Finding your potential with VO2max testing

Competitive sport is all about pushing yourself to find your maximum, both in racing and training. Often, the first step in this process is determining your fitness potential. This requires a benchmark, or scale on which to place the athlete. Since the late 1960’s, VO₂max has been one of the primary methods to measure fitness potential. Since its conception, it has been used more and more widely as a training tool.

VO₂max is a measurement of how much oxygen you can consume in one minute relative to your body weight, milliliters oxygen per kilogram body weight per minute (ml/kg/min)

Achieving a high VO₂max consists of a combination of 3 systems: Pulmonary, Cardiovascular, Muscular,

Pulmonary function, movement of air (oxygen) in and out of the lungs

Muscle mass/ fiber type. Aerobic enzyme activities are higher in slow (Type I) compared with fast twitch (Type II) fibers.

Cardiac output: stoke volume, heart rate, peripheral resistance.

Finding out how much oxygen you can take in during a minute gives you a great idea of the potential for performance. Other factors affecting VO₂max are age, gender and body composition.

Age

• After age 25 its all down-hill (VO2 max declines at a rate of 1% per year after age 25)

Average VO2 max in males

• 18-25y 43-46
• 36-45y 35-39
• 46-55y 32-34
• >65y 25-28

Average VO2 max in females

• 18-25y 39-41
• 36-45y 31-33
• 46-55y 28-30
• >65y 22-24

Body composition

•  Body size and composition since vo2max is expressed relative to bodyweight any variation in body weight will affect VO2max.
• Athletes with a large body mass (even if its lean body mass) tend to have lower VO2max than smaller athletes.
• Body composition is also known to influence VO2max – an athlete with a higher % body fat will tend to have a lower VO2max than a similarly sized athlete with a lower % body fat.
• Mode of exercise, highest values are generally found during treadmill exercise, lowest on bicycle ergometer test; specificity is very important
• Muscle fiber type, slow oxidative fibers = highest oxygen consumption

Gender

• Even among trained endurance athletes, the sex difference for VO2 max = 15-20% mainly due to differences in:
• Differences in body composition (higher % lean mass)
• Hemoglobin (oxygen-carrying red pigment of the red blood corpuscles) concentration.
• Equivalent hemoglobin levels are 35-47% for women and 42-52% for men.
• Because hemoglobin requires Iron to carry oxygen, dietary Iron is important for oxygen transportation, lower hemoglobin in woman is one reason for the difference in V02max.

What is a VO₂max test lab test?

• The laboratory VO₂max test employs exercise in a mode that uses a large fraction of the muscle mass such as treadmill, cycling or rowing.
• Exercise progresses in timed stages from light to heavy, until the athlete’s cardio respiratory limit is reached.
• The measurement of oxygen uptake is measured via exhaled gages for volume, oxygen and carbon dioxide, which requires a metabolic cart.
• The maximal oxygen uptake (VO₂max) is the highest level of oxygen attained during exhaustive exercise.

Why test your VO₂max test?

• A measure of cardio respiratory endurance gives an indication of the individual’s aerobic fitness.
• Endurance athletes generally have a larger capacity for aerobic energy transfer.
• Most exercise physiologists believe that VO₂max is the single best indicator of physical fitness because achievement of a high VO₂max is only possible when both the cardiac output and muscle aerobic capacity are high.
• VO2 max is a key component to success in prolonged exercise activities (Bassett & Howley 2000)