Painful a. : Full of pain; causing uneasiness or distress, either physical or mental; afflictive; disquieting; distressing.

Painful a. : Requiring labor or toil; difficult; executed with laborious effort; as a painful service; a painful march.

Painful a. : Painstaking; careful; industrious.

Example:
How do you stop Painful legs while running in a race?

Taxonomy
pain, physical pain, injury, unpleasantness, the brain, body, sensation, nociceptors, animals, dimension, signal, pain and suffering, chronic pain, stimulus, diameter, Theory, affective, duration.

Defination from the web:
painful or painfulness in a broad sense. ... of the body's defense system, triggering mental and physical behavior to end the painful experience. It promotes learning so that repetition of the painful situation will be less likely. ...