The purpose of this study was three-fold: (1) to characterise both the on- and off-transient oxygen uptake (V(.)O(2)) kinetics in endurance runners during moderate-intensity treadmill running; (2) to determine the degree of symmetry between on- and off-transients; and (3) to determine the reproducibility of V(.)O(2) kinetic parameters in endurance runners. Twelve endurance-trained runners [mean (SD) age 25.2 (4.7) years, body mass 70.1 (9.7) kg, height 179.5 (7.5) cm, ventilatory threshold (V(T)), 3,429 (389) ml.min(-1), maximal V(.)O(2) (V(.)O(2max)) 4,138 (625) ml.min(-1)] performed two multiple square-wave transition protocols on separate days. The protocol consisted of six (three transitions, 15 min rest, three transitions) square-wave transitions from walking at 4 km.h(-1) to running at a speed equivalent to 80% of the V(.)O(2) at the V(T) (80%V(T)). To determine the reproducibility, the protocol was repeated on a separate day (i.e. a test-retest design). Pulmonary gas-exchange was measured breath-by-breath. The V(.)O(2) data were modelled [from 20 s post-onset (or offset) of exercise] using non-linear least squares regression by a mono-exponential model, incorporating a time delay. The on- and off-transient time constants (tau(on) and tau(off)), mean response times (MRT(on) and MRT(off)) and amplitudes (A(on) and A(off)) were obtained from the model fit. On- and off transient kinetics were compared using paired t-tests. The reproducibility of each kinetic parameter was explored using statistical (paired t-tests) and non-statistical techniques [95% limits of agreement (LOA, including measurement error and systematic bias) and coefficient of variation (CV)]. It was found that the tau(on) [12.4 (1.9)] was significantly (P<0.001) shorter than tau(off) [24.5 (2.3) s]. Similarly, MRT(on) [27.1 (1.9) s] was shorter than MRT(off) [33.4 (2.2) s]. With respect to the reproducibility of the parameters, paired t-tests did not reveal significant differences between test 1 and test 2 for any on- or off-transient V(.)O(2) kinetic parameter (P>0.05). The LOA for tau(on) (1.9 s), tau(off) (2.3 s), MRT(on) (1.2 s), MRT(off) (3.2 s), A(on) (204 ml.min(-1)) and A(off) (198 ml.min(-1)) were narrow and acceptable. Furthermore, the measurement error (range, 4.3 to 15.1%) and CV (1.3 to 4.8%) all indicated good reproducibility. There was a tendency for tau(off) to be more reproducible than tau(on). However, MRT(on) was the most reproducible kinetic parameter. Overall, the results suggest that: (1) a multiple square-wave transition protocol can be used to characterise, reproducibly, both on- and off-transient V(.)O(2) kinetic parameters during treadmill running in runners; (2) the phase II time constant is independent of V(.)O(2) (max), and (3) asymmetry exists between on- and off transient V(.)O(2) kinetic parameters.

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The aim of the study was to examine whether a measure of oxygen uptake (VO2) kinetics could differentiate between 12 elite male endurance (3000-10,000 m) runners and 12 elite male sprint (100-400 m) runners using a pseudo random binary sequence (PRBS) exercise protocol. All exercise tests were performed on an electrically braked cycle ergometer at a constant pedal frequency of 1 Hz. The PRBS exercise intensities alternated between 25 W and 85 W for three consecutive PRBS cycles of 300 s. VO2 was measured breath-by-breath and results were analysed by Fourier techniques in the frequency domain. Blood lactate concentrations taken pre and post testing were below 2 mM. Significantly greater amplitude components were observed in the endurance runners than sprinters at frequencies 6.7 mHz (6.71 +/- 1.09 and 5.47 +/- 0.95 ml x min(-1) x W(-1), respectively) P<0.05 and 10 mHz (4.97 +/- 0.98 and 3.56 +/- 0.69 ml x min(-1) x W(-1) respectively) P<0.01. Phase shift components were significantly shorter in the endurance runners compared to the sprinters at frequency 3.3 mHz (-35.45 +/- 4.31 and -41.26 +/- 5.82 degrees respectively) P<0.05. The results of this study show that VO2 kinetics are differentially faster in elite endurance runners than in elite sprinters. This supports the development of the PRBS technique as a test of sports performance.

Opinions differ about the nature, frequency and relative assessment weight of coursework in a mathematics degree. Short frequent coursework may aid week by week engagement while a smaller number of longer tasks may be better linked to real applications and give more opportunity for open ended questions. What should be the mix between assessment types? To what extent is copying a problem and how should this be balanced against the opportunity coursework can afford for investigation and originality? Given the heavy dependence on marks for motivation, the award of some credit to formative assessment encourages students to engage with course material. Colleagues see the advantages of frequent small tasks with rapid feedback as aiding students both to keep up with material delivered at a far faster pace than at school, and in encouraging attendance at tutorials. Conversely a smaller number of longer assignments encourages reflection about the interrelation of different parts of the course material and gives practice in the various stages of applying mathematics. Student reactions generally support colleagues' views about the merits and possible limitations of each approach.

The purpose of this study was to compare the test-retest reliability of oxygen uptake (VO2) kinetics with carbon dioxide output (VCO2) kinetics using a pseudo random binary sequence (PRBS) exercise test. A reliable test of gas exchange kinetics would have the potential of being applied as a sports fitness test. Ten healthy male subjects agreed to participate in the study and all subjects completed two identical PRBS exercise tests (test 1 and test 2), separated by a 30 min period of inactivity. Three consecutive 300 s PRBS cycles were completed in each test with 20 s exercise intensity changes between 25 and 85 W using an electrically braked cycle ergometer. Fourier analysis was computed for frequencies 3.3, 6.7 and 10 mHz. Statistical analysis by two-way ANOVA with repeated measures did not reveal significant differences between test 1 and test 2 for either VO2 kinetics or VCO2 kinetics. Static gain of VO2 for test 1 [9.11 (SD 0.59) ml.min-1.W-1] and test 2 [9.23 (SD 0.64) ml.min-1.W-1] did not differ significantly between tests. The 95% limits of agreement for VCO2 kinetics displayed increased variability in comparison to VO2 kinetics at each frequency of amplitude ratio and phase shift. Systematic bias ranged between 0% and 4%, except at frequency 10 mHz of VCO2 kinetics phase shift which showed a 10% bias for slower VO2 kinetics in test 2. It is possible that the increased variability of VCO2 kinetics compared to VO2 kinetics might be attributable to a lower signal to noise ratio in VCO2 kinetics, variations in ventilation or the storage mechanisms of CO2. The lower variability of VO2 kinetics compared with VCO2 kinetics suggests that the PRBS test of VO2 kinetics has the greater potential for further development as an indicator of aerobic fitness.