Pain occurs with potential or actual tissue damage, so it is a warning sign. There are different types of pain, which relate to the duration rather than intensity of pain felt.
This type of happens immediately after an injury. If there has been tissue damage there is likely to be some swelling due to the inflammatory process. The degree of swelling and ability of the injured limb to function can be a good indicator of the level of injury. A significant injury e.g. a fracture or severe ligament injury will normally prevent you from continuing to play. Acute pain is short lived lasting for a few hours up to several weeks depending on the degree of damage.
This is a more persistent pain that may not have a specific injury. The most common example in sports is Tendinopathy. The symptoms are mild initially and will gradually worsen without rest. This is because the healing process is faulty, so it is unlikely to resolve without specific sports therapy treatment. Chronic pain may also be an indicator of more serious damage, or it may occur because of a problem with the pain mechanism. The pain process itself can sometimes be self-fulfilling when the initial injury has resolved. This is because pain is a complex interaction between physical, psychological and environmental factors.
The golden rule if you do experience pain from training is that it should not last longer than the time you spent exercising and you should not develop latent pain (i.e. pain a while after you have finished exercising). If you have any concerns about whether to continue training then contact the Optimal Sports Therapy Centre for advice.