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As most of you know, I’ve been following Bill Phillips’ Body for Life program for the past nine days. I like it. I can already tell a difference, not just in my physical well-being but in my mental well-being. I love to be able to feel the muscles in my thighs (instead of just the fat).
Body for Life takes a three-pronged approach:
- Many small meals of protein and carbohydrates.
- Strength training through “weight intervals” (my term, not his).
- Aerobic exercise using “intensity intervals” (his term, not mine).
I’m nailing the first two portions of this program just fine. They take effort, but I’m doing them. The final step, though, is more problematic.
Under Body for Life, you do aerobic exercise three times each week for twenty minutes per session. Each minute is carefully prescribed. During the first minute, you work out at 50% intensity, and the same in the second minute. Then you work out at 60% in the third minute, 70% in the fourth, 80% in the fifth, etc. The full breakdown of the twenty minutes looks like this (using a scale of 1-10):
I have a few problems with this. First, I’m not used to working out at peak intensity, not even for one minute. Second, I don’t know how to define peak intensity, let alone 90% intensity or 80% intensity. Is this entirely subjective? Or am I supposed to use some objective measure such as heart rate?
Finally, I’m accustomed to doing long, moderately strenuous aerobic workouts. A few readers scolded me for doing 60-minute recumbent bike sessions, but they’re really not a problem. Even at 80% heart rate, I can go for quite a while. (My body is built for biking.)
I guess my question is: What is the rationale behind the Body for Life intensity intervals? Is there a reason to pursue these other than “that’s what the program says to do”? (Which may be a valid enough reason, I grant.) On Thursday, I hope to swim for the first time in ten years. But I have no idea how to do intensity intervals with a swimming session. I was just going to hop into the pool and go for thirty minutes.
I have another question, too.
On Saturday I bought a heart-rate monitor. Not very frugal, I know, but I’m trying to be serious about this fitness thing. I figure that in the long-term, the expense will be repaid by better health.
Anyhow, I fed some parameters to the monitor and it told me my Maximum Heart Rate was 182bpm. I know that it’s just using the (220 - age) formula. But today at the gym I tried a Body for Life “intensity interval” on the elliptical machine. My pulse reached 194bpm, so obviously 182 is not my Maximum Heart Rate.
What does this mean? Should I be worried? Does it matter that my Maximum Heart Rate is higher than the theoretical? Is it better to have a lower Maximum Heart Rate? Or is this just something where I should adjust my monitor to the new observed Maximum, and then adjust my workouts to match? (As a point of trivia, the highest pulse rate I’ve ever measured on myself was 224. This was when I was 18, the summer after I graduated from high school. I had just hiked briskly up a steep slope. I was very very nauseated.)
Anyhow — I know these questions are probably dull for most of you, but they’re the sorts of things I think about while exercising!
Mac
24 responses so far ↓
1 Dave // Mar 18, 2008 at 8:00 am
As far I know, Maximum Heart rates are kinda like the red line on a tachometer. You can easily go above it, but its generally a bad idea. And don’t forget - as you exercise the amount of effort to get up -to- that level will increase as your body gets more “efficient”.
I will say that this is all off my my experience in losing about 70 pounds thru running.
2 Amber // Mar 18, 2008 at 8:14 am
I just read a book called “Ultimate Fitness: The Quest for Truth about Exercise and Fitness,” and there was a whole chapter about heart rate. The maximum heart rate formula is (of course) just an average, and apparently not even a very good one. People’s max. heart rate can vary a huge amount from that number, and there were some elite athletes in the book whose max. heart rates were much higher than what the formula says. I don’t think it’s a good or bad thing. It just is.
Also! I would say not to get obsessed with whether you’re working out at an intensity level of “5″ or “6″. Instead, look at the trend of the intensity he’s set up: you increase your intensity until you’re almost at your max for the first 6 minutes, back off for a minute and then increase again, back off and then increase again, then do it again but work even harder for an extra minute, and then cut the intensity dramatically.
I know you can see the trend, but my point is that sometimes we (myself included) can’t see the forest for the trees, and this is definitely a time when you need to look at the forest. I hope that made sense.
3 Mark // Mar 18, 2008 at 8:28 am
First off, congratulations on seeing and feeling the progress you are making! That is the most important part of the whole process. I have a couple of observations (based totally on my own experiences) that might be helpful.
First, regarding the “intensity intervals”. I think (at least I hope) that what they mean when they say intensity is “perceived effort”, not heart rate. It is virtually impossible to use heart rate as a determinant of intensity, especially on such short intervals, as heart rate tends to lag effort. I would consider a “5″ as a pace you could keep while holding a conversation, while a “10″ is all out holding nothing back and gasping for air. A 7 or 8 would be fairly hard to do anything more than a couple of words at a time and your breathing is a bit labored. Also, I personally think that aerobic exercise should be longer than 20 minutes, more like 30+. I would warmup for 10 minutes, do the 20 minute interval, then cool down for a few minutes. Doing short efforts at higher intensity has been proven to increase fitness so they aren’t bad. I know when I ride and I want to do harder intervals I will do 5 sets of 3-5 minutes at a level of 7-8 followed by recovery of 2-4 minutes along with a good worm up and cool down, maybe 75-90 minutes total.
Regarding heart rate. Everybody has a different “max” and a high max doesn’t mean you are more, or less, fit. It’s just a number. As you found out the 220-age way of figuring it isn’t accurate. I would say use the perceived effort method and correlate that to your heart rate over a few workouts to get a good idea. My guess is you will find that your heart rate at “6″ on the scale will be somewhere around 140-150. Once you have a baseline on your heart rate you can use your monitor more effectively.
Hope that helps. Have fun!
4 Aaron // Mar 18, 2008 at 8:30 am
I define max heart rate as “The heart rate I hit when I feel like I’m going to throw up.” Maybe not the most scientific definition, but that’s my yardstick. Sort of the aerobic equivalent of pushing yourself to muscle exhaustion/failure while lifting.
As you get more fit, that will adjust so you need to recalibrate every once in a while.
5 A // Mar 18, 2008 at 8:51 am
“What is the rationale behind the Body for Life intensity intervals?”
The idea of this kind of training is essentially to ramp up your metabolic rate in general rather than simply burning calories while on the bike. Repairing tissue damage such as occurs with heavy weightlifting or intense cycles such as this requires a high degree of metabolic activity, and some people think that regularly training in this manner can elevate your basal metabolic rate. In other words, it’s not just the calories your burn while on the bike but the calories you brun FIXING what you did on the bike.
I’m not sure how well this is supported by phsysiological research, but the basic principle seems sound since it simply takes a lot of energy to repair your body regularly, and our energy ultimately comes from either fat our food.
6 Another Amber // Mar 18, 2008 at 9:00 am
I just started an interval training program, too, with a web interface that tells me exactly what I should be doing during each minute of my workouts. I use a heart rate monitor.
The first step when signing onto the web site was to calculate my anaerobic threshold. In my research on this I’ve learned that the anaerobic threshold is the point past which your body builds lactic acid, which accelerates muscle fatigue. It is calculated at about 85-90% of the max heart rate. Because I am overweight and had been only moderately exercising before starting the program, the web site calculated my initial AT to be 168.
My program uses a series of intervals and recovery periods, so it is a bit different from yours. The recovery periods allow oxygen in the body to dissipate any built up lactic acid. A typical 45 minute workout for me looks like this:
5 minutes warm up to 30 below AT
4 minutes at 15 below AT
2 minutes recovery (30 below AT)
4 minutes at 10 below AT
2 minutes recovery
4 minutes at 5 below AT
2 minutes recovery
4 minutes at AT
2 minutes recovery
4 minutes at AT
2 minutes recovery
4 minutes at 5 above AT
5 minutes recovery and cool down
After each workout the web site asks me how tired I was at the end of the intervals, and how many more intervals at the highest level I think I could have done. It then adjusts my AT upward if I think I could have done more. The goal is to increase my cardiovascular efficiency, which would move my AT up closer to the 85-90% of max heart rate (220-age) goal. At this point I am not working anywhere close to my max heart rate. Not only is my body not ready for that, but I’m sure my mind isn’t, either, and I’d burn out and start dreading my workouts.
Like I said, I had been exercising before, so when I tried out the monitor for the first time with my AT information programmed in I was curious what it would feel like to work in that target zone. I was surprised to find out that I had to push myself pretty hard to get to the AT and 5 above AT levels, but that the speed needed for recovery was much slower than I thought to be useful. The best part about this program is that I finally feel like I approach each workout with confidence. I’ve only been doing this for a week but I have already pushed my AT up and I find myself having to work even harder to get to the upper interval levels. I’m also running for the first time in my life, so big changes are afoot.
Good luck with your plan!
7 Eric Nagel // Mar 18, 2008 at 9:32 am
My take on this…
Your maximum heart rate can be approximated by a simple formula (age from 220), but in reality it goes up as you train. I just finished a long run (after not running for 3 months) and as soon as I plugged in my GPS to my computer, it notified me that my maximum heart rate had been updated. So it will change.
As for the % of intensity, I go by a subjective perceived level of effort. Obviously, I know what 0% is, and I know what 100% is. Then, fill in the gaps.
I do a sprints training session where I run 0:30 at 80% (fast run), 0:20 at 90% (end of a race run), 0:10 at 100% (chased by a lion run), then back down (0:20 at 90%, 0:30 at 80%) with 2:00 in-between each one at 40% (slow jog). While the entire workout, including warm-up and cool-down, takes less than 20 minutes, over a few months I can run my 5k’s much faster.
I hope you got something useful from this - keep up the hard work!
8 Andrew is getting fit // Mar 18, 2008 at 9:49 am
I think you’ll find the money spent on the Heart Rate monitor is money well spent. I use mine and it really helps to keep the intensity of the workouts up.
9 Allen // Mar 18, 2008 at 9:54 am
I’ll echo similar sentiments on here when I’d say that the intensity level is subjective. I take a regular spin class and our instructor always suggests a 1-10 scale, with “5″ being a flat road, “6″ a small hill, etc.
The interval training concept, like A said above, is not only the burn of calories/fat during the workout, but the burning of the calories after the fact. There’s several programs that suggest this is the best way to lose fat. You’re essentially shocking the body during the peak exercise portion and allowing for a recovery period. The interval training also shortens your overall workout, as you should be burning more calories/fat than a typical 60 min session. Only do that for endurance training. To lose fat, stick with the intervals.
Also, I’d return the heartrate monitor and invest in things to measure your bodyfat, like calipers or even a bodyfat scale. Don’t worry about what your heartrate is. You’ll end up focusing on the wrong things. What’s your goal?? If it’s to improve your heartrate, just about any cardio is good, regardless of the rate your heart beats. Fat loss is even better for your heart.
Keep the good work!!
10 Amy // Mar 18, 2008 at 9:57 am
Like others said, your max heart rate is more of an average for people your age. If yours is 8 or 10 beats higher, I don’t think that’s all that significant. It might be helpful to think about your “rate of perceived exertion” (here’s a brief explanation: http://www.sportfit.com/sportfitglossary/RPE.html) along with the heart rate monitor to figure out what 100% really means.
11 Matt // Mar 18, 2008 at 10:44 am
I’ve done Body For Life in the past with excellent results. Congratulations on getting off to a good start. The key to the program is that the three components - the eating plan, the strength training plan, and the interval training - all fit together. Each relies on the other two. The ultimate goal is to crank up your metabolism so that your body becomes a fat burning machine. It does this in the short term via the eating plan and the nature of the workouts, but it does it in the long term by adding lean muscle mass.
The interval training approach that Phillips espouses is good for three reasons:
1) It’s time efficient and never boring
2) It boosts your metabolism significantly for up to 24 hours after the workout is over
3) It doesn’t lead you to break down muscle, so you can recover from the previous day’s strength training workout
Long distance/low intensity training can also be worthwhile. But it works at cross purposes to the BFL goal of putting on muscle. You’ll end up breaking down your muscles when you lift, only to break them down again while doing an hour of slow cardio. You won’t put on much muscle in such a scenario, which defeats a lot of the purpose of Body For Life.
Picture a sprinter and a marathon runner in your head. If you’ve watched any Olympic track and field, you’ll notice that their bodies have fundamentally different shapes. Body For Life, in essence, is about building the sprinter’s body. Lower intensity cardio is about building the marathon runner’s build. Neither of these is “wrong,” they’re just different. But you really can’t build both at the same time.
–
Matt
P.S. Here’s a wikipedia article on high-intensity interval training, which is what you do on the Body For Life program. It has links to some of the research, which I hope you’ll find helpful.
http://en.wikipedia.org/wiki/High-intensity_interval_training
12 Roger Mudd // Mar 18, 2008 at 11:06 am
The exertion level postulated by BFL is a bit nebulous. I’ve had great success with this program, however.
My solution was to simply use the MPH settings of the treadmill as benchmarks. If I recall correctly, I started the first two minutes at a brisk walk (4 MPH) and then jumped to 5 MPH for the third minute, working my way up either 1/3 or 1/2 MPH for the following four minutes. Here’s how the MPH progression would look over the course of a 20-minute workout:
4–4–5– 5.5–6–6.5– 5–5.5–6–6.5–5– 5.5–6– 6.5–5–5.5–6–6.5– 7– 4
Doesn’t look like much, but it’s tough when you’re first starting off. Sometimes I couldn’t keep the pace and had to slow the treadmill down. No worries. Just kept on trucking and finished the workout sticking as close to the plans as I could.
It adds a whole new level of difficulty to the exercise.
If I was able to complete the regimen, I would start the third minute 0.5 MPH faster the next time. So in this instance, minute three would be 4.5 MPH and minute 19 would be 7.5 MPH — bumping each pace in between 0.5 MPH as well. Soon I was maxing out the machine at 10 MPH in the 19th minute. (BTW — I always started and finished at 4 MPH, using this pace as a warm-up and cool-down).
At that point, I started to introduce incline into the equation. That’s when you know you’re getting somewhere
I like the treadmill because it isn’t forgiving. You can’t “fool” it. Just be careful when you’re using it a high speeds.
13 J.D. // Mar 18, 2008 at 12:14 pm
I will surrender my need to analyze everything, and simply have faith in the Body for Life interval thing for a couple of weeks. That’s a total of six sessions (one of which I’ve already done, and which felt great) of 20 minutes each.
If I don’t think it’s working after that, I’ll try my way, but you’ve convinced me that I’m being a fool to try to do my own thing without even giving BFL intervals a try.
14 J.D. // Mar 18, 2008 at 12:20 pm
15 D // Mar 18, 2008 at 1:29 pm
JD - I know you’ve responded in the comments, but be careful of justifying going off the plan laid out for you because of “what worked in the past” or what you feel your “body was made for.” You’re not a fitness expert as the author (supposedly) is, so perhaps you should follow their advice for a bit before you go off on your own? It’s exactly like you preach on GRS, the books are a good place to start, to gain ground and a foundation, then as you feel more comfortable you can tailor things to your own needs.
-d
16 greenman2001 // Mar 18, 2008 at 2:18 pm
I wouldn’t be surprised if this generated as many comments as your bread post. People love talking about their heart rate and their heart rate monitors.
I notice that the personal trainers haven’t weighed in here either. I wonder if it’s because they see hordes of new gym members with heart rate monitors swarm the elliptical machines on Jan 2 each year, and disappear by March 2, rendering the heart rate monitors somewhat irrelevant.
I’m intrigued by Matt’s post, in which he says that an hour of slow cardio breaks down your muscles. I’d like to learn more about this, since my understanding is that cardio doesn’t break down muscle unless you’re doing interval/sprinting to build muscle. I know you will burn somewhat more fat doing interval training, but I thought this all fell far short of the effort needed to actually break down muscle in the way weight training does. Weight lifters will tell you that cardio is strictly for looks: they can burn all the fat and calories they want just by building muscle and letting it burn calories.
A’s comment is fascinating, and I’d love to see the research that supports this idea. Is this the argument that Bill Phillips makes?
17 Cynthia // Mar 18, 2008 at 3:33 pm
As has been said, the formula for max heart rate just doesn’t work for everyone. I also notice that I can push above what my 90% rate “should be” without a problem.
As for intervals, if you can not do an entire minute at peak performance, simply do less and work up. No different than working from one push-up to many.
Interval training, steady-state cardio and weight training can all have a place in your exercise program.
I really like my heart rate monitor… it’s a good way to be sure I’m not slacking!
18 Cynthia // Mar 18, 2008 at 3:33 pm
As has been said, the formula for max heart rate just doesn’t work for everyone. I also notice that I can push above what my 90% rate “should be” without a problem.
As for intervals, if you can not do an entire minute at peak performance, simply do less and work up. No different than working from one push-up to many.
Interval training, steady-state cardio and weight training can all have a place in your exercise program.
I really like my heart rate monitor… it’s a good way to be sure I’m not slacking!
19 Sarah // Mar 18, 2008 at 4:13 pm
I won’t say much, for all of the advice that has been given here in the comments already. I will say these things, though:
- That particular formula for max HR is really weak (as already noted). I’m at work, and don’t have time for a lot of Internet research, but look for a formula that involves your resting HR (measured first thing in the morning, before you even sit up in your bed, averaged over 5 days).
- I like using perceived exertion as a measure of intensity - at 50%, I am working, but I can carry on a conversation just fine. 60-70%, I have to breathe heavy in between sentences. 80-90%, gasping between words. 100%, I want to kill whoever is trying to talk to me.
- I love my heart rate monitor, but its biggest use to me was in the first few weeks of use. I learned to associate my RPE with a particular heart rate range, so I knew instinctively after that how hard I should be working.
20 Brigid // Mar 19, 2008 at 5:35 am
No matter what you end up doing (long/low intensity, short/high intensity) - it’s a damn sight better than what you were doing a year ago:-) Keep up the great work!
21 Megan // Mar 19, 2008 at 8:42 am
I don’t think anyone has commented yet on swimming to an interval. Instead of swimming for a straight 30 minutes while trying to keep track of when each minute has passed to change the intensity, I would recommend swimming a multiple of lengths that brings you closest to a minute for each intensity level.
For example, if it takes you 1 minute 30 seconds to swim two lengths at an intensity of 5, then try to swim two lengths in 1:25 for an intensity of 6, then two lengths in 1:20 for an intensity of 7 and so on, dropping 5 seconds with each intensity step.
If it took you 1:30 to swim one length, then you swim one length trying to cut off some time for each intensity level, it doesn’t have to be a 5 second step, just whatever feels like an appropriate change in effort. Or if it took you 1:00 to swim one length at an intensity of 5, use that as your starting point and decrease times from there.
This may end up taking slightly more or less than the original 30 minutes, but I’ve always found it easier to break up swimming into lengths instead of times.
Hope this helps and isn’t too confusing!
22 Josh // Mar 19, 2008 at 8:54 am
greenman2001:
“I’m intrigued by Matt’s post, in which he says that an hour of slow cardio breaks down your muscles. I’d like to learn more about this, since my understanding is that cardio doesn’t break down muscle unless you’re doing interval/sprinting to build muscle.”
Greenman make sure you’re not confusing muscle atrophy with hypertrophy. Long bouts of cardio can cause atrophy which is the loss of muscle cell size. Intense intervals (poor man’s weight training?) cause microscopic muscle tears (in myosin/actin) which, with proper nutrition/rest, can result in larger muscles — this is hypertrophy. One shouldn’t expect much muscle growth from HIIT in my opinion, very intense leg weight training will always result in better results.
HIIT has been shown to increase metabolism greater than aerobics and in a lot less time. So if you have mixed goals (add muscle, lose fat) then it makes sense to do intervals instead of aerobics.
On a tangent, HIIT gives the legs a very intense workout. If you’re already working out legs regularly this might dampen leg development due to overtraining. I wonder if over the mythical “long run” someone would be better off trying to add as much muscle as possible (each pound of muscle increases BMR by what, 40 calories?) and not bother with all this heart rate mumbo jumbo. Just a thought…
-Josh
23 greenman2001 // Mar 20, 2008 at 6:02 pm
Josh,
Thanks for clarifying. How does cardio cause atrophy? What’s the mechanism at work?
24 Leah // Mar 27, 2008 at 5:44 pm
I realize I’m a bit late, but I want to comment on the rationale behind interval training. Have you ever read anything about “tabata intervals” or “high-intensity interval training”? The idea is that you push yourself to do some work in the anaerobic zone. Gains in the anaerobic zone actually translate into aerobic gains as well, and there’s research that shows that VO2 max increases with anaerobic training. Anyway, go read about it — it’ll tell you more than I can. But that’s the idea behind interval training.
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