How to improve your Cardiovascular Endurance
How to Improve Your Cardiovascular Endurance
Yuri Elkaim, BPHE, CK, RHN
Aerobic (or endurance) training improves cardiovascular endurance by increasing both maximal cardiac output and your muscles ability to extract oxygen from the blood. Thus, a training program designed to improve your cardio endurance must overload your circulatory sytem and challenge the oxidative capacity of your working muscles.
As with all training programs, specificity is crucial. If you are a runner and want to improve your aerobic endurance, then you need to run - not bike or swim. Likewise, if you are a cyclist who wants to become more proficient at biking up hills, then that's where you need to spend more of your training time.
There are 3 principle aerobic training methods used to improve endurance. They are interval training, long duration/low-intensity, and high-intensity, continuous exercise. Although, there are plenty of studies that validate the use of each method of training, the majority of the research shows that it is INTENSITY, not duration, that is the most important factor in improving your cardiovascular capacity.
For that reason, I personally use and prescribe interval training and high-intensity continuous exercise. Not only are they highly effective but they are also very time efficient. Let's look at each one in more detail.
Interval Training (or HIIT)
Interval training (or high-intensity interval training or HIIT) involves performing repeated bouts of high and low intensity exercise. The length and duration of the high intensity work bout will depend on what you are trying to accomplish (ie. your goals).
For instance, a longer work interval requires greater involvement of aerobic energy production. This is occurs becaue longer intervals need to slighly lower in intensity (or speed) than shorter ones. After all, for how long do you think you can possibly sprint? Not much longer than maybe 30 seconds.
On the other hand, shorter, more intense intervals, such as sprinting, involve a greater amount of anaerobic energy production. This is the energy system that gives you a lot of ATP (or energy) in a short amount of time but it is also an energy pathway that fatigues quickly and produces lactic acid in your muscles. That's why higher intensities can only be sustained for a short amount of time.
In planning your interval training workouts, you need to consider several factors:
length of the work and recovery intervals (duration)
intensity of the efforts (intensity)
number of sets
In general, in training to improve cardiovascular endurance, the work intervals should last longer than 60 seconds in order to get maximum involvement of the aerobic energy system. You can monitor your intensity by taking a 10-second heart rate by checking your pulse. Ideally, your work interval should elicit an intensity that represents 85% to 100% of your maximum heart rate.
The recovery interval could consist of brisk walking or light jogging to bring down your heart rate, ideally to about 120 beats/minute by the end of the recovery bout. Note: as you get fitter, your heart rate will drop much more rapidly, allowing you to recover more efficiently.
Depending on your fitness level you will want to choose a work to recover ratio that is suitable for you. For instance, as you get fitter aerobically, you won't need as much recovery time as you would when you first started. So, if you just starting to run intervals you may want to begin with a work to recovery ratio of 1:3, meaning that your recovery bout will be 3x as long as your work interval. If you ran 1 minute for your work bout, you would recover for 3 minutes, for example.
As you improve your cardiovascular fitness, that ratio would go from 1:3 to 1:2 and then down to 1:1, and even lower. Ultimately, the goal of interval training is to get your body used to running (or exercising) at a faster speed for a longer period of time. And that will get you ready for the next training method.
High-Intensity, Continuous Running
If two people are running, the one who can run faster for longer will win. It's as simple as that. This form of training (along with HIIT) will help you become a much faster runner.
How? Because it conditions your body to maintain a fast pace for as long as possible. Thus, numerous physiological changes occur that will improve your running endurance. It is believed that running a intensity between 80-90% of your maximum heart rate is optimal. Furthermore, it seems likely that a work rate that is equal to or slightly above your lactate threshold provides excellent improvement in your maximum aerobic endurance.