February is heart month. With hearts at the centre of your attention, let’s discuss how you can keep your heart healthy. Cardio, CV or cardiovascular workouts, are all common expressions referring to a specific type of exercise that challenges the cardiorespiratory system. But what is it exactly and how much and for how long should you be doing it?
There are many philosophies on the best way to train and many questions that remain. Let’s turn to the science of training the cardiovascular system for a better understanding. Here’s what we know: physical activity that includes cardiovascular activity is by far one of the most potent “drugs” there is, and the side effects are positive. The prevention of heart disease is rooted in a lifestyle of exercise, healthy eating and stress management.
The heart beats about 2.5 billion times over the average lifetime, pushing millions of gallons of blood to every part of the body. This steady flow carries with it oxygen, fuel, hormones, other compounds, and a host of essential cells. It also whisks away the waste products of metabolism. When you push your body to produce more energy than it is used to producing, the body will immediately accommodate for the increased effort by amplifying your heart rate. In this way, it provides more blood flow, oxygen and nutrients to the working muscles.
When the cardiovascular system is untrained, the amount of work the body can handle at any heart rate is less. When the cardiovascular system is functioning optimally the level of intensity of work goes up with less effort needed to perform the work. In other words, you can work harder with less effort at a lower heart rate. Therefore, all activity, whether it is mild or intense, is easier to perform. Think of it like learning a new sport. When you start something new you waste a lot of energy mastering the skill. Once you are skilled you are far more efficient and it requires less effort on your part. The cardiovascular system is similar in that it will adapt to the demands placed on it.
In the late ’70s, “aerobics” became a household word and people everywhere began understanding the idea of aerobic training for improved fitness and health. This form of training is based on staying within a manageable level of exercise intensity at approximately 60-85per cent of your maximum heart rate for periods of 15 minutes or longer.
Our bodies have three basic energy systems with three distinct purposes to provide fuel for activity. The aerobic system is the one you use daily for low level function as well as low to moderate intensity exercise for long periods of time. This is referred to as your endurance intensity. The aerobic system uses oxygen to break down the fuels, carbohydrates and fats, we ingest for function. This complex breakdown of energy is performed at a lower intensity of work to allow time for the chemical processed to take place. The aerobic system continually restocks the muscles cells until the intensity and duration of work is too high. At which point the body needs rest to restore.
By contrast, the anaerobic system is reserved for higher levels of physical effort of over 85per cent of maximum heart rate. The anaerobic system has two subsystems based on the type of fuel used, the intensity and duration of the activity. The quickest and most powerful system for short intensive efforts is in simple terms your speed and strength system. It is used in sprinting and weightlifting and has a short lifespan of about 3-15 seconds. The energy is stored in the muscle cells and once used need to be replenished with recovery.
The second anaerobic system is called the glycolytic system as it uses glucose or carbohydrates for energy. The lifespan of this energy system is longer, lasting anywhere from 30 to 120 seconds and works in concert with the aerobic system. This is the system that most HIIT programming challenge and can consist of a mix of resistance training and intensive short cardio intervals.
All three energy systems should be trained based on our current fitness level, health considerations and goals. Effectively planning your fitness program will give you the best results to insure you are neither under-training or over-training. The key to effective HIIT training is not only a well-designed set of work intervals but appropriate recovery during and after the workout.
Monitoring cardiovascular intensity can be done with a heart rate monitor or simply using a perceived level of exertion by rating your effort on a scale from 1 to 10. One being no work and 1o representing your maximal effort.
Keep in mind that exercise stresses the heart, in a positive way, to improve overall cardiovascular effectiveness and resilience. However, it is important to balance your workouts and life stress with heart calming activities such as meditation, restoring yoga and stretching. Also, refuel the body appropriately to the exercise intensity and volume of work. Diet and rest play a critical role in recovery, results and overall heart health.
There is no one precise qualified amount of training that is best for everyone as each of you has your own unique physiology, health concerns, goals and lifestyle. Unless you are training for a specific sport or event, the best recommendation is to balance your weekly, monthly and yearly cardiovascular fitness program with a wide variety of training style that focus on both aerobic and anaerobic activities. Cardiovascular training should be performed a minimum of four times per week for 15-20 minutes of steady state unless HIIT training, which can be done in a shorter period of time. Be conscious of other stressful events in your life as heart rate and blood pressure are negatively affected by stress. During stressful periods choose activities that are less stressful to the heart as it is already working hard due to other factors.
Be smart about your cardiovascular training and be kind to your heart.