However, performance of very strenuous, repetitive, unaccustomed exercise will exacerbate muscle damage. Also, in a competitive event, the zeal to win or shame of quitting may allow some individuals to go beyond a tolerable level of muscle injury. Other factors that may be involved are the presence of cold or flu-like symptoms, abrupt changes in diet or use of ergogenic aids. A common feature in those cases where renal failure has occurred is that the ambient temperatures were generally high and many of the individuals appeared to suffer from heat stress, characterized by either profuse sweating or heat stroke. Some individuals may be more susceptible to heat stress.
Susceptibility is influenced by the state of dehydration as well as the state of acclimatization.
Also, there may be a subclinical latent muscle disorder that would predispose certain individuals to heat stress and rhabdomyolysis. It also can occur after strenuous recreational activities such as marathon running and hiking, or performance of excessive strenuous exercise during the first days of a new training program. Although mild cases of rhabdomyolysis do not require hospitalization and individuals recover within one week, the condition can be severe in certain individuals. Added heat stress can produce acute renal failure, which, in rare instances, can result in death. Some individuals may have a latent, subclinical muscle disorder that predisposes them to the most negative consequences of rhabdomyolysis.