An office worker is experiencing chronic stress from a high-pressure job, leading to fatigue and irritability. They decide to start exercising to improve their well-being. Friend A suggests they do high-intensity sprints for 15 minutes only on days they feel extremely stressed. Friend B suggests they incorporate a 30-minute brisk walk or jog into their routine 3-4 times per week, regardless of their daily stress level. Based on the principles of building long-term resilience, which friend's advi