Comparison of methods for determining power generated on a rope-braked cycle ergometer during low-intensity exercise

This study compares the instrumentation and analysis techniques used when determining the power expended pedalling a rope-braked ergometer manufactured by Monark (Sweden) during a low intensity test. Power values were generated by eight subjects. The instrumentation consisted of load cells to measure the rope brake forces, a tachometer to measure the flywheel velocity and instrumented pedal cranks manufactured by Schoberer Rad Messtechnik (SRM). The subjects pedalled a rope-braked ergometer at 60 rev min^-1, against a resistance of 3 kg, for 5 minutes. Three different measurements of the mean power were recorded and these were compared with the value given by Monark. The SRM cranks provided two sets of results using different software packages supplied with the cranks. SRM standard software is used for taking measurements during training and cycle races over long time periods. An additional piece of software is provided by SRM called Ptnew, which gives readings of torque and pedal cadence over periods up to 30 seconds. Using the values supplied by Monark each subject generated 180 W of power. The mean power for the eight subjects, measured using the SRM cranks, was 170.36 W (SD 4.11) using the alternative SRM software (Ptnew) over a 30 second period and 173.68 W (SD 2.21) using the standard SRM software. From the direct measurement of the brake forces and flywheel velocity the mean power across the eight subjects was 148.90 W (SD 5.89). The SRM cranks measure the input power, whereas the direct measurement system measures the power output excluding mechanical losses. These values give a figure for the mechanical efficiency for the roped-braked ergometer of 88%. It was found that Monark overestimates the power generated by the subjects when compared with both the SRM systems and the direct measurement instrumentation.     

THE ROLE OF THE INTERNATIONAL ASSOCIATION OF ACADEMIES OF SCIENCE IN INTERNATIONAL COOPERATION

The political changes occurring in eastern and central Europe in 1989 and 1990 and the breakup of the Union of Soviet Socialist Republics in 1991 fragmented a large area in which science and technology policy was more or less centralized and rationalized. Each country in this area, as a result, has had to develop its own science and technology policy in very difficult situations of transition. One of the attempts made to re‐establish some order and unity in science policy in the former socialist countries has been spearheaded by the International Association of Academies of Sciences, founded in Kiev in 1991. It is attempting, on a voluntary basis, to assume some of the functions of the former Soviet Academy of Sciences, and in particular, to re‐create the scientific space existing before 1989‐1991. Among its many projects are efforts in favour of young scientists and closer co‐operation with other international organizations of academies.