For fitness tests to be comparable, the tests are often not sport-specific, this may mean that the benefits to the sportsperson are restricted
It may also mean that the conclusions drawn about that individual's fitness are not wholly representative
Fitness tests are generalised so they do not replicate movements of activity and do not always indicate an individual's proficiency in certain movements or sports
Sports participation often involves unique conditions which cannot be replicated accurately in a fitness test
if a fitness test is measuring a fitness component which is not a maximal reading, then it will affect the reliability
Some readings may be affected by motivational factors: an individual's motivation may be influenced by the knowledge that they are completing a test
To make valid measurements, fitness tests must be standardised and all follow the exact same procedure
Tests carried out without this in mind will not be comparable to averages for the same fitness component and this will affect the validity