What is Sufficient Cardiovascular Exercise?
Of all the muscles we try to exercise in our various fitness routines and strategies, we often fail to properly address our heart -- the most important of all muscles! A recent study in 2018 found that the most important risk factor leading to heart disease -- more dangerous than diabetes, smoking, or high blood pressure -- is a lack of good cardiovascular exercise! (JAMA Network Open).
A good cardiovascular routine needs to be well planned in order to provide adequate exercise intensity and volume for the heart, as well as to create the optimal metabolic changes in order to burn body fat and achieve ideal long-term physical health. How is this done?
Well, one answer comes from research which reported significant increases in the HDL (good cholesterol) levels in men that exercised at or above 75% of their maximum heart rate (maxHR), 3 times a week for 12 weeks. No changes in HDL were reported in the subjects that exercised at only 65% of their maxHR. This specifically shows that only after a certain exercise intensity level is reached, the body starts to manufacture the correct carrier proteins to bring cholesterol from its body stores to the liver to be “burned” or used up! Without such level of stimulation, exercise is helpful in other ways, but one’s cardiovascular health is not as significantly impacted.
To calculate your training heart rate, take the quantity (220-Your Age) and multiply it by 0.75 to get your target minimum training heart rate which will positively affect your HDL levels. For example, if you are 40 years old, take (220-40) X .75 = (180) X .75 = 135 beats per minute for your cardio training heart rate.
Important Note:: If you are out of shape, start training at a lower heart rate level , say 65% of your maximum heart rate level, and then gradually build up to a 75% max heart rate level. A good rule of thumb is never exercise at a sustained level which has you breathing so hard that you cannot carry on a normal conversation. (I often recite a memorized poem to see if I can carry on a normal conversation.) When beginning exercise, also start with exercise duration of 5 or 10 or 20 minutes, and gradually add more time with succeeding sessions.
Exercise volume, however, has been found to be more important than exercise intensity. It was reported in studies that weekly total mileage was more important in raising HDL levels than was exercise intensity. Interestingly, a higher volume of exercise provided significant increases in HDL in a shorter period of time. This indicates that there may be a relationship between exercise volume and the length of the training program. Most of the exercise training studies identify a weekly mileage threshold of 7 to 10 miles/week for significant increases in HDL’s. This correlates with an average minimum work-out of 25 to 40 minutes, 3 times per week, at a gym on cardiovascular training equipment. If you are eventually able to exercise up to 60 minutes, it would be even better.