This study wished to compare the same physiological responses of elite athletes to a typical intermediate term anaerobic capacity track running session with those of standing cycling of similar intensity and duration. Twelve well trained/elite male distance runners completed maximal running, standing cycling and strength testing sessions; and Intermediate Term Anaerobic Capacity Sessions (ITACS) in running and standing cycling; each comprising eight efforts of approximately 30 seconds duration at 90% maximal effort in each mode of activity, separated by 2 minutes rest. The experimental sessions took place from the end of November 1996 to the beginning of March 1997. The subjects were required to attend three maximal experimental sessions, which were performed on separate days and used for baseline data collection. On completing these they participated in both running and standing cycling ITACS, performed on separate days with at least 48 hours between each test protocol. There was complete randomisation of all test protocols. Descriptive statistics were determined for all the variables. Independent t-testing was used to determine if similar temperature and humidity readings were obtained during the maximal testing for each mode of activity. Paired t-testing was used to compare the differences in warmup heart rates between the maximal and ITACS, the differences in peak lactates obtained after each type of ITACS, draw comparisons between heart rate (HR) changes over time during the ITACS and determine if a difference existed between workloads for the two modes of activity. It was also used to draw a comparison between the peak BLa values and ascertain if pre-test creatine kinase (CK) levels were the same for each mode of activity. A repeated measures one way ANOVA was used to determine if workload reduced over time for each type of ITACS. A three way ANOVA with repeated measures on one factor (repetition) was performed on HR response. It was used to determine if there was a difference between the workload/recovery HR response; if workload/recovery HR values increased over the duration of each ITACS; and if the workload/recovery HR response over time was mode specific. A two way ANOVA with repeated measures on one factor (repetition) was performed on blood lactate (BLa) response. It was used to determine if there was a significant interaction between the mode of activity and time, if BLa increased over the duration of each ITACS and if there was an effect of mode on its own on the BLa response. A two way repeated measures ANOVA was used to ascertain whether there was a difference in CK levels between the two modes of activity, with Tukey's multiple comparison tests used in post hoc analyses to show the amount of difference. A linear regression analysis was performed to determine if BLa response was similar across the duration of each type of ITACS. The effects of temperature (22.3 ± 1.2 vs 21.1 ± 0.3 °C, run vs cycle, t = -0.94, n = 12, p = 0.36)) and humidity (57 ±4.2 vs 52 ± 1.7%, run versus cycle, t = -1.04, n = 12, p = 0.31) did not influence any of the results obtained during the ITACS. Nor did differing warmup intensities (as indicated by heart rate - HR) during the maximal (160 ± 5.7 vs 158 ± 3.1 beats per minute (bpm), run vs cycle, t = - 0.45, n = 9, p = 0.66) and ITACS (160 ± 3.6 vs 152 ± 3.1 bpm, run vs cycle, t = -2.81, n = 9, p = 0.02). An equal test preparation was confirmed by the warmup blood lactate (BLa) levels, which were not significantly different between the exercise modes for both the maximal (11.0 ±0.6 vs 11.8 ± 1.0 mmol-l1, run vs cycle, t = 2.26, ii n = 10, p =0.23) and ITACS (4.2 ± 0.7 vs 4.2 ± 0.6 mmol-1 ', run vs cycle, t = 0.27, n = 10, p = 0.796). A significantly higher workload was achieved during the running ITACS as compared to the standing cycling ITACS (105 ± 1.1 vs 89 ±2.9 %, run vs cycle, t = 10.45, n = 12, p<0.0005). The increase in workload/recovery HR response and their changes as each type of ITACS progressed was not mode specific [F(l,40) = 0.94, p > 0.05]. Those subjects who possessed high BLa concentrations performed less work on the cycle ergometer. There was a strong negative relationship for average workloads and BLa accumulation for the standing cycling exercise (Spearmans rho = -0.799, n = 11, p<0.005) suggesting that BLa accumulation was a limiting factor in work production. The increase in BLa levels was not mode specific F(l,20) = 1.36, p > 0.05]. The BLa response was comparatively similar because the rate of increase in BLa accumulation and peak BLa values (19.7 vs 16.9 mmol-l'1, cycle vs run, t = 2.1, n = 11, p = 0.06) were not significantly different between the modes of activity. Mode in conjunction with time affected standing cycling BLa response to a greater extent than running BLa levels [F(4.80) =3.929, p <. 0.05]. Standing cycling BLa concentrations were significantly negatively correlated with knee extension peak torque (Spearmans rho = - 0.771, n = 11, p < 0.01) and total work (Spearmans rho = - 0.802, n = 11, p < 0.01) measurements. In running they were negatively correlated with knee flexion total work measurements (Spearman rho = - 0.685, n = 11, p < 0.05) These findings suggest that BLa accumulation occurs from different muscle fibre recruitment patterns. Less work was performed in isokinetic knee extension following standing cycling as compared to running (2234 ± 68.4 vs 2462 ± 78.9 Nm, t = 2.23, n = 11, p < 0.05) suggesting that standing cycling is more fatiguing on the quadriceps than running. There was no difference in the knee flexion testing (1799 ± 89.6 vs 1785 ± 69.2, cycle vs run, t = 2.23, n = 11, p = 0.96). There was a significant difference in mean creatine kinase (CK) activity between the two modes 24 hours after completing the ITACS (450 ± 73.2 vs 320 ± 46.5 I/U, running vs cycle, F = 6.44, df = 1,17, p < 0.01). There was a significantly greater increase in CK activity and therefore muscle damage, following the running (mean increase of 190 I/U) as compared to the standing cycling session (mean increase of 44.0 I/U). In terms of reducing the risk of injury, achieving a similar cardiovascular response and achieving comparable BLa accumulation (even though mechanism/s of accumulation may be different) standing cycling appears to be is a satisfactory substitute for running during an ITACS. The results of this research strengthen the concept of utilising a simulated mode of activity as a substitute for the primary activity in order to maximise transfer effects, providing there is a careful balance between the specific training and the near specific training. The differing physiological responses between the exercise modes (ie- different muscle fibre recruitment patterns, different workload capacity, different CK measures) suggest that standing cycling cannot act as a total/comprehensive replacement for running. A training study is warranted to further investigate the findings of this research.