Recommendations for Cardiovascular Training
The American College of Sports Medicine recommends you train your cardiovascular system every other day for 30 to 40 minutes. The American Heart Association recommends 30 minutes daily. The Centers for Disease Control and Prevention suggests at least 30 minutes of moderate physical activity most days. Studies have shown that even spending 10 minutes at three separate times a day can make a difference. So if you can't find 30 minutes in one block of time, then try several bouts of 10 minutes.
The fact of the matter is that anything is better than nothing. People have achieved nice results spending 20 minutes three times a week. You ask, "Can I do more?" Absolutely! By doing more you will be able to burn more calories and possibly see greater improvement in the efficiency of your heart and lungs. However, remember, more isn't always better. Listen to your body. If you feel worn out all the time or find yourself not looking forward to exercise, that may be a sign you are overtraining. If this is the case, cut back and allow your body to recover.
I've worked with many people in the past who feel that if they aren't seeing progress, they need to do more. This will often lead to burnout or injury, therefore really halting progress. Take my word for it, more is not always better and it doesn't hurt to take a couple days off here and there.
