Let’s call a spade a spade… Cardiovascular training can be a huge time suck. Both in terms of the actual amount of time spent and in the tediousness of it. And this is coming from someone who doesn’t mind spending some QT with a treadmill. That sense of dread is why HIIT is a thing. Who wouldn’t want all the benefit with less time input? While HIIT workouts are great, it is important to take a look at what you want from cardio training long term.
There are three training variables that govern workouts. Frequency, intensity, and volume. By knowing what these are and how to tweak them for both individual workouts and over time, you’ll be able to maximize cardio time. Frequency is, quite simply, how many days per week you are exercising. Intensity refers to how hard you are exercising, and in cardio world that means either your heart rate or rate of perceived exertion at a given speed. Volume can be measured in either distance or minutes of duration.
All three variables run on a continuum from low to high. For example, doing cardio training 2 days per week would be low, six on the high side. It is important to note that regardless of what your specific goal is, all three variables should not be at the high end of the spectrum at the same time. Or at least not for more than a couple workouts without giving your body a rest day to recover. Regardless of your specific goal, there are a few general guidelines to follow.
First, if you are looking to improve capacity (i.e. walk or run a mile without stopping), especially endurance, frequency is the name of the game. You’ll want to try and do something most days of the week. That’s the full seven day week, meaning at least four days of cardio. When you are trying to improve your heart and lung capacity, consistency is key. You don’t attempt it once and then forget about it for two weeks and hope to see improvement. Nope, you gotta keep after it. This is also important for maintaining long term heart health, which is why most of the exercise recommendations touted are cardiovascular in nature.
Second, if you are looking to advance training (i.e. run a faster mile, set a PR for time) you’ll want to bump up that intensity. Asking our heart and lungs to work harder than they are used to enables these systems to become more efficient. You can increase intensity either by pushing to go a little faster than last time, working with inclines (or resistance in the case of stationary bikes and ellipticals), or by adding intervals into your routine. This is where HIIT shines. Sure, it’s great for a quickie workout when you are short on time and the calorie burning benefits are awesome. But HIIT will also whip your heart and lungs into efficient machines like nothing else.
Third, whichever of the above groups you fall into, your volume (miles or minutes of exercise) should be enough to push you forward without causing injury. This is, truthfully, the tricky one. It’s also why runners are always hurt. Runners always want to go either faster or further. And it’s the drive to go further that has them adding miles when their body may not be able to handle it. You should pick distances or times that have you ending your session tired but feeling you could have been able to go a bit more. What’s a bit? 10%. So for a 30 minute session, could you have pushed three more minutes?
And because I love a good chart, here are some examples…
Frequency | Intensity | Volume | |
Improve Capacity | 5-6 days/week | 40-70% HRmax | ↑ from baseline 5% every week |
Run Faster | 2 days w/ HIIT
2 days steady pace |
60-85% HRmax | Holds relatively steady |
Run Further | 4-5 days/week | 60-70% HRmax | ↑ from baseline 10% every week |
Just remember, whatever your specific goal, frequency, intensity and volume are the players in this game. You shouldn’t have all three at the high end of the spectrum at the same time (results in injury), nor should all three be too low (results in lack of progress).