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Doing cardio can really suck. Especially, if you're doing it right
In order to trigger the physiological changes needed to increase your cardiovascular capacity you need to push your heart rate as close to your max as possible.
And things usually don't feel so good when your heart is beating is fast as possible. You're sucking wind, your throat, lungs and chest are burning, maybe your head feels like it's going to explode ...
So why do it?
If you're training for an athletic competition then it might be obvious. But what if you're not? Is it really worth pushing yourself to the limit once or twice a week?
Unfortunately (unless you enjoy sucking chest pain) the answer is yes.
Because intense cardio is usually less fun, it's helpful to have an understanding of what exactly it's doing to your body and why it's worth the discomfort.
At a high level, when you're training for cardiovascular and respiratory fitness you're making your body more efficient at oxygen delivery.
Efficient oxygen delivery matters for preventing cardiovascular disease and improving athletic performance.
It's important to note that training to improve oxygen delivery is actually a bit different than training to improve nutrient delivery which generally involves less intense exercise.
Because both systems are impacted by what's usually called cardio training they're often conflated.
But in order to drive adaptation in the system that manages oxygen delivery you're better off training in a way that really elevates your heart rate.
So what makes for efficient and healthy oxygen delivery?
The three main organs responsible for oxygen delivery include:
When your heart starts beating faster and your breath speeds up it's because your body needs more oxygen. To meet this need you have to pull in as much oxygen from the air as possible, infuse it with your blood, and then push it through your body.
The stress that comes from pushing your heart rate high enough will force adaptation across each organ.
In order to measure your cardiovascular and respiratory fitness there are a few metrics which approximate your body's ability to effectively deliver oxygen.
While age and gender do effect your resting heart rate here are some broad ranges for ages 36 - 55 in beats per minute.
Blood pressure is also affected by age and gender but in general lower is better. If you're under 50 you really shouldn't be higher than 120 / 80 while at rest.
Of course age and gender matters but here's some ranges. The measurement is in ml/kg/min.
In English that translates to how much oxygen per kilogram of bodyweight you can process in a minute.
Women (36 - 55 years)
Men (36 - 55 years)
Target levels between men and women are generally the same with the exception of HDL which should generally be about 10 points higher for women.
Everything is measured in mg/dL (milligrams per deciliter) and are based on a fasted blood test.
Healthy Cholesterol (mg/dL)
Unhealthy Cholesterol (mg/dL)
None of these are hard and fast numbers but general benchmarks to give you a starting point when thinking about your cardiovascular health.
Most importantly, it gives you a sense of what you should even be looking at and how to know if your current training regime is making an impact.
It all goes back to your goals but if overall health is one of them then knowing your numbers and integrating weekly exercise that pushes your heart rate close to the max will give the best results.
❤️
Nick