I love this question. I love it because it can follow a framework of timing spent on particular types of exercise and intensity for individual goals. As someone who loves to break down how I could progress, I found it compelling to do a math problem with time to formulate my plan. ⏰
I initially subscribed to the practices and results I saw within the realms of physiological development that became a part of my life. In baseball, it's a game of long-form repetition. Take 200 swings to dial in the muscle memory or practice 50 ground balls to develop footwork and body positioning. In weight lifting, alternate body groups for at least 24 hours of rest, get three sets of 10 to 15 for a "good" strain. And in triathlon, log a certain amount of hours or miles in the specific discipline based on your distance of choice. Groove the right amount of time for threshold work, and dial in the aerobic foundation to be a race-ready athlete. The science is there; periodization works. I am definitely oversimplifying these disciplines, and the high-level concepts are easy to follow and still practiced heavily to date.
Once I started to ask myself more profound questions, like what about my longevity? What about a diversely functional body? What if I wanted to endure, enjoy family time, be strong, commune with friends, gain mobility, explore new boundaries, and maintain energy for it all? How I was exercising and the amount of time I spent doing it started to take a different perspective.
Whether it's for me or others, I start with: What do you want from your body in life? Once you know what you are looking for, you can break it down into specific goals. My goals mostly boil down to balanced energy throughout the day and expanding my capabilities physically as far out in life as possible. I want the option to use my body to run a long-distance or pick-up and play with my grandchildren. I want to stay in front of the campfire for hours with my people, talking about our life experiences. It does bring it back to the longevity piece for me. Whether your goals are more big picture or very specific, you can use desired metrics around body composition or personal achievements in performance. My go-to right now is daily HRV and balanced sleep numbers.
So bringing it back to the original question, regardless of where you sit today and your goals, how long should you work out?
Here is the framework I like to follow on timing and intensity.
Do at least a small amount of something moderate every day, even if it's a brisk walk. According to this widely heralded study, one hundred fifty (150) minutes per week or approximately 21 minutes a day is the ideal amount of exercise as a baseline.1 Go to 64 minutes a day and you nearly double the improvement in your mortality rate.
30% of your time working out should be dedicated to higher intensity activities.4
At least two days of the week of resistance (strength-focused sessions) will yield you the best soft tissue development.5