There are different aspects of physical fitness and each contributes to overall fitness in either a positive or negative way.
CRE is the ability of the heart and lungs to work efficiently together to provide the working muscles with oxygenated blood for a prolonged period of time.
This allows a performer to maintain the same pace throughout a long period of play. Someone with a higher level of CRE will not tire as quickly, and so quality of movements and skills are maintained until the end of the performance.
High levels of CRE help a footballer move around the pitch at a competitive speed and also perform important skills such as passing, tackling and shooting with more accuracy and chance of success until the end of the match.
A gymnast performing a floor routine with high levels of CRE will be able to perform movement skills such as tumbling, balancing, leaps sequences and dance with more control, quality and fluency. This will demonstrate greater skill and complexity of performance and likely result in a higher score.
How might high levels of CRE have a positive impact on a triathlete?
A triathlete with high levels of CRE will be able to maintain good speed and form over all three disciplines for the full duration of the race. This gives them much more chance of a faster time and a higher position.
In hockey a player with low levels of CRE will struggle to move up and down the pitch quickly enough, especially towards the end of a game. This will mean they cannot perform their role for the team such as marking an opponent (which could result in the opposing team scoring), providing an opportunity for a pass or being in the correct place for a set piece (which could reduce the number of scoring opportunities).
A dancer with low levels of CRE may struggle to maintain control, balance, fluency and timing of the movements nearer the end of a routine. This will directly affect the score they are awarded.
How might low levels of CRE have a negative impact on a tennis player?
In tennis, low levels of CRE mean a player will not be able to cover the court quickly enough to get return shots back over the net, especially towards the end of games and sets. Being slightly out of position will then affect the accuracy of shots, resulting in more mistakes and fewer points won.