VO2 Max: Maximal Oxygen Consumption

• Maximal oxygen consumption (VO2max) defines the max volume of oxygen consumed during intense exercise.
• VO2max is expressed as a rate in liters per minute (L/min) or relative to body weight in milliliters per kilogram of body weight per minute (ml/kg/min)
• VO2max reveals information about aerobic system capacity because it requires integration of the ventilatory, cardiovascular, and neuromuscular systems.
• VO2max testing compares performance estimates of aerobic capacity and endurance fitness capabilities.
• A higher maximal oxygen consumption equates to a greater amount and intensity of aerobic work that one can perform.
• Measuring VO2max directly can be time-consuming, requires expensive equipment, and considerable motivation.
• Exercise tests predict maximal oxygen consumption from submaximal performances.
• Submaximal tests predict VO2max from exercise heart rates and work performance.
• Heart rate and oxygen uptake show a linear relationship for light to moderately heavy exercise.
• The PWC170 bicycle ergometer test and the Åstrand bicycle ergometer test represent submaximal aerobic power tests.
• Steady state heart rate is when the rate of work is held constant at a submaximal intensity and heart rate increases until it reaches a plateau.
• When heart rate plateaus, it becomes optimal for meeting demands placed on the body at a rate of work.
• By plotting steady state heart rates on a graph to an assumed maximum heart rate or by estimating VO2max from tables utilizing heart rate and workload obtained at the end of steady state exercise provides allows for the estimation of VO2max using steady state heart rates at given work load intensities.
• Those with a better cardiorespiratory endurance capacity will have a lower steady state heart rate at a specific given exercise workload.

Purpose

• Predicting maximal oxygen consumption (PWC170 bicycle test) utilizing a submaximal heart rate exercise test.
• Predicting maximal oxygen consumption (Åstrand bicycle ergometer test) utilizing a submaximal heart rate exercise test.
• Measuring blood pressure during submaximal bicycle ergometer tests.

Equipment for Bike Tests

• Weigh scale
• Bicycle ergometer
• Metronome
• Ruler
• Blood pressure cuff and stethoscope
• Stopwatch or timer
• Calculator

PWC170 Bike Test Protocol

• Conducted with a partner, blood pressure readings must be accurate before the bike tests.
• Weigh the subject and record body weight to the nearest 0.1 kg.
• The subject is set up on the bike, adjusting handle bars and seat and their resting heart rate and blood pressure recorded after sitting quietly the bike for 2 minutes.
• The subject pedals at 60 RPM.
• The computer may vary for RPM on different bikes.
• Metronome is set to 120, which is equivalent to 60 RPM on some bike computers and 120 RPM on others.
• During warm up phase, the subject cycles for 2 minutes at a workload of 0.5 kp (30 Watts) on the manually adjusted bike or 1.0 kg (60 Watts) on the bike with a basket.
• Heart rate and blood pressure are measured and recorded.
• Following the 2 minute warm up, the subject pedals continuously for 12 minutes according to the heart rate.
• During the first four minutes, the workload is adjusted to achieve a heart rate of 115 to 130 beats/minute at a workload (WL ~ 0.75 to 1.5 kp or 45 to 88 Watts).
• From 4 to 8 minutes, the workload is adjusted to achieve a heart rate of 140 to 155 beats/minute at a work load of (WL ~ 1.5 to 2.5 kp or 88 to 148 Watts).
• From 8 to 12 minutes, the workload is adjusted to achieve a HR of 160 to 180 beats/minute (WL ~ 2.0 to 3.0 kp or 118 to 177 Watts)
• The heart rate, blood pressure, and workloads are recorded for each 4-minute interval on a table.
• Heart rate vs. workload is plotted at the 3 stages of exercise on the graph and drawing a line of best fit, the line extrapolated to a heart rate of 170 beats/min is graphed.
• The vertical line is drawn down from 170 beats/minute to VO2 (L/min) and is recorded on the table
• Following the exercise test, the subject cycles for 2 minutes for an active cool-down recovery phase with no workload on the bike.
• After the recovery phase, the subject's heart rate and blood pressure is recorded.
• Lastly, the subject rests for 3 minutes (no cycling). Measure the subject's heart rate and blood pressure and record the values.

Astrand Bicycle Ergometer Submaximal Bike Test Protocol

• Weigh the subject and record body weight to the nearest 0.1 kg.
• The subject's age and gender is recorded.
• The subject is set up on the cycle ergometer and their resting heart rate and blood pressure are measured.
• The metronome is set to 100 which equals 50 RPM.
• The subject cycles at 50 RPM which is indicated on the computer panel of the bike.
• The subject cycles for 2 minutes at a workload of 0.5 kp (25 Watts) on the manually adjusted bike or 1.0 kg (50 Watts) on the bike with a basket for a warm.
• Heart rate and blood pressure are then recorded during the 2 minute warm up phase.
• Then the workload on the bike is adjusted every minute until the subject's heart rate reaches 130 beats/minute ensuring the workload is adjusted at 0.5 kp intervals.
• Heart rate is measured in the last 10 seconds of every one minute interval.
• Blood pressure is measured at the start of each 2 minute interval but blood pressure value is entered as a 3 minute BP.
• After this heart rate and BP is recorded.
• Once the subject's heart rate reaches 130 beats/minute, the workload is to kept constant on the bike for 6 minutes.
• If the heart rate decreases below 130 beats/minute, the workload is increased by 0.5 kp or 25 Watts.
• The heart rate should increase above 130 beats/minute until a steady state is reached, but should not be higher than 170 beats/minute.
• The test can terminated once heart rate has reached a steady state and results in the same heart rate value for the 5th and 6th minutes within 5 beats/min for the 5th and 6th minute.
• After the exercise test, the subject cycles at 0.5 kg (25 Watts) for 2 minutes for a recovery phase.
• Their heart rate and blood pressure are recorded during this recovery phase.
• The subject rests for 3 minutes (no cycling).
• Their heart rate and blood pressure values are measured and recorded.