beat-to-beat time interval during the running test. The results showed no statistically significant differences in the run time to exhaustion under the three conditions (C: 398 ± 151 s; 3EC: 399 ± 160 s; 3TC: 381 ± 150 s). Exercise-induced HRR was significantly attenuated under the TC condition (p < 0.05). Intriguingly, the HRV standard deviation of normal-to-normal intervals (SDNN) during exercise significantly increased under 3EC and 3TC. The results showed that a significant acute autonomic cardiac modulation during exercise is induced by an acute episode of EC and TC smoking.