Am I Doing Cardio Exercise
at the Right Intensity? by Kurt Rawlins, CSCS
People often go about exercise haphazardly, assuming just doing it is enough to achieve results. Wrong! Exercise intelligently, and you will get results. Far too often, I see people having conversations on their cell phone or reading during their workout. Then there are those who insist on jogging for hours on end or churning their elliptical into the ground for 90 minutes. Trust me, if you can hop on an elliptical for 90 minutes, you can’t be working that hard! If you want
serious results, you have got to be serious about your exercise. Put the US Weekly away! A very smart person once said you can work hard, and you can work long, but you cannot do both. This is SO applicable when it comes to exercise, and the truth is, hard work beats prolonged work every time. In kinesiology, long-duration cardio is termed steady-state exercise. Typically, steady-state exercise is of a low intensity and is always below an individual’s VO2max, or the capacity of the body to get oxygen to working muscles for exercise. Once exercise surpasses your VO2max, the exercise becomes anaerobic. Anaerobic exercise is paramount to excess postexercise oxygen consumption, also known as “EPOC”. This phenomenon is the “oxygen uptake above resting values used to restore the body to the preexercise condition” (Baechle and Earle 35). Why is this important? EPOC is a critical factor in burning calories after you’re done exercising. That’s right, you can burn calories for
up to 24 to 48 hours after exercise, when you’re relaxing! That’s huge, and any exercise that’s anaerobic creates EPOC. How do you know if an exercise is anaerobic? Well, generally if you cannot maintain your current intensity after 90 seconds with an exercise, it is anaerobic. The oxidative system takes over after 90 seconds, and the exercise becomes aerobic.
Put simply, intervals are bouts of high-intensity exercise interspersed with lower intensity periods.
The best way to include an anaerobic portion to
base of steady-state cardio for six to eight weeks is ill
your cardio bouts is through interval training. Put
advised. Also, you shouldn’t need more than 25 or 30
simply, intervals are bouts of high-intensity exercise
minutes to complete an interval session; sometimes less
interspersed with lower intensity periods. Intervals
will suffice. Doing more than three days a week for 30
can be done with several ratios. You can literally come
minutes can lead to overreaching and overuse injuries.
up with hundreds of combinations of ratios during
When it comes to very short high-intensity training like
a session. As a general rule, the shorter and more
10 and 20-second sprints, use caution. These intervals
intense your high-intensity bout is, the longer your
are very intense and can lead to extreme fatigue the
low-intensity period should be, relatively speaking.
next day. Build up slowly.
For example, if you want to do 10-second sprints, your low-intensity periods should be at least a minute, or a
The treadmill and bike as well as outside running
1:6 ratio. If you want to run at a fast pace for 2 minutes,
are the best choices for interval training. Switch it up
then typically you can then slow down to a fast walk or
often to prevent overtraining and boredom. If you’re
jog for 2 minutes. This ratio, of course, is 1:1. The rest
feeling extra tired one week, listen to your body and
periods will allow your body to recover for the next
back off the intervals. A good rule of thumb is to do two
high-intensity bout.
interval sessions per week mixed with one steady-state session.
Intervals will mobilize fat stores more efficiently than steady-state exercise. This is because high-intensity
Next time you want to go for a run, remember this:
exercise will rapidly deplete your glycogen stores (the
steady-state, low-intensity exercise only burns
storage form of carbs in your liver and muscles). Once
calories during exercise. The advantages of doing
you deplete your glycogen levels, your body uses fat for
intervals are clear. Even though they may burn fewer
energy. A sample protocol would look like this:
calories during the actual exercise, in the end they will burn more calories through EPOC. The harder you work, the more EPOC you create. They take less time
2-3 days/week 20-25 minutes total 1 minute fast (RPE = 7-9) : 2 minutes slow (RPE = 3-5)
than steady-state sessions. They mobilize body fat by depleting glycogen stores. As if that wasn’t enough, intervals will increase your VO2max and therefore your overall fitness level. You get out what you put in, and the hard work is clearly worth it! Visit KurtRawlinFitness.com for more health &
RPE is the Rate of Perceived Exertion, using a 1-10 scale. Ten would be impossible, and one is way too easy. Intervals are intense, so doing them without at least a
fitness tips!