Science says that a vigorous 30-min workout can buffer your body against stress, lowering cortisol, and speeding recovery more than lighter exercise, health minister Dr Sabin Nsanzimana tweeted recently. If you are heading into a stressful event, a tough workout beforehand might help you cope better, he noted. EXERCISE and STRESS: Science says:a vigorous 30-min workout can buffer your body against stress, lowering cortisol,speeding recovery more than lighter exercise If you’re heading into a stressful event,a tough workout beforehand might help you cope betterhttps://t.co/PwPIWjMJKF pic.twitter.com/acKhB2nVbq — Dr Sabin Nsanzimana (@nsanzimanasabin) December 7, 2025 The minister then also shared research from a study titled, “The effects of exercise intensity on the cortisol response to a subsequent acute psychosocial stressor.” ALSO READ: Calming techniques to relieve anxiety The study published in “Psychoneuroendocrinology” found that the intensity of a single 30-minute exercise session can influence the body’s hormonal response, measured through salivary cortisol, to a subsequent acute psychosocial stressor, with vigorous exercise reducing this stress response. ALSO READ: Chronic stress linked to higher stroke risk, women more affected – study Researchers assessed 83 healthy young men who were randomly assigned to 30 minutes of light, moderate, or vigorous treadmill exercise. After a 45-minute rest, all participants were exposed to the Trier Social Stress Test, a standard laboratory method used to induce stress through public speaking and mental arithmetic. Salivary cortisol samples were collected repeatedly throughout the exercise and stress phases to measure activity of the hypothalamic-pituitary-adrenal (HPA) axis, the body’s central stress-response system. According to the study, participants who completed vigorous exercise showed the lowest cortisol reactivity to the stress task. They registered reduced total cortisol output, a smaller spike in response to stress, and faster return to baseline levels compared with the moderate and light exercise groups. The researchers found an inverse relationship between the cortisol released during exercise and the later response to stress. People who showed higher cortisol levels during the workout tended to show a reduced cortisol response during the stress test. The authors said the results indicate that the intensity of exercise influences how the HPA axis responds to subsequent stress. They noted that a single bout of vigorous exercise appeared to dull hormonal reactivity more effectively than lower-intensity activity. The study focused on young men, and the authors stated that additional research is needed to determine whether similar effects occur in women or older adults. How exercise can break the cycle of stress Celestin Mutuyimana, a clinical psychotherapist and researcher, noted that intense physical exercise has frequently shown results in his clinical work with people living under constant stress. “When the exercise is intense, running, intervals, heavy resistance, the body reacts immediately. Stress hormones rise for a short time, then drop. That drop is what helps the nervous system stabilise,” he said. According to Mutuyimana, vigorous exercise keeps the mind fully engaged, pushing aside negative thoughts and emotional tension. During intense workouts, the focus shifts entirely to the effort, making it difficult for anger, frustration, or stress to take hold. “People under pressure often forget tasks and lose focus, which only worsens their stress, but after regular intense workouts, the mind clears, planning improves, and the body finally relaxes,” he said. Mutuyimana explained that prolonged stress can take a visible toll, especially for those facing relationship setbacks, trauma, or heavy workloads. For instance, patients neglect their appearance, seem exhausted, and struggle with low self-esteem, adding to the pressure they experience. “Exercise can break the cycle of stress, for example, physical changes like weight loss, improved skin, and increased energy boost confidence, and as people start feeling better about themselves, stress stops dominating their thoughts. “Not all activity has the same effect. Rhythmic aerobic exercises such as brisk walking, cycling, swimming, or jogging reduce stress quickly, while mind–body practices like yoga and tai chi offer short-term calm but may be less effective when stress is severe. For fast relief, intensity matters,” Mutuyimana said. Janvier Muhire, a consultant psychologist and founder of the Baho Well-Being Initiative, a Rwanda-based platform offering psychotherapy and mental health support, noted that aerobic exercises raise the heart rate and trigger endorphins, which improve mood and lower stress. “Mind–body activities, including yoga and tai chi, work differently by combining movement with breathing and focus, helping the nervous system slow down and easing stress-related tension,” he stated. When is it advisable to exercise? The psychotherapist added that exercise can be done in the morning or evening, but what counts is keeping it consistent. He explained that the body’s nervous system responds best to repeated cycles of effort and recovery. But, he said, intense workouts should not stand alone, especially for people with heart conditions. Mutuyimana noted that in therapy, he introduces vigorous exercise only after tackling the root causes of stress, following the Kinyarwanda proverb, “Aho kwica Gitera wakwica ikibimutera”, which loosely means, “Rather than targeting the symptom, tackle the cause.” Muhire said the benefits of exercise can vary depending on the time of day. Some people find that morning workouts help them feel focused and mentally steady as the day begins, while others prefer exercising in the late afternoon or evening as a way to release stress built up from work and daily responsibilities.
