[weatherlite]

Its possible your max HR is way above your age (the 220 - age thing is really inaccurate). You can buy a chest strap / get properly tested to find out. I would try to make at least some of the workouts a bit more challenging - you can try pick up running. Or if you're working the stairs machine, do it faster and for longer for at least part of the time. This will not only make it more interesting for you - its also the only way to improve your vO2 max if all you're doing is 3 workouts a week (and a higher v02 max should be your goal is you're thinking about longevity / health). As for energy levels - I meant in general. After hard workouts I can be quite exhausted for 24 hours sometimes. That's normal. But my sleep is usually higher quality and the day after I'm a bit more vital. My mood is more stabilized etc.

Anyway good luck! I hope you'll take away from this that its OK to change /mix things up and see what works for you.