This study, published in 1970, is widely considered the first scientific report of exercise dependence. Since then, numerous studies have shown that for regular exercisers, missing a single workout can lead to anxiety and irritability. Three days without exercise induces symptoms of depression, and one week of abstinence can produce severe mood disturbances and insomnia. Hungarian exercise scientist Attila Szabo declared longer experiments in exercise deprivation “hopeless.” Even if you could recruit participants, he argued, dedicated exercisers would, like addicts, cheat and lie about it.
