Differences between treadmill and cycle ergometer cardiopulmonary exercise testing results in amateur triathletes and their association with body composition and body mass index

Cardiopulmonary exercise testing (CPET) is the method of choice to assess aerobic fitness. Previous research was ambiguous as to whether treadmill (Tr) and cycle ergometry (CE) results are transferrable or different between testing modalities in triathletes. The aim of this paper was to investigate the differences in HR and VO2 at maximum exertion and at anaerobic threshold (AT) and respiratory compensation point (RCP) and evaluate their association with body fat (BF), fat free mass (FFM), and body mass index (BMI). 143 adult (n = 18 female), amateur, Caucasian triathletes had both Tr, and CE CPET performed. The male group was divided into < 40 years (n = 80) and > 40years (n = 45). Body composition was measured with bioelectrical impedance before tests. Differences were evaluated using paired T-tests and associations were evaluated in males using multiple linear regression (MLR). Significant differences were found in VO2 and HR at maximum exertion, at AT and at RCP between CE and Tr testing, in both males and females. VO2AT was 38.8(± 4.6) ml/kg/min in Tr vs 32.8(± 5.4) in CE in males and 36.0(± 3.6) vs 32.1(± 3.8) in females (p < 0.001). HRAT was 149 (± 10) bpm in Tr vs 136 (± 11) in CE in males and 156 (± 7) vs 146 (± 11) in females (p < 0.001). VO2max was 52 (± 6) ml/kg/min vs 49 (± 7) in CE in males and 45.3 (± 4.9) in Tr vs 43.9 (± 5.2) in females (p < 0.001). HRmax was 183 (± 10) bpm in Tr vs 177 (± 10) in CE in males and 183 (± 9) vs 179 (± 10) in females (p < 0.001). MLR showed that BMI, BF and FFM are significantly associated with differences in HR and VO2 at maximum, AT and RCP in males aged > 40. Both tests should be used independently to achieve optimal fitness assessment and further training planning.

Relationship between maximal aerobic power with aerobic fitness as a function of signal-to-noise ratio

Optimized methods for cardiorespiratory health evaluation are of great interest for public health. Moderate exercise protocols might be as good as maximum exertion exercise protocols to evaluate cardiorespiratory health. Pseudorandom or constant workload moderate exercise can be used to evaluate cardiorespiratory health.

Comparison of Biomechanical Human Neck Models: Muscle Forces and Spinal Loads at C4/5 Level

This study developed a three-dimensional biomechanical model to investigate the internal loads on the human neck that result from isometrically generated loads resisted by a force on the head. The first goal was to apply the double-optimization (DOPT) method, the EMG-based method, and the EMG assisted optimization (EMGAO) method to the neck model, calculating muscle forces and C4/5 cervical joint loads for each method. The second goal was to compare the results of the different methods, and the third was to determine maximum exertion forces in the cervical spine for isometric contractions. To formulate the EMG-based model, electromyographic signals were collected from 10 male subjects. EMG signals were obtained from 8 sites around the C4/5 level of the neck by surface electrodes, while the subject performed near maximum, isometric exertions. The mean maximum values (±SD) calculated for C4/5 joint compressive forces during peak exertions were 1654 (±308) N in flexion by the EMG method, 1674 (±319) N in flexion by the EMGAO method, and 1208 (±123) N in extension by the DOPT method. In contrast to the DOPT method, the EMG and EMGAO methods showed activation of all the muscles, including the antagonists, and accommodated various load distribution patterns among the agonist muscles during generation of the same magnitude of moments, especially in lateral bending. The EMG and EMGAO methods predicted higher cervical spinal loads than previously published results by the DOPT method. These results may be helpful to engineers and surgeons who are designing and using cervical spine implants and instrumentation.

Age Effects in Biomechanical Modeling of Static Lifting Strengths

There is growing awareness that age results in reduced strengths in the population, and that significant decreases start in the 5th decade. The magnitude of the decrease in strength depends on the specific muscle function being tested. Because of differential effects it is not clear how various decreases could alter whole-body strength performance. This paper describes how specific strength decreases measured in an older population of men and women could affect their whole-body exertion capabilities in selected scenarios. A computerized strength prediction program is used to both predict the whole-body strength changes with age, and to study how older populations can alter their postures to achieve maximum exertion capability. The results indicate that different muscle group strengths decline by 5% to 70% with age, depending on which muscle group is tested. These changes have profound effects on whole-body exertion capabilities, which also are shown to depend on specific postures used to perform the exertions.

Wheel Turning Strength for Four Wheel Designs

This paper reports the results of an experiment to evaluate the isometric wheel turning strength of 12 male and 12 female subjects using four different wheel designs. Three of the wheels investigated were new designs developed specifically for this study, while the fourth was a wheel currently used on many railroad car hand brakes. The three new designs considered were a cylindrical tube (4.3 cm in diameter), a cylindrical tube (2.5 cm in diameter) with spheres mounted along the edge, and a circular zig-zag design. Strength data were collected using a mock-up of the ladder and platform arrangement found on most railroad hopper and box cars. The task simulated the final tightening exertion required to secure railroad car hand brakes. Strength capabilities were measured using two methods: 1) a three second average during a six-second trial; 2) the peak reached on a separate trial in which subjects did not sustain an exertion. Results showed that the torque generated by the subjects was highest for the zig-zag design, followed in order by the wheel with the spheres, the cylindrical wheel, and the standard wheel; average torque values were 191 Nm, 147 Nm, 132 Nm, and 95 Nm, respectively. The average strength values (three-second average) for six-second maximum exertions produced lower average torque values (122 Nm) than the ramp to maximum exertion (161 Nm).

Isometric Strength Capability for a Vertical Wheel Turning Task

This paper reports on the measured isometric strength capability of 125 male and 125 female college students performing a one-handed wheel turning task. Three measures of isometric strength were used: (1) a three-second average of steady state levels taken from a six-second exertion, (2) the largest value (peak) from the same six-second exertion, and (3) a maximum exertion level taken from a separate “ramp-to-peak” exertion. Standardized whole-body strength measurements for the legs, arms, and torso as well as grip strength were also taken for each subject. The results presented in this paper demonstrate average isometric wheel turning strengths (torques) ranging from 109 to 152 N-m for males and 66 to 91 N-m for females, depending upon the strength measure used. The three strength measures were highly correlated, but produced significantly different estimates of strength. The three-second average produced the lowest estimate while the ramp-peak value produced the highest. Wheel turning strengths were also highly correlated with the standardized whole-body strength measures and with grip strength. Multiple regression models developed to predict wheel turning strength using these values accounted for 69 to 71 percent of the variation in the measures. The model results also suggest that grip strength plays an important role in determining wheel turning strength capability.

Glove Size and Material Effects on Task Performance

Two experiments were conducted to measure the effect of glove size and material on task performance. The first experiment tested the glove size and material effects on a maximum torque exertion task while the second experiment tested the glove size and material effect on a small parts assembly task. The results of the first experiment showed that for the maximum exertion task, the glove size had no significant effect while the glove material did have a significant effect. For the assembly task the results indicated that glove size and material combination may be important to performance.