Ergometers

A bicycle ergometer is a stationary bicycle that is used to produce a measured level of effort (typically watts) appropriate for the test situation. A braking device consumes the power produced through the bike in the test. This braking device can be a mechanical band around a drum, a set of brake pads on a wheel, a wind generator, (fan) or an electromagnetic brake. Electromagnetic braking is the most advanced method and is the easiest to connect to automated control. The bicycle ergometer should have enough rotating mass to provide a smooth pedaling motion.

Bicycle ergometers are often preferred for exercise testing, since they can produce a direct and relatively accurate measurement of the amount of power produced in the test. This is important in three separate exercise scenarios:

• Maintaining a steady increase in power up to maximum. (ramp)
  
  
• Using uniform steps in output power up to a maximum. (stepped)
  
  
• Maintaining a constant level of output power over an extended period. (steady-state)

Not all ergometers will be suitable for all situations. Many top athletes will require a higher level of power capacity than the less expensive ergometers can handle.

Treadmills

Treadmills are preferred when testing runners. The ability to program the treadmill to produce a stepped or ramp effort is critical. Motorized elevation control and automated speed functions can provide this capability. For safety reasons, the treadmill should have a kill switch that shuts off the treadmill if the runner gets too far off the back. Athletes at maximum stress level may not have all of their faculties at a normal level. Safety concerns are more important on a treadmill.

Note that performance indicators will be different depending on the setting. An athlete will have a higher heart rate at anerobic threshold when running than when riding a bicycle due to differences in the muscles used. Different mental states and times of day can cause differences well. A triathlete may need or want testing on both a treadmill and an ergometer.