Athletes tend to have lower resting heart rates and greater resting stroke volume due to heart muscle hypertrophy than 

non-athletes. Aerobic capacity measured by maximal oxygen uptake (VO2 max) is regarded as the most reliable indicator of cardiorespiratory and overall physical fitness.

Having a significant aerobic capacity is a crucial component of athletic success and affects one’s performance on the field. Obtaining this fitness reduces the metabolic demands of the cardiac muscle related to the activity, which spares the heart from undue exertion and helps increase cardiac output when needed.

Exercise-increased vascularization of the skeletal muscles causes the capillaries to become more dense heightening the

ability to irrigate the muscles with blood.  Mitochondria, the main energy supplier, fundamental for the processes of sustaining body activity during exercise and considered the “powerhouses” of muscle cells are increased with activity, generating the ATP required for muscle contraction.

Sport physiologists regard VO2 max as one of the most reliable indicators of an athlete‘s overall physical fitness. Of course age, gender, genetics, prior training, body composition, physical state, testing procedure and more all affect results of the measurement.

Conditioning programs can effectively optimize aerobic fitness and sport-specific performance. Measurement of aerobic capacity can be thought of as twofold: not only does the athlete get a view of where his or her fitness is relative to themselves but the coach has an opportunity to evaluate their own program related to individual progress.

Maximum oxygen uptake can be measured numerous ways.

The most accurate is a graded exercise test using indirect  

calorimetry wearing a mask, which records oxygen consumption and carbon dioxide production. This can be done on a treadmill or stationary bike. There is also the Cooper 12-minute run/walk test, multistage shuttle run (beep test), wearable fitness devices and other products that companies put forth.

The key to measurement and most importantly is consultation with your medical staff and athletic trainers before administering testing. Then using the results in a positive manner to provide information to the athlete and evaluate one’s own fitness program. A great way to Get fit and Strong.