P. Goossens’s research while affiliated with Vrije Universiteit Amsterdam and other places

Since body balance and weight-bearing factors present while running on the treadmill might cause additional muscle recruitment and thus could influence the force-velocity relationship and power, the present study was undertaken to find out whether the F-V and F-P relationships measured while running on the treadmill are different from the respective indices measured during cycling. On two separate occasions, 32 male subjects were tested using a series of 5 sec, all-out sprints against different braking forces on the Gymrol Sprint treadmill and on the Monark ergometer. The maximal peak power (PPmax) and maximal mean power (MPmax) were measured. The equation: EP = 0.5 maximal force (Fo) x0.5 maximal velocity (Vo) was used to calculate the estimated values of peak power (EPP) and mean power (EMP). The F-V relationship was linear in both cycle ergometer and treadmill measurements. PPmax, MPmax, EPP, and EMP values on the treadmill were lower than the respective values on the ergometer. EPP on the ergometer and on the treadmill, as well as EMP values on the ergometer, were slightly higher than the corresponding measured values of PPmax and MPmax. The levels of braking force at which PP, MP, PPmax, and MPmax were obtained were lower on the ergometer than on the treadmill. High correlation coefficients were found between PPmax, MPmax, EPP, and EMP measured on the ergometer and on the treadmill (r = 0.86, r = 0.84, r = 0.71, r = 0.78, respectively, P<0.01). In both tests, significant relationships between PPmax, MPmax, EPP, and EMP were observed. It is concluded that independent of the type of ergometry the force-velocity relationship is similar in the measured range of velocities which suggests that the number of muscle groups and joints engaged in movement are more important than body balance and weight-bearing factors present while running on a treadmill.

The purpose of this study was to estimate the gross body force‐velocity (F‐V) relationship on a newly developed motorized treadmill (Gymrol, France) in subjects who differed in their predicted maximal running velocity (Vmax) calculated from the F‐V relationship. Of the 32 subjects tested, those with the 14 highest Vmax values were assigned to a fast group (FG) and those with the lowest 13 Vmax values to a slow group (SG). The F‐ V relationship during two testing sessions was obtained from six 5‐s, all‐out sprints against different resistance settings that were 5%, 8%, 10%, 13%, 15% and 20% of the maximal value the treadmill could produce. The F‐V relationship fitted a linear regression in both groups. The individual correlation coefficients for the F‐ V relationship during the first session ranged from —0.992 to —0.997, and during the second session from —0.989 to —0.998, with no significant differences between sessions. The Vmax was significantly higher in FG (Vmax = 7.20±0.32m/s) than in the SG (Vmax = 5.96 ± 0.39 m/s) (P < 0.05). Compared with the SG, the FG had a higher maximal power, taken as the highest power value regardless of the resistance at which it occurred (3033 ±461 W and 2633 ± 412 W, respectively) (P < 0.05). The velocity at the resistances of 5% (68 N) to 13% (176N) was higher in FG than in SG. Power was also higher in FG compared to SG at all resistances, with no significant difference at 176 N and 270 N.It was concluded that the linear F‐ V relationship measured on the treadmill was independent of the subject's maximal running speed. However, the two linear F‐ V relationships became more disparate at resistances lower than 176N, showing a greater velocity in a subject with a higher maximal running speed. The subjects with a higher maximal speed also developed higher power on the tested resistance range. The differences between groups might be due to their different muscle architecture and to the higher fast‐twitch fiber composition in subjects from the FG compared with that from the SG.

The aim of this study was to estimate the optimal resistance on a specially designed motorized treadmill (Gymrol) to obtain instantaneous peak power (IPP), 1‐second peak power (PP), and 5‐second mean power (MP) during running in subjects with different body sizes and athletic backgrounds. Thirty‐five male subjects were divided into four groups: control, power, cyclists, and miscellaneous. Two sessions of 5‐second all‐out sprints were performed against resistances that were 5, 8, 10, 13, 15, and 20% of the treadmill's maximal resistance of 1352 N. The power produced for propulsion (horizontal power) was measured. There was no difference in any set of power variable measurements between the first and the second session. A test‐retest reliability coefficient of r = 0.89, r = 0.84, and r = 0.80 for each of the MP, PP, and IPP tests, respectively, was measured. The IPP values (range, 2419 to 2934 W) were three to three and one‐half times higher than those for PP (range, 764 to 1014 W) and MP (range, 657 to 868 W). The absolute value of IPP did not show a difference between any two groups but PP was significantly higher in the power group. Group mean anthropometric measures were also recorded and correlated with the different power outputs when each power variable was related to body mass, lean body mass, or lean leg volume. There was no difference between group sets in the measurement of PP and MP, but IPP was significantly lower in the power group compared with the other groups. The optimal resistance required for all groups, except cyclists, needed to be higher to measure PP than to measure IPP. The results showed that there is an optimal resistance setting (10, 13, and 15%) needed to make an accurate determination of anaerobic power, as measured on this type of treadmill.