I'm fully aware there are a huge amount of people, namely women (no offense), who subscribe the theory that cardio and ab exercises will yield maximum results for their physique. They're under the impression, for whatever reason, 90 minutes of cardio and crunches every day will have them looking amazing. Let's just nip this one in the bud right now. They're completely wrong. If all you're doing at your gym is cardio and abs, I would highly suggest canceling your membership now because honestly, you're going to eventually wind up doing yourself more harm than good.
There are at least a few cliched quotes that come to mind when thinking about cardio. "Work smarter, not harder," is one of them. The other is, "less is more." Let me explain.
Work smarter, not harder.
The first thing you must do when determining how fast your heart should be beating during cardio is to figure out your maximum heart rate (MHR). There's a lot of ways to calculate this number, but the easiest one to determine a baseline is this:
- 220- your age = MHR Example: 220- 31= 189
Most people's goal with doing cardio is fat burn. Other people's goals are more conditioning related for sporting events. Whatever you goal is, there is an ideal heart rate you should be living in to achieve that goal.
- 55% MHR is the "fat burning zone." This is generally recognized as the best place to be if fat loss is your desired goal. So, using that calculation above, 55% of my MHR would be around 104 beats per minute. This is a fairly low heart rate, and for that reason, this type of cardio has almost zero effect on the heart and lungs. Additionally, in order to achieve any substantial benefit from this type of cardio, you have to do it for longer periods of time. 30 minutes to an hour is a good baseline, but too much of it can weaken your muscle and sometimes cause muscle loss. When you hear the term "steady state cardio," this is the type of cardio that is generally being talked about.
- When you hear the term "cardio," however, the actual definition of this means you're training somewhere in the 75-80% MHR range. Once again using the calculation above, that would put me at around 142-151 beat pers per minute. This type of cardio conditions the heart and lungs, and is a good way to better strengthen your VO2 capacity. That's just a fancy term for how well your heart and lungs use oxygen. The body's primary fuel for this type of cardio is the glycogen stores in your liver and muscles, which means you had better be properly fueled before doing it. As I explained yesterday, once the glycogen stores run out, your body starts looking to use free amino acids in your blood stream and if there are none, it will cannibalize your muscle. Yet another reason to make sure you include plenty of protein in your diet.
Reading what I just wrote, you may deduce that you should be doing either one or the other of those kinds of cardio. But wait, before you put your earbuds in and run off to do long form cardio at a lower heart rate, think about this. Your heart is probably the most important muscle you have. The obvious reason is that without it, you wouldn't be alive. The less obviously reasons are that a strongly conditioned heart makes nearly every other part of your body run better, from digestion to recovery from vigorous exercise. A strong heart also makes your body burn fat at an accelerated rate while at rest. This is the part where working smarter, not harder comes into play.
If you haven't read my Basal Metabolic Rate post, please do so now and determine yours. If you're eating correctly and getting the proper amount of calories for your goals, which I hope you are, you're almost completely eliminating the need for that 55% MHR cardio. In fact, if your calories are right and you're doing shorter durations of that 75-80% MHR cardio, not only are you strenghtening your heart and lungs, you're practically guaranteeing you'll be burning more fat than the person who is overly relaxed with their diet and does endless amounts of "fat burning" cardio.
I try to give all my clients the proper nutritional guidelines so at the most they only have to do cardio 2 to 3 times a week, and I rarely ever have them do long durations of it. It's boring, and unnecessary. Eat right. Lift weights like a beast. Condition your heart for optimal fat burning. Smarter. Not harder.
Less is more.
HIIT stands for High Intensity Interval Training. It's a method that's been around for a very long time, but is just in the last few years starting to catch on in a bigger way. HIIT is generally done for short periods of time, and involves bouts of all out effort at around 90% MHR followed by a designated period of slower pace or total rest, repeated for several intervals. In years past, it was used by track coaches who were trying to increase the performance of their sprinters. Back then, it was a known as the Fartlek method, which in Swedish means "speed play." Now it is being used in the fitness industry to literally destroy fat in training clients.
Some of the first studies on HIIT pitted interval cardio style training versus steady state cardio training. Despite the fact that over several weeks, the steady state people burned several thousand more calories than the people doing HIIT, the HIIT trainees lost significantly more fat. It seems implausible, but the reason it works so well is because HIIT increases your metabolic rate, even while at rest, for up to 24 hours after you finish. Other discoveries were that the HIIT trainees muscle fibers became extremely more efficient at burning fat as well as had a significant increase in enzymes that aided in the burning of fat. Definitely a win-win situation, even though these people were spending considerably less time on the cardio equipment.
Aside from the fat burning qualities that HIIT provides, it's also proved to be very adept at helping sparing muscle tissue, which is of benefit to people trying to pack on lean mass. By doing HIIT instead of long durations of steady cardio, many subjects actually gained muscle. Slow, steady cardio makes your muscle fibers used to low intensity nature of it, which means you are giving them a reason to be weaker (read: smaller). All out, explosive bursts of sprinting on the other hand tax the muscle into becoming stronger and often times bigger.
While I do prefer this method of cardio over any other, fair warning. The first couple session will leave you sore and exhausted if you do them right. That is because both your skeletal muscle as well as your heart muscle are most likely not used to giving total effort. Fortunately, the body is amazing at adaptation, and after a few weeks you'll be on (relatively) easy street.
So how is it done? Well, there's a huge number of methods, but I generally have my beginners do it one of two ways. Keep in mind, you can do HIIT on a track, sidewalk, treadmill or just about any other piece of cardio equipment as long as the desire result is achieved:
- Fartlek style: This is the old style of HIIT, but it's still very effective, and much less punishing on beginners until they condition themselves. 2-3 times a week for 30 minutes should be more than sufficient for most people following a steady diet and lifting weights. Fartlek is very simple. The interval is 5 minutes. For 4.5 minutes, you do nothing more than a steady pace, somewhere in the 55% zone we discussed earlier. For the last 30 seconds, you crank up the resistance on the cardio machine or take off at a dead sprint until you reach the 5 minute mark. At the 29 second mark, you're going to want to be somewhere in between "I can't breathe," and "I think I might die." Just then, 30 seconds is over and you're back to doing either a slow walk or a very low setting on the equipment you choose. Repeat this 6 times, and you're done. Simple.
- Updated HIIT: After you've become fairly adapted to the Fartlek style (2 weeks or so), it's time to graduate to HIIT as we know it today. There are a number of different ratios you can do HIIT at, but for beginners, I prefer the intervals to be somewhere in the neighborhood of 80 seconds. So that's 20 seconds of all out effort, followed by 60 seconds of very slow pace or even complete rest if you prefer. You can do as few as 3 intervals all the way up to 10, depending on your fitness level. I also recommend bookending these intervals with at least a few minutes of steady state cardio to warm up and cool down. As with Fartlek, you can do this 2-3 times a week. After you've become a pro at knocking out 10 intervals as described, it's time to graduate, but I'll discuss that in another post or you can contact me about setting up a custom plan!
- Calculate your Max Heart Rate (MHR) by subtracting your age from 220
- Doing cardio at 55% MHR for long periods of time is good for fat burning, but can weaken and shrink your muscles over time
- Doing cardio at 75-80% MHR is great for conditioning your heart and lungs, but too much of it can also cause you to lose muscle if not done properly with sufficient nutrition
- Doing HIIT style cardio is one of the ultimate tools for burning fat and preserving muscle in a much shorter time frame