I utilize 20-minute workouts all the time. The whole time that I was in Cali, I only did 20 minute workouts.
Matter of fact, while I was traveling, I only was able to fit in 6 training sessions total. I averaged about 2 per week, and did a
bunch of walking. My friends and I made the best of what we could do with the time and resources that we had available.
Never let perfect be the enemy of good.
The coolest thing ever was getting to work out at Gold's Gym in Venice Beach, Cali. It's the Mecca of Bodybuilding. It's the home of the
first Golds Gym, also where Arnold Schwarzenegger did a lot of his training in his hay day, plus many more famous bodybuilders.