OK, so I have three women in my life.... two daughters and a wife. As such, developing any kind of routine is (quite simply) impossible. They don't have one and don't want one. They will never have one and I can't force it. Being that they don't have one, and we all cohabitate, I will never have one either. "Get to the point, Twofer!!!!!" OK, fine. I have found a dozen or more apps designed for people like me. Some literally let you type in how many minutes you have to work out. And it will lay out quick workouts.... most involving little or no equipment.... that allow you to squeeze in what you can when you can. They usually include squats, planks, mountain climbers, pushups, etc. I have an exercise ball, kettlebell, elliptical machine, jump rope, resistance bands, etc. at home. But I can sometimes squeeze in a short workout at lunch at work. 1) Have you used, and can you recommend, an app? 2) If not an app, how about a web site that shows various quick workouts I can print out? Discuss quick workouts using little or no equipment that one can do anywhere. Go.
I weight lift and use wendler 531. For quick workouts I use bodybuilder.com. They are a great resource for different type's of routines.
I simply do a max out set once a day of Spider-Man push ups, alternate knee to elbow sit ups, and pull ups. I have a pressure-bar in one of my doorways for the pull ups. IIRC I'm almost your exact age, ill be 47 in october. I'm in 30 waist, have well defined abs, pecs and biceps. This little maybe 10 minutes a day seems to be working. I eat nothing special, with little to no restrictions besides I don't do much pop or breads. I smoke, and I sit on my arse a ton. I drink lots of beer. I do a lot of walking for work, and its hot... I cook.... But I only drink water after my first coffee for the rest of the work day.
I like cycling HIIT videos on YouTube. I found a channel that has them in varying lengths. I'm sure there's something similar for other pursuits also.
For Android, I have used 30 Day Fit Challenges Workout and Spartan Body Weight Home Workouts. They are both free, but have in app purchases and ads. I never noticed the ads to be intrusive when I used either app. The 30 day one I like since it doesn't let you move to the next exercise until you complete the current one. Sure, you can cheat and say you did it, but you're only hurting yourself by cheating. -Mike