Concurrent validity of power output derived from the non-motorised treadmill test in sedentary adults

<p><b>INTRODUCTION</b>Many consider the Wingate Anaerobic Test (WAnT) as a reference standard assessment mode in the measurement of lower limb short-term power output. However the WAnT is criticised for having low ecological validity, in non-cycling tasks and is reliant on a predetermined applied force, which might not elicit the highest power output. A viable alternative to the WAnT is the Non-Motorised Treadmill (NMT) Test, which allows for power measurement in all-out intensity effort sprint-running. With the reliability of the NMT to elicit power in sedentary adults already established, the aim was to compare peak power (PP) and mean power (MP) derived from a 10-s sprint on the NMT to that derived from a 10-s WAnT, to establish concurrent validity.</p><p><b>MATERIALS AND METHODS</b>Twelve male [age 26.6 +/- 2.4 years, body mass (BM) 63.0 +/- 7.2 kg] and 11 female (age 25.3 +/- 3.6 years, BM 51.0 +/- 4.0 kg) sedentary adults participated in the study. PP and MP in absolute, ratio-scaled and allometrically-scaled to BM were analysed. Ratio limits of agreement (LOA) was used to establish the agreement between PP and MP from the NMT and the WAnT.</p><p><b>RESULTS</b>PP in absolute and ratio-scaled to BM from the NMT was between 1.04 and 1.12 times that of PP from the WAnT in 95% of the attempts (PP: NMT, 647.1 +/- 176.4W vs WAnT, 597.0 +/- 146.0W). MP in absolute and ratio-scaled to BM from the NMT test was between 0.88 and 0.97 times of that from the WAnT (MP: NMT, 508.9 +/- 130.7W vs WAnT, 548.7 +/- 131.3W). Power produced on the NMT and the WAnT by sedentary adults shared moderate and acceptable levels of agreement.</p><p><b>CONCLUSIONS</b>These results affirmed that the NMT could be considered as a viable alternative to the WAnT for the assessment of PP and MP in allout intensity sprint-running lasting 10 s in sedentary adults.</p>

Modelling maximal oxygen uptake in athletes: allometric scaling versus ratio-scaling in relation to body mass

<p><b>INTRODUCTION</b>Maximal oxygen uptake, V&O2 peak, among athletes is an important foundation for all training programmes to enhance competition performance. In Singapore, the V& O2 peak of athletes is apparently not widely known. There is also controversy in the modelling or scaling of maximal oxygen uptake for differences in body size - the use of ratio-scaling remains common but allometric scaling is gaining acceptance as the method of choice.</p><p><b>MATERIALS AND METHODS</b>One hundred fifty-eight male (age, 21.7 +/- 4.9 years; body mass, 64.8 +/- 8.6 kg) and 28 female (age, 21.9 +/- 7.0 years; body mass, 53.0 +/- 7.0 kg) athletes completed a maximal treadmill run to volitional exhaustion, to determine VO2 peak.</p><p><b>RESULTS</b>V& O2 peak in L/min of female athletes was 67.8% that of male athletes (2.53 +/- 0.29 vs. 3.73 +/- 0.53 L/min), and V& O2 peak in mL/kg BM1.0/min of female athletes was 83.4% of male athletes (48.4 +/- 7.2 vs. 58.0 +/- 6.9 mL/kg BM1.0/min). Ratio-scaling of V& O2 peak did not create a size-free variable and was unsuitable as a scaling method. Instead, V& O2 peak, that was independent of the effect of body mass in male and female athletes, was best described using 2 separate and allometrically-derived sex-specific regression equations; these were V& O2 peak = 2.23 BM0.67 for male athletes and V& O2 peak = 2.23 BM0.24 for female athletes.</p>

Young People and Exercise-Induced Asthma

In many developed and developing countries, asthma is thought to be the most common chronic illness in childhood and it appears to be increasing in prevalence. Bronchial hyper-responsiveness [breathlessness, fatigue, chest pain, etc] to various stimuli, including exercise, is the most specific sign of asthma. Typically exercise-induced asthma [EIA] consists of coughing, wheezing, chest tightness, chest pain or any combination of these symptoms during exercise, or more so, about eight to 15 minutes after exercise. The symptoms of EIA are usually resolved between 30 and 90 minutes. A proper warm-up before strenuous physical activity and a warm-down following exercise appear to offer some protection from EIA. Prevention is the main objective in managing EIA. Some of these precautions can include: [i] an appropriate warm up before vigorous exercise and a gradual warm down after the exercise; [ii] covering the nose and mouth with a mask or a scarf whilst exercising in cool environments; [iii] exercising only in warm and humidified environments; and [iv] improving the baseline fitness of young people who have asthma. The physical fitness and exercise performance of young people with asthma appear to be inferior to those of young people without asthma, but this could be due to their diminished levels of physical activity and unnecessary avoidance of exercise because of the disease. Young people with asthma can benefit from exercise programmes that help raise their levels of physical fitness, especially aerobic fitness. With the proper use of prescribed medication and effective asthma management, young people with asthma are capable of high levels of performance, and need not forego the health benefits that can be harvested with a regime of life-long exercise