“2. It reduces muscle tension. Exercise serves as a circuit breaker just like beta-blockers, interrupting the negative feedback loop from the body to the brain that heightens anxiety. Back in 1982 a researcher named Herbert de Vries conducted a study showing that people with anxiety have overactive electrical patterns in their muscle spindles and that exercise reduced that tension (just as beta-blockers do). He called it the “tranquilizing effects of exercise.” Reducing muscle tension, he found, reduced the feeling of anxiety, which, as I’ve explained, is important to extinguishing not just the state but the trait of anxiety.”