I have a simple question, from a cardiac perspective, how much exercise is enough? I have heard everything froom 30 minutes at least three days per wek, to most days of the week to every day of the week. Does the amount depend on the individual? In my case, I am a 49 year old male with controlled blood pressure and cholesterol numbers, no family history and have never smoked. I am still 50 pounds over weight but have lost 50 pounds in 1 1/2 years. I am limited in what I can do due to the OA in my knees and RA everywhere else, but besides the knee pain I have no\problems or other symptoms while exercising, I just need to keep it under a run and stay a a fast walking rate. Right now, I'm doing 45 mins per day on a treadmill or until I burn 500 calories and get in 3 miles at a minimum, even on days I travel, I always find the exercise room. Some days it takes longer than others depending on my knees. I am able to maintain 80 -90 % of my maximum heart rate for about 40 mins before i start my cool down. I watch my blood pressure and heart rate and have appropriate responses on both plus I recover quickly. Is this overkill, am I keeping my heart rate too high? I feel like I'm failing when I have a day I can't exercise due to an illness or if my knees are not up to it. What is the ideal amount of exercise to keep one's heart healthy?
Thanks in advance for your thoughts.