ABSTRACT
ABSTRACT Different competitive environments appears to affect the physical demands during the sports competitions. Thus, the aim of this study was to report the mechanical demand and pacing behaviour of twelve male elite mountain bikers on cross-country short track (XCC) and cross-country Olympic (XCO). During both competition, total race time, speed, power output (PO) and cadence (CA) were recorded. As the race time in the XCC is shorter (21.0 ± 0.5 vs 84.0 ± 3.0 min; p<0.01), the average speed (26.6 ± 0.6 vs 17.8 ± 0.6 km/h; p<0.01), PO (365.0 ± 26.7 vs 301.0 ± 26.2 watts; p<0.01) and CA (81.2 ± 4.7 vs 77.4 ± 4.3 rev∙min−1; p=0.01) were higher than the XCO. While a variable pacing was adopted during XCC, a positive profile was adopted in XCO. In addition, athletes adopted a more conservative starting pace during XCC (below average race speed) but a faster start during XCO (above average race speed). These findings demonstrated that mechanical parameters and pacing profile adopted by cyclists are different between XCC and XCO. Therefore, mountain bikers and coaches must develop specific strategy and training methods in order to obtain success in each competition.
RESUMO Diferentes ambientes competitivos parecem afetar as demandas físicas durante as competições esportivas. Assim, o objetivo deste estudo foi reportar as demandas mecânicas e o comportamento do pacing de doze homens ciclistas de montanha da categoria elite durante o cross-country de pista curta (XCC) e o cross-country Olímpico (XCO). Durante ambas as competições, o tempo total de corrida, velocidade, potência (PO) e cadência (CA) foram gravados. Como o tempo de prova do XCC é menor (21,0±0,5 vs 84,0±3,0 min; p<0,01), a velocidade média (26,6±0,6 vs 17,8±0,6 km/h; p<0,01), PO (365,0±26,7 vs 301,0±26,2 watts; p<0,01) e CA (81,2±4,7 vs 77,4±4,3 rev∙min−1; p=0,01) foram maiores que no XCO. Enquanto um ritmo variável foi adotado no XCC, um perfil positivo foi adotado no XCO. Além disso, os atletas adotaram um ritmo inicial mais conservador durante o XCC (abaixo da velocidade média da prova), mas um início mais rápido durante o XCO (velocidade acima da média da prova). Esses achados demonstraram que os parâmetros mecânicos e o ritmo adotados pelos ciclistas são diferentes entre o XCC e XCO. Portanto, ciclistas e treinadores devem desenvolver estratégias e métodos de treinamento específicos para obter sucesso em cada competição.
ABSTRACT
Obesity is a major global health problem. It is now commonly seen in young population due to their lifestyle and unhealthy eating habits. Obesity is now more common in younger females. Due to hormonal changes, body may not adapt, which may lead to life threatening and irreversible conditions. Obesity affects many physical factors including gait and balance. We wanted to study the correlation between obesity and gait-balance parameters, the effect of multi component exercise program on selected gait and balance parameters in young obese females. We also wanted to study its effect on dynamic balance, and compare it with conventional exercise program.METHODSIn this comparative study two groups were created with 20 participants with obesity grade 1 BMI in each. Group 2 underwent 26 weeks of multi component exercise. Group 1 underwent conventional exercises. Data was assessed and analysed. Outcome measures were body mass index, base of support, stride length, step length, cadence, and functional reach test.RESULTSBody mass index for group 1 after their conventional exercise decreased in 47% while in group 2 with multi component exercise protocol BMI reduced in 53% population. Similarly base of support for group 1 was 42% and group 2 was 58%; stride length in group 1 was 42% and group 2 was 58%; step length for group 1 was 42% and group 2 was 58%; cadence for group 1 was 42% and group 2 was 58%; functional reach test was 42% and 58% for group 1 and group 2 respectively.CONCLUSIONSA significant improvement was found in selected gait and balance parameters in young obese women with the help of multi component exercise program.
ABSTRACT
Introduction: Cadence and step length are important biomechanical variables of walking and running but they are not typically monitored by the treadmills. This study explains a novel non-invasive method to estimate the step length of walking and running to maximize the professional skills and scientific capabilities of Physiotherapists and Exercise professionals. Methodology: Seventeen individuals (10 men and 7 women) who have been undergoing supervised fitness training programs were selected for the biomechanical analysis of the relationship between cadence and step length of walking and running on the treadmill in the speeds ranging from 5 Km/h to 15 Km/h for men and 5 Km/h to 12 Km/h for women. Results: Exercisers displayed wide range of step length strategies to manage the walking and running speeds opted for the experiment. Additionally, when the same exercisers were allowed to exhibit their maximum running speed in the outdoor environment, a statistically significant difference was found because all of them faced psychological constraints to explore or sustain their fastest running ability on the treadmill. Conclusion: Assessment of cadence and step lengths of the patients and exercisers looks indispensable. Visual counting method to calculate the cadence can be easily acquired through practice, usually accompanied by the development of the skill to compute the step lengths using mathematical formulae. The same method can be used to ascertain if the individuals are adapting symmetrical or asymmetrical step lengths by just separately counting the number of steps produced by each lower extremity for a specific time length (30 seconds or 60 seconds). Experts should continue exploring such feasible, non-invasive and inexpensive diagnostic procedures.
ABSTRACT
The purpose of this study was to compare the thigh muscle oxygenation state of competitive road cyclists and non-cyclists during varied pedaling frequency cycling. Six male college road cyclists (CY group) and five male students (NC group) performed four sets of cycling bouts, consisting of 2 minutes of warm up (60 rpm, 50 watts) followed by 5 minutes of pedaling (150 watts) using an electro-magnetic braked cycle ergometer at 40, 60, 90, and 120 rpm. Oxygenated hemoglobin and/or myoglobin (Oxy-Hb/Mb) and deoxygenated Hb/Mb (Deoxy-Hb/Mb) concentrations in the vastus lateralis were measured by near infrared spatially resolved spectroscopy. The Oxy-Hb/Mb level was significantly higher in the CY group than the NC group. But there was no significant intraction effect of the group and pedaling rate on the Oxy-Hb/Mb level. These results suggest that the changes in muscle oxygenation state according to pedaling cadence do not differ between cyclists and non-cyclists. And though the whole body work efficiency decreased according to increasing pedaling cadence, Oxy-Hb/Mb and Deoxy-Hb/Mb levels in the vastus lateralis remained unchanged up to 90 rpm. However, at 120 rpm, the Oxy-Hb/Mb level decreased remarkably and the Deoxy-Hb/Mb level increased. These results suggest that deoxygenation in the vastus lateralis at 120 rpm was higher than that for lower frequencies. And, conversely, oxygen uptake in the vastus lateralis might have increased steeply at 120 rpm. It may be that the maximum pedaling cadence that would not reduce work efficiency in the vastus lateralis is around 90 rpm.