Mononucleosis is a viral illness that can linger for weeks, months or even years. It has earned the nickname of the "kissing disease" because it can get passed from one person to another through saliva.

Mono is also known by glandular fever.
The athletes intensity in training and traveling do damages to the body, immune system, energy levels, the fitness of muscles, ligaments, and tendons.

If they suddenly develop a cold, fever, sore throat or stomach issues, it's vital to rest instead of continuing to train and to compete.