In personal experience as a dedicated rock climber (traveling full time for half of the last 15 years), I can easily conclude that bursts of intense exercise accomplish a lot more for health and fitness than prolonged, more gentle workouts. Intensity readily builds muscle mass and coordinates muscle fibers, while fostering feelings of clarity and joy. It’s just the easier pathway to “being fit.”<p>Climbers train for intensity. One can easily convert high-intensity fitness to low-intensity but prolonged fitness. The other direction does not happen. High-intensity and short-burst fitness is more malleable, capable of becoming any type of fitness. Ie, a climber with bouldering fitness transitioning to sport climbing will take just 2-3 weeks to attain good results, while a sport climber transitioning to bouldering will take at least two months. Boulderers and sport climbers can instantly perform on multi-pitch routes, without a transitional period. The intensity gradient from intense/short to gentle/prolonged is bouldering -> sport climbing -> multi-pitch.<p>However, I have never been at peak climbing fitness without daily walks. The assumption I have always held is that walking resolves problems (much like what sleep accomplishes for tissues, immune responses, emotions, memory, and cognition). You’re walking, blood is flowing, the whole body is coordinated, you’re breathing through your nose, you can think… it’s integrative. Humans are designed to walk.