My boxing workout plan - Tips for Fritz
I branched off @DrFritzS's post and have some advice. I did some (kick)boxing in my 20s and I've been a general martial arts enthusiast my whole life. I have a heavy bag in my basement (currently gathering dust but I'd like to get some use out of it). Here's what I can advise.
1. Warm-up your joints
Your workout should have a warm-up anyway but if you're in your late 40s, you might need longer to get the joints well lubricated. See #2
2. Take Care of Your Shoulders
People who work on computers have shoulder problems (e.g. shoulder impingement) often. Hitting things (bags, pads) very hard is high-impact on these areas so extra care to warm up, stretch, ice, whatever it takes to keep these from malfunctioning and ruining your ability to keep training.
3. Tips for Skipping Rope
Once you master it, you have a great source of cardio that is very efficient (burns twice as many calories as running per minute), fun and looks cool. Getting started is hard if your only background in skipping is the schoolyard. In the schoolyard, kids tend to double-bounce between skips, but that won't let you get faster or do any alternate kinds of steps. Start slow and don't double bounce between skips - when you hit the ground stay still until the next time the rope comes around.
4. Ensure Respect and Safety
If you spar, be sure to walk away from anyone who isn't willing to practice at the same level. Macho dirtbags who want to prove their superiority can injure you and derail your training and progress.
5. Have Fun
The best exercise is one you enjoy doing. Find occasions to smile as much as possible during the workout - boxing and martial arts can be silly in today's modern world and not taking things too seriously, and keeping things light is a way to keep the enjoyment level high.