It can be confusing knowing just how much to work out and how hard to work out. Fitness professionals toss in words like cardio and resistance and acronyms like BMI and BPM and it’s enough to scare newcomers away from any kind of physical activity at all. How do we begin to think about this?
Workouts are roughly divided into two kinds of activity. Cardio (short for Cardiovascular) means exercises that are designed to get the heart pumping and the blood circulating. Cardio exercises include running, elliptical, cycling (stationary or real!), swimming, and brisk walking. It is true that each of these will also work your muscles, but their primary effect is to circulate rich oxygenated blood to the rest of the body while exercising the heart muscle. Resistance (or weight) exercises are primarily designed to maintain or build muscles. Examples are most activities that are done on weight machines or with barbells/dumbbells, etc. These include bicep curls, lat pulldowns, and leg presses. Again, there is often a cardio component to these exercises but that is not their primary purpose.
Ideally, any exercise program should include a mix of cardio and resistance. Overall, we should aim for a combined total of 150 minutes of moderate to vigorous exercise each week. Additionally, those who have never really been active and are considering upping their game should check with their physician to discuss possible limitations based on medical history.
Assuming all that checks out, how can we tell if our cardio exercise is really doing its job? A lot of folks tell me that they walk (the dog, on the treadmill, around the block); this is a good thing, but is it really cardio? Is it raising the heart rate and exercising the heart?
There is a simple formula to determine this. It is not exact but gives a good estimate. Take your age and subtract it from 220. That number is your maximum heart rate. For example if you are 60 years old, your maximum heart rate during exercise should be 160 BPM (beats per minute). This can be calculated by taking one’s pulse or by any number of devices worn on the arm that can track this. Of course, training at the max is great if you are an elite athlete, but what about the rest of us? Ideally, we should aim for a heart rate (BPM or beats/minute) of 65-85% of our maximum. For a 60-year-old person this would be 65-85% of 160–or 104 to 136 BPM.
Don’t be shocked if you measure your heart rate during what you consider to be cardio and find it to be well below the number for the ideal range. First, if you are on a blood pressure medication, your numbers will be “artificially” kept low. Second, this is an indicator that you may not be working hard enough. If you are on a piece of gym equipment, it is easy to check miles/hour, strokes/minute, etc., and then work to increase that. Many machines also allow you to adjust incline or resistance; this is another surefire way to increase the heart rate. If you are walking the dog and your dog enjoys a sustained vigorous pace, you may find you hit the range; if, however, your dog (like mine) likes to stop and sniff every few yards, it is unlikely you will get into the cardio zone. Another activity on top of the dog walk may be necessary to hit that 150 minutes per week
The advantages of paying attention to heart rate are many. It prevents us from working too hard and causing harm through overtraining, and also prevents us from not working hard enough and not getting the full benefit. When we do cardio on a regular basis, we help to strengthen our hearts (the most important muscle in the body), increase blood flow to the cells, and to the brain. Cardio exercise is the only clinically proven way to prevent or delay the onset of dementia since it assists in the proper “feeding” of the brain with oxygenated blood.
As for resistance training, how do we know if we are working too hard or too little? Watch for an upcoming blog post on that topic.
In the meantime, check your numbers. You may be pleasantly surprised…or find that the hard work is still ahead.