I've found 7 interval workouts that independently target endurance, muscular strength, and speed. For variety's sake, is it ok to move these around week to week or is it a rule to keep it the same all the time? For example, always do them on Tuesdays and Thursdays but swap Tempo and Lactate Threshold from T to Th every other week? Additionally, is ok to use up all 7 types over the course of a month, plugging them in here and there (obviously avoiding doing similar ones like Lactate and Muscular in the same week). Thoughts?

It might matter if your entire life is scheduled so regularly. Some folks can manage that. They wake the same time every day, plan every meal, poop at the same time every day, same work schedule, bed at the same time. Anything that throws off their preferred schedules might hinder their training and performance.

My life is so erratic and unpredictable I don't plan or schedule anything, other than medical appointments for a family member I take care of. I don't even remember what any sort of schedule or routine was like, although having been in the military and federal gummint employee for years I seem to have a vague recollection of that life.

• I do interval training once a week, roughly midweek. Maybe Tuesday, maybe Wednesday (which I did, Wednesday this week), maybe Thursday. Back in the summer I was doing interval training 2-3 times a week and burned myself out by September, when I took a rest and rode much more casually for a month to recover.
• An FTP ride for about 90-120 minutes (including warm up and cool down) once a week, usually with a rest day after the HIIT day. (Planning on that this morning with a friend who's stronger and faster to push me out of my comfort zone.)
• Then a long solo ride on the weekend at a pace I can sustain without needing a long rest break midway.

Not ideal but it works well enough that I've had significant gains in fitness since June when I began more or less methodical training. Before then I just rode whatever casual rides I could fit in, riding more often and more miles but not improving in fitness. My average speed over distances of 20-60 miles has increased from 12 mph in May to almost 16 mph now. Not impressive for most folks, but considering my limited respiratory capacity (lifetime of respiratory disease, many bouts with pneumonia, etc.), other health problems and age (60), I'm pleased to see any measurable gains.

I'm no guru on any of this so this is just one opinion. I would think that so long as you give sufficient recovery time for each muscle group, but not so much rest time that they start losing their fitness, you should be fine to rearrange things in ways that make sense to you. On the other hand, if you're targeting the same muscle groups but with different desired effects, it may be trickier to do that. For instance, I wouldn't think it was wise to target the legs for muscle strength one day and then go out to work on speed the next day.

To be entirely honest, my gut feeling is that you're trying to juggle too much at once. You might be better off focusing on just one or two of those things at a time and seeing real improvement there, rather than try to do everything all at once and not get enough of anything, allowing for sufficient recovery, to really see the improvements.

Thanks, guys. I'm limited on time and of course stuff changes in my schedule all the time. BTW, I'm 57 and am trying to get organized so I'm doing the hard work midweek, like on T and Th so I can have a hard ride or race Sat or Sun.

You want to ride hard intervals when you're freshest; ex VO2Max Mondays following your Sunday day of rest.

Tempo "intervals" aren't hard enough to improve FTP, are too hard to improve your aerobic threshold for long rides, and aren't hard enough to require rest. If you want time at tempo, just ride 1x60 minutes or 1x90.