Press cutting: Fit adults produce fewer stress-related chemicals

The two chemicals measured were interleukin-6, or IL-6, and tumor necrosis factor-alpha, or TNF. …

Stressed but fit middle-aged adults produce far less of the two chemicals and have less inflammation than couch potatoes, said Dr Mark Hamer [UCL Epidemiology & Public Health]. …

Hamer tested 186 healthy adults who used exercise bikes. He drew their blood, gave them two mentally stressful exercises and then drew blood again. The mental stress should release a surge of the two chemicals. "It's a normal biological process, gearing up for challenge," Hamer said.

The least fit had five times the increase in TNF as the most fit. The fittest adults also had one-third of the increase in IL-6 found in the blood of unfit adults.

That means mental stress probably is doing less damage to the fittest adults' hearts, he said. …

Marilyn Elias, 'USA Today'