The aim of this study was to explore the effects of static and dynamic stretching of the leg flexors and extensors on concentric and eccentric peak torque (PT) and electromyography (EMG) amplitude of the leg extensors and flexors in women athletes. Ten elite women athletes completed the following intervention protocol in a randomized order on separate days: (a) non-stretching (control), (b) static stretching, and (c) dynamic stretching. Stretched muscles were the quadriceps and hamstring muscles. Before and after the stretching or control intervention, concentric and eccentric isokinetic PT and EMG activity of the leg extensors and flexors were measured at 60 and 180 degrees/s. Concentric and eccentric quadriceps and hamstring muscle strength at both test speeds displayed a significant decrease following static stretching (P<0.01-0.001). In contrast, a significant increase was observed after dynamic stretching for these strength parameters (P<0.05-0.001). Parallel to this, normalized EMG amplitude parameters exhibited significant decreases following static (P<0.05-0.001) and significant increases following dynamic stretching (P<0.05-0.001) during quadriceps and hamstring muscle actions at both concentric and eccentric testing modes. Our findings suggest that dynamic stretching, as opposed to static or no stretching, may be an effective technique for enhancing muscle performance during the pre-competition warm-up routine in elite women athletes.

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Background Pain has been frequently described as a clinical feature of COVID‐19, and the main pain syndromes that have been associated with the acute phase of this disease so far are headache, myalgia, arthralgia, and neuropathic pain. Understanding the characteristics of pain symptoms is crucial for a better clinical approach. Methods Patients who were diagnosed as having COVID‐19 using reverse transcription‐polymerase chain reaction were included in the study. Patients were asked to complete a 51‐item questionnaire via a phone interview, which included questions on demographics, acute COVID‐19 symptoms, the presence of pain symptoms, and their characteristics in the acute phase of COVID‐19. Results A total of 222 out of 266 patients with COVID‐19 participated in the study, yielding a response rate of 83.5%. A total of 159 patients reported at least one kind of pain syndrome with a prevalence of 71.6%. Myalgia was reported in 110 (49.6%) patients, headache in 109 (49.1%), neuropathic pain symptoms in 55 (24.8%), and polyarthralgia in 30 (13.5%) patients. A total of 66 patients reported only one type of pain, 46 reported two types, 42 reported three types, and five patients reported all four types of pain. Logistic regression analysis showed that there were significant associations between these pain syndromes and a strong association was found between neuropathic pain and headache. Conclusion Pain is a frequently observed symptom of mild‐to‐moderate COVID‐19. There are significant relationships between pain syndromes in COVID‐19, which may be due to a sequence of common etiologic factors. Significance This study described the main pain syndromes associated acute phase of mild‐to‐moderate COVID‐19 and its associated features. Headaches and pain of neuropathic characteristics were prevalent in this sample.

The purpose of this study was to investigate the individual and combined antioxidant effects of menstrual cycle phase-related alterations in blood serum oestradiol concentrations and of dietary vitamin E supplementation on exercise-induced oxidative stress and muscle performance. A group of 18 sedentary women, aged 19-35 years, were given supplements of 300 mg alpha-tocopherol (n = 10) or placebo (n = 8) daily during the course of two menstrual cycles. The subjects exercised the knee isokinetically to exhaustion after cycling submaximally at 50% maximal oxygen uptake during the menstrual and preovulatory phases of their menstrual cycles. Blood samples were taken before and after the exercise, to evaluate haematocrit, plasma lactic acid and malondialdehyde concentrations, erythrocyte antioxidant enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx) activities and apolipoprotein B containing lipoprotein (non-high density lipoprotein, HDL, fraction) oxidation. Serum vitamin E, follicle stimulating hormone, luteinizing hormone and oestradiol concentrations were measured in pre-exercise blood samples. Neither vitamin E supplementation nor oestradiol concentrations influenced SOD and GPx activities or the susceptibility of the non-HDL fraction to oxidation while at rest. Plasma malondialdehyde concentration was unaffected by exercise, however significant reductions in erythrocyte SOD and GPx activities and increased susceptibility of the non-HDL fraction to oxidation were noted after exercise. Exercise-induced changes were reduced when oestradiol concentration was high in the preovulatory phase, independent of the serum vitamin E concentrations. In addition, both pre- (r = 0.58, P < 0.05) and post-exercise (r = 0.73, P < 0.001) GPx activities in placebo administered subjects were positively correlated with oestradiol concentrations. In conclusion, these findings suggest a better protective role of oestradiol against oxidative injury, compared to vitamin E. Exhausting muscle performance was, however, not influenced by vitamin E supplementation and/or cycle-phase related changes in oestradiol concentrations.