Why don't you look at this and explain to everybody why you're not ignorant? https://www.youtube.com/watch?v=JNvTwyIWs1o You obviously are nothing other than a poser who doesn't even know how to wrap hands. You are providing a good laugh for some trainers and boxers in a boxing gym right now.
No 21 years of age is not too old. My opinion is that your strength program may not be "functional training" for boxing. One thing about the boxing training I did is it was influenced greatly by time. I think the principle behind it is that duration of work, intensity of work and frequency of work are every bit as much elements of functional training as muscles worked and patterns of movement. Sort of like training for sprints and training for a marathon aren't going to be the same. You will most likely be better off training to be strong for 180 seconds and resting 60 seconds than just being powerful for about three or four explosive movements. Think about a boxing contest. What is it? It's not a contest to see who hits hardest. It's competing against an opponent for a certain amount of rounds and as everybody knows a round is typically a 3 minute interval followed by a 1 minute rest period. Boxing is really more of an endurance sport than a strength sport.
I think weight training is good for boxing. BUT so is running. AND the most important thing to do to become a good boxer is boxing. Since you state you have never boxed before I would start out there. The majority of your time spend should be boxing. You can supplement that with weight training and running. Starting out you will need to get used to the strain boxing puts on your body though. If you do it right it should be intense.
Guys, thank you for your opinions. But I want you to read properly - this is general STRENGTH preparation. Conditioning and technique is alright. People who say that having more strength in boxing is useless are plain ignorants.
He's squatting. No wall sit can compete with squatting. They cannot build leg strength in person who already squats regularly.
His routine is solid. Not an in camp routine but a good one to use between camps. Your only goal when lifting should be to get stronger. Not be better conditioned. You read right. Conditioning can be achieved with traditional running and training just fine.
One of the better weight routines I've seen. Couple things: 1. If you haven't lifted before you need to work up to that sort of strength routine. 3x3 is pretty heavy. 2. No mention of your boxing routine. That sort of heavy lifting is going to take recovery and interfere with your gym work A LOT.