I just had another calf injury a couple of weeks ago. I am turning 60 this month. I want to keep trainning and practicing my forms, up to and including Koryo. I have been trainning with 54 year old folks and younger. I love the school, and I am very comfortable with my TKD family, but my body just cannot take a beating anymore. I need to train at my pace. I have been feeling like a good bad example at the school. Any routines you recommend for at-home trainning? Thank you!
I would see a cardiologist and your own doctor, since each person might have unique things that you might not have mentioned, but which are important to consider. For example, do you have arthritis, plantar faciitis, heart or breathing problems, etc.
But if you are in generally good health, and doc says it's okay, then the best you can do is maintain a daily regimen of aerobic (not anaerobic) cardio exercises - so daily brisk walking, with periodic changeups to biking, swimming, hiking, or whatever the season allows for.
I would recommend taking one day out of a month (or more, if you can spare the time) and take a hike along some wooded trails - quiet, peaceful, and spiritually healthful, and take along a book, particularly one which relates to your style, and read it during the rest stops.
Meanwhile, make some changes in your overall lifestyle, if you haven't done that already. For instance, take up classes in tai chi or yoga. Join a gym, like a YMCA. Learn how to make - and thrive - on juiced or blended meals or otherwise get creative on making healthy meals. Participate in a community group which supports that kind of lifestyle - like a senior's walking group (not that you're senior - but you might have the skills to lead them). You might volunteer with community events which help to get the blood circulating and the lungs pumping. So, join an active Elk's lodge, church group, community clean up group, auxilliary police or firemen's group, join the EMT squad, and so on. What this does is inject an active daily routine in your life, without you having to do that - which is a common reason why exercise regimens fail - people get bored and lost interest or don't have the means or ideas to change things up.
Are they TKD routines? Well... yes and no.
These are things which are necessary for overall health, which contributes to your success in the dojang. Often, I see people doing things like forms in their basement - but few people can maintain that for more than a few weeks. It's easy to learn the movements in a form, you can do that in a day or two. What you can do at home is to polish it up, but without an instructor with you, bad habits could settle in, so unless you head to the dojang several times a week, that might not be the best advice.
If you are well-versed in your poomsae, as I suspect since you indicate you know Koryo, you might change up your forms so that you introduce dynamic tension, slow breathing exercises, or exaggerated movements for the purpose of stretching.
If you have the means, get a kicking bag. Either a free-standing or a free-hanging bag, or mount a kicking pad to a wall. Whatever works for you.
If you want, buy a couple of rebreakable boards, line them up on stacked cinder blocks, and practice some breaking techniques for conditioning. Along these lines, join a breaking club, like US and World Breaking Association.
You might even have a friend who takes up another style of martial arts; in this case, exchange ideas - see what is similar, see what is different between your styles.
Do try to research seminars - any style - and attend them.
The idea is to get a flood of ideas of things to do, mostly to ward off boredom, but also so that you have things you can do if you are injured and can't train.
Again, with doctor's okay, get books on stretching. My favorite is "Secrets of Stretching" and "Scientific Stretching" by Tom Kurz (Stadion Books). Many Taekwondo schools focus a lot on stretching, a curse for us older folks when training in a school of young kids, whom you may think view us as old curmudgeons slowing down the class. While that is not your problem - that's something that those kids have to deal with as well as the instructor - that instills no confidence in you.
Along these lines of books (Stadion also has DVDs which I recommend), you may find that the YouTube channel of Elastic Steel may be more suitable to your lifestyle. The videos can be haphazard if you don't know where to start, but, if you have the time and patience, that would be an excellent way to get ideas on maintaining your flexibility.