Erik W. Faria

The Science of Cycling Factors Affecting Performance - Part 2

AbstractThis review presents information that is useful to athletes, coaches and exercise scientists in the adoption of exercise protocols, prescription of training regimens and creation of research designs. Part 2 focuses on the factors that affect cycling performance. Among those factors, aerodynamic resistance is the major resistance force the racing cyclist must overcome. This challenge can be dealt with through equipment technological modifications and body position configuration adjustments. To successfully achieve efficient transfer of power from the body to the drive train of the bicycle the major concern is bicycle configuration and cycling body position. Peak power output appears to be highly correlated with cycling success. Likewise, gear ratio and pedalling cadence directly influence cycling economy/efficiency. Knowledge of muscle recruitment throughout the crank cycle has important implications for training and body position adjustments while climbing. A review of pacing models suggests that while there appears to be some evidence in favour of one technique over another, there remains the need for further field research to validate the findings. Nevertheless, performance modelling has important implications for the establishment of performance standards and consequent recommendations for training.

Nasal splinting effects on breathing patterns and cardiorespiratory responses

The aim of this study was to compare the effects of nasal splinting during different modes of breathing on breathing patterns and cardiorespiratory responses. Ten healthy subjects (4 males, 6 females) performed five maximal treadmill tests while breathing through the nose, nose + dilator, mouth, nose + mouth, and nose + mouth + dilator. Repeated-measures analysis of variance and Tukey HSD revealed no significant differences between trials for maximal oxygen consumption, minute ventilation at an oxygen consumption of 30 ml.kg-1.min-1, carbon dioxide production, respiratory exchange ratio, tidal volume, dead space to tidal volume ratio, or completed treadmill stages to exhaustion. No significant difference was found in subjective dyspnoea ratings between stages of nose versus nose + dilator breathing. Minute ventilation, ventilatory equivalent for oxygen, and breath frequency for nose and nose + dilator versus mouth, nose + mouth, and nose + mouth + dilator were significantly lower. Ventilatory equivalent for carbon dioxide was significantly lower for nose versus mouth, and nose + dilator versus nose + mouth + dilator breathing. End-tidal carbon dioxide was significantly higher in nose versus mouth, nose + mouth, and nose + mouth + dilator breathing, and in nose + dilator versus mouth breathing. Nose breathing revealed a significantly lower heart rate versus nose + dilator, mouth, nose + mouth, and nose + mouth + dilator breathing. These results suggest that nasal splinting during exercise has minimal effects when nasal breathing and no effects when oronasal breathing.

Cardiorespiratory responses to exercises of equal relative intensity distributed between the upper and lower body

The principles underlying the cardiorespiratory responses to upper body versus lower body exercise remain unclear. We explored the hypothesis that workloads of the same percentage of maximum strength for a particular part of the body might elicit similar cardiovascular responses. Twelve trained female university rowers (mean +/- s: age, 22.8 +/- 1.3 years; body mass, 66.9 +/- 1.8 kg; height, 169 +/- 6 cm; body fat, 18 +/- 2%; HRpeak, 190 +/- 3 beats min(-1); VO2 peak, 50.7 +/- 2.6 ml kg(-1) min(-1)) performed four 12 min exercise trials on a rowing ergometer. Arm rowing, leg extension and arm rowing + leg extension workloads were set at 20% of the mean of their respective three-repetition maximum (3-RM). The combination of arm rowing and leg extension was also performed in a reciprocal workload fashion; that is, the arm workload was 20% of the mean 3-RM for leg extension, and the leg extension workload was 20% of the mean 3-RM for arm rowing. Analysis of variance and Tukey HSD showed that, although the power output for leg extension was 144% higher than for arm rowing, the mean VO2, VE and heart rate values were not significantly different between exercise modes. Oxygen uptake for reciprocal arm rowing + leg extension, with the arms performing 71% of the total power output, was not significantly different from non-reciprocal arm rowing + leg extension; however, the VE and heart rate values were higher. Our results suggest that, during submaximal exercise, cardiorespiratory responses to upper body exercise do not differ significantly from those to lower body exercise, so long as the upper and lower body workloads are set at an equal relative strength level.

Effect of exercise and nasal splinting on static and dynamic measures of nasal airflow

The main aim of this study was to assess the separate and combined effects of exercise and nasal splinting on static and dynamic measures of nasal airflow. In a randomized crossover design, 12 healthy participants (6 men, 6 women) performed static and dynamic spirometric nasal airflow assessment tests, with or without nasal splinting (Breathe-Right™), before and after a maximal oxygen uptake (VO 2max ) treadmill test. At least 7 days later, the V O 2max and nasal airflow tests were repeated. The results showed that the measured variables were not significantly different with and without nasal splinting. We conclude that the absence of significantly enhanced nasal patency observed for nasal splinting and after exercise suggest that these factors have a minimal impact on nasal airflow volume and rate.