Cardiovascular fitness can simply be defined as the ability of the body’s respiratory, circulatory and muscular system to extract, consume and distribute oxygen from blood during a continuous level of physical activity. When you breath in air your body does not consume 100% of the oxygen inhaled and most of the oxygen is exhaled back into the air you breath out. The amount of oxygen you consume will depend on your level of cardiovascular fitness. Having a poor level of cardiovascular fitness is as strong a predictor for heart and cardiovascular disease (the #1 killer in the United States) as other health issues such as smoking, obesity, hypertension and diabetes.
Research has proven that even small improvements in cardiovascular fitness can significantly reduce your mortality and risks of heart and cardiovascular disease, so there is no need to become a pro athlete or marathon runner to reap the full benefits of cardiovascular health.
Measuring Cardiovascular Fitness and Mortality Risks
There are several mechanisms in place that can explain how cardiovascular fitness can decrease mortality. One key measure that comes to the forefront is by measuring insulin resistance. Insulin resistance is a condition in which the cells of the body become resistant to the effects of insulin, impairing their ability to take up and use glucose for energy. Improved levels of cardiovascular fitness are directly correlated to improved levels of insulin sensitivity, which can help prevent or better manage type 2 diabetes.
Another mechanism is by measuring all variables that determine if a person has Metabolic Syndrome. This includes waist circumference, triglyceride levels, HDL cholesterol, blood pressure and fasting blood glucose. People with higher levels of cardiovascular fitness have a lower risk of all metabolic syndrome variables and people with metabolic syndrome have increased chances of developing cardiovascular disease and diabetes.
Stronger Faster and Better Body
When a person has higher levels of cardiovascular fitness they experience a much lower level of perceived effort than someone who’s cardiovascular fitness levels are low. This means you are able to exercises longer, harder, burn more calories and achieve your goals faster with less fatigue and shorter recovery time than someone at a lower fitness level exercising at the same intensity. This is because you have a stronger heart, larger lungs and all components of the cardiovascular system don’t have to work as hard to deliver oxygen and fuel to working muscles.
There are several physical and hormonal factors taking place in the body causing the improvement of cardiovascular fitness, but only a few of these factors will be covered in this article. A stronger heart is one of the more well-known factors, but it is by far not the only improvement. The heart is a muscle just like any other and when you force it to work harder, it goes through improvements in order to better handle the additional work load. These improvements include getting bigger and stronger and increasing its stroke volume and capacity. This is why measuring your resting heart rate can determine your cardiovascular fitness. Your lungs also get larger and the microscopic capillaries in your lungs which are responsible for extracting oxygen from air increase in density. It’s like having a better air filter with denser fibers for your lungs.
The capillaries surrounding and inside all muscles of your body. Capillaries look similar to branches on a tree where more branches grow and increase in density. The increased density of capillaries in a larger heart, muscles and lungs allow for one key thing. For you to extract more oxygen from air so that you can burn more fat, retain more glycogen, experience less effort and reach goals faster. You’ll become a more efficient energy burning machine during exercise and also rest. You’ll experience a better quality of life 24 hours a day, burning more calories even at rest. This is just a small fraction of cardiovascular fitness benefits because the physical and chemical changes are too numerous to be covered in one article.
Cardiovascular fitness is an excellent measure for all bodily functions associated with cardiovascular disease, as well as all causes of mortality. Here is a list of bodily functions that cardiovascular fitness can have a positive impact on.
- Improved insulin sensitivity
- Reduced chance of metabolic syndrome
- Decreased body fat
- Lowered LDL (bad) cholesterol
- Elevated HDL (good) cholesterol
- Decreased abdominal obesity
- Decreased Blood Pressure
- Decreased apolipoprotein B
The best way to improve cardiovascular fitness
For greater improvements in cardiovascular fitness, the American College of Sports and Medicine (ACSM) advocate 3 – 5 days per week of cardio exercise at 64% - 94% of maximum heart rate for between 20 to 60 minutes per session. For interval style training you should progressively increase intensity and duration to see steady and continuous improvements in cardiovascular fitness.
