To all on this forum,
Using a heart rate monitor is REALLY valuable. It gives you a critical safety valve feature to know when you can or should continue, and when not. For best longevity to those pushing their health envelope, as your heart rate slows after a hard interval of any duration, it should come down at least 12 beats the first minute, and at least 30 beats within 2 minutes. Push it harder than this and you may not need a five year plan. Just sayin'. Greater reductions, and your heart is doing even better.
I have monster heart disease, dozens of blockages. CABG twelve years ago. A minor heart attack last October, and blockage they really wanted to stent, but they can't get at it, since the wires can not make a W in your arteries zigzagging in reverse up the artery tree.
ANYWAY, I used a concept I found here years ago to monitor my recovery, and workouts. If doing a long steady state workout, or even a strong but not all out interval, eventually your heart rate will start climbing. That climbing heart rate is a presursor to onset of fatigue. If you then back off the workout, or soon, and cooldown, you will actually avoid fatigue, and can workout again the following day. I rarely violated that rule in 10 years of recovery, and it let me regain great fitness for a guy who the cardiologist gave three years to live. I eventually went back on the water, and took up basketball and volleyball. One young man coolly commented that my rowing gave me plenty of strength and energy to outplay lots of younger guys on the volleyball court. For duration, and quickness, not skill.
I term that heart rate monitoring for cardiac drift. It was huge for me. Helped me take a tolerated heart rate of under 100 early in bypass surgery recovery, to easily working out with my heart rate over 170, and even to 183 for 30 minutes of basketball. That took a few years. I never had that as a goal. What I could handle just slowly improved, and kept on improving.
Most of your fitness will come back in a year. If careful with weight training, avoiding injury, you can double your strength almost every year, with just 5% weight increments every 3 weeks. THAT will let you take on almost anything. But you do need to keeo it up. Stop training, and your strength will slowly drop back at about 2-3% per week.
I also eat a very strict low fat diet. Not for weight control, but to stave off angina. It works.