Study shows exercise, substance abuse link

Researchers at Brookhaven National Laboratory have found in experiments that daily physical exercise decreased adolescent rats' appetite for cocaine, a development they said indicates such activity may protect against cocaine abuse later in life.

"This is a first step in trying to understand the connection between exercise and substance abuse," said Panayotis Thanos, a neuroscientist at Brookhaven lab and the National Institute on Alcohol Abuse and Alcoholism.

He is the lead author of the study to be published in the latest 2010 issue of Behavioral Brain Research and available online Wednesday.

The study led by Thanos explored how exercise during adolescence affected later drug use.

"Adolescence is an important developmental stage where exercise plays a key role in both brain development and brain chemistry," Thanos said in a statement. "Adolescent and young adult animals are also more susceptible to drug abuse," he added.

The experiment used sedentary rats as control subjects, while the exercise rats ran on a treadmill five days a week over a six-week period.

The animals had been trained to expect cocaine in a given environment and then tested to see if they preferred that environment to another where they hadn't received the drug.

The exercising male rats had no significant attachment to the cocaine environment, indicating they had been protected from forming a strong attachment to the cocaine, the study found.

Among exercising female rats, there was still some attachment to the cocaine environment, but "significantly less" than the non-exercising female rats.

Previous studies have also suggested a link between exercise and the prevention of substance abuse.

Among them, a 2008 rat study, led by Mark A. Smith of Davidson College in North Carolina, found exercise reduced the "rewarding effects of cocaine."

Smith, in an interview Wednesday, said the scientific literature is full of studies that show people who exercise more tended to use drugs less.

With his study and the Brookhaven lab study, he said, "Here, we're starting to see the first evidence that exercise has a cause-and-effect relationship on decreasing drug seeking [and] drug taking behavior."