Things like this always kind of bother me. It is like folks are framing a question to get an answer they want. “What is the best gun if I do not want to spend a lot of money but want something super reliable and also really cool?” or “What is the best bolt action rifle that costs less than $120 has dirt cheap ammo and was manufactured between about 1898 and 1945 in a country that borders Poland and China?” Maybe even worse folks ask for seriously sub optimal and almost ridiculous advice like “So I won’t exercise at all and will continue being a huge slob, also I am not willing to spend any money or time on preparedness, have no extra space in my home and am unwilling to change my current lifestyle in any way but how do I become completely prepared for the Zombie apocalypse in 30 days?”

For folks getting back into fitness the key is to start with something that is reasonably easy (in fancy words training OPTIMALLY not MAXIMALLY) and to slowly but CONSISTENTLY  and methodically progress in difficulty and length of effort based on some reasonably logical plan. Heck, those are the keys to fitness anyway but older folks with some extra pounds and maybe some injuries can’t get away with what healthy 22 year olds can.
Tighten up on your diet is so important I just can’t talk about it enough. Like a lot of things as you get older the slack goes away. At 20 or 25 most folks can eat just about anything and stay at a healthy weight but that goes away over time. I am not saying that you have to shift to a perfectly healthy diet tomorrrow but just about everybody can do better. Have a bit of discipline to not eat complete junk like fast food, chips and sweets all the time and pay some attention to your portions. A significant amount of the “bad knees/ hips/ backs” of 35-55 year olds would magically be cured by getting to a reasonable body weight.
Assuming a program makes some sense ie: is progressive or scalable, allows enough time to recover, has strength, muscular endurance and running/ rucking type components and generally passes the common sense test it should be just fine. Doing something is probably more important than following the perfect program.
As to specific points that came up in this series with my comments:

“To start with, use only a few primitive techniques (punches, kicks, blocks, movements) and combinations of them. A simple well-practiced technique is far better than several of those which you won’t be able to do in the critical situation. A simple and reliable technique is far more valuable than a complex one.”

I agree with this but it kind of misses a simple and valuable point. The basics are what make you a good athlete or fighter. It is honestly a disservice to call them the basics in that it demeans them and implies that there are some more useful and advanced techniques out there. The difference between a total novice and a great fighter or shooter is that a great fighter or shooter can properly apply the basics very quickly at the right time with a high level of consistency while a novice fails at some or maybe even all of those.

For example anyone could learn in an afternoon the exact same skills that Chris Costa of Magpul fame or genuine Tier 1 Bad Mama Jamma Larry Vickers use to draw and fire a handgun. Does this mean that they would be able to put a round downrange from concealed carry in the same sort of time, let alone have the same accuracy? Does it mean that Mr. Couch Commando could defend himself as efficiently as either of those gentlemen could if he was attacked leaving the Bank after cashing a check? I seriously doubt it.
If you can’t do at least 50 push-ups in a single set, your punch will never be any good.”

This is just stupid and is really what bothered me enought to write this whole thing in the first place. First of all let us look at where striking “power” comes from, namely proper technique and then sheer strength.

I have been hit by a lot of people in my life. Some of them were professional fighters. A professional welterweight outpunched a few 220+ pound big strong men because he really knew exactly what he was doing. Bringing us back to the first point for a second this is a great example of mastering the basics. Secondly if we factor it out technique by getting fighters of similar skill levels then sheer raw strength (and size but those two usually rhyme) is what matters in terms of striking power. A punch is a quick aggressive movement of near full force. If you are going to exercise to hit hard you lift big heavy things to get stronger, period. Local muscular endurance, which is what max rep pushups measure has absolutely nothing to do with this other than that it may be losely related to strength.A guy who is strong (we would have to define that but I don’t feel like tossing out some random arbitrary numbers) can hit hard, a guy who is REALLY STRONG can hit REALLY HARD.  Jim Wendler or Matt Kroc could hypothetically have the fighting technique of an average elementary school kid and still hit REALLY HARD because they are just that strong.
Lastly to utterly refute this concept I bring up Butterbean. I rather doubt he could do 50 good pushups but he sure hits hard.

In a reply to this post a fellow recommends training in some Japanese swordfighting thing called Kendo to get into shape. This sounds like a great plan if you want to learn traditional Japanese swordfighting but is a poor allocation of precious time and money if you want to get into shape or learn an effective modern martial art to defend yourself with. It honestly seems sort of like apprenticing yourself to a buggy whip manufacturer.
Well, those are my thoughts on that.