Modification of the Monark bicycle ergometer for underwater exercise

Area of Science:

• Exercise Physiology
• Biomedical Engineering
• Sports Science

Background:

• Standard bicycle ergometers are limited in their application for underwater exercise.
• Modifications are needed to adapt land-based exercise equipment for aquatic environments.

Purpose of the Study:

• To modify a Monark bicycle ergometer for underwater exercise.
• To develop a formula for predicting oxygen uptake (VO2) based on ergometer modifications and pedaling speed.
• To evaluate the advantages of the modified ergometer for aquatic exercise.

Main Methods:

• A standard Monark bicycle ergometer was modified by removing the friction belt and attaching 1-6 metal fins to the flywheel.
• Two types of fins with different dimensions but equal surface area were used.
• Oxygen uptake (VO2) was measured, and a predictive formula was derived based on the number of fins (n) and pedaling speed (rpm).

Main Results:

• A predictive equation for oxygen uptake was established: VO2 = a(rpm)b + 0.25 L/min, with derived coefficients for 'a' and 'b' based on the number of fins (n).
• The correlation coefficient between measured and predicted VO2 was high (r = 0.98).
• A preferred pedaling speed range of 29-40 rpm was identified for maintaining constant speed up to 1 hour.

Conclusions:

• The modified bicycle ergometer provides a simple and effective method for underwater exercise.
• The ergometer allows for biological calibration and accommodates a wide range of exercise oxygen uptakes.
• This modification offers advantages such as dual land/water use and extended exercise duration compared to other ergometer modifications.