Tour-de-France vs. quickie workouts: Which is better?
March 19, 2008 12:02 PM   Subscribe

1 hour workout vs. 3 hour workout... which is more effective for weight loss and weight loss only? A friend and I are unable to agree.

We all know the key to weight loss is, more calories burned than consumed, correct? A friend of mine, who has lost 100 lbs. in a year, asserts that you NEVER should do more than an hour of cardio and that HIIT workouts (20 minutes or so) three times a week are even more effective than a regular hour, say, on the elliptical. He also asserts that working out any more than that will do nothing for you.

I say, well, if you eat 1600 calories in a day, and work out for three hours, burning 1000 calories or more (say, rowing machines, walking, alternating jogging and walking, stationary bike, etc.), you will have a 1000 calorie deficit and your body will only have 600 calories to run on, assuming you are vigilant and not making assumptions about the total calories burned. I also am asserting that professional athletes can work out up to 6 hours a day, 7 days a week, so if you are in shape, the time dedicated should not be an issue.

Assuming you eat every four hours except while sleeping, and are performing mostly cardio with weights and toning exercises (lunges, squats, pushups, free weights) thrown in every other day, and your only goal is to lose weight... why wouldn't taking the time to burn more calories be BETTER for weight loss? Is there some magical point at which this stops working?

My doctor AND a nutritionist have both told me that cutting below 1200 calories per day will put my body into shock. Exercise, from what I can see, is the only way to raise my calorie deficit. However, there has been much debate on MeFi whether or not exercise can truly impact weight loss. Please help me understand this better.

Personal aside: When I wanted to maintain my weight, I worked out an hour every day and was perfectly happy with that. My weight never went any lower. I have been working out regularly for at least eight years and am in reasonably good shape; I am not proposing to work out to the point of injury, only to the point of a significant calorie deficit.
posted by Unicorn on the cob to Health & Fitness (23 answers total) 9 users marked this as a favorite
The truth is probably somewhere in between. Cardio / aerobic exercise burns fat only while you are exercising. However, anaerobic exercise (weight training, HIIT) continues to utilize fat for a long while after the exercise. This is particularly true when exercising large muscle groups (quads, chest, etc.).
posted by detune at 12:06 PM on March 19, 2008

It's going to be impossible to answer this definitively - I'm afraid it really is a situation where your mileage is pretty much guaranteed to vary, as far as what's optimal for you. Your friend's "...any more than that will do nothing for you" isn't completely accurate, but it's subtler than the "I had freshman physics" crowd will admit, because your exercise and eating habits can change the basic rates at which your body uses calories... but that's quite a rabbithole to start exploring. Your friend's theory is probably based on the idea that you can sustain high intensity for a short time without taking in any nutrients during the exercise, and your elevated heart rate persists for some time afterwards; there's energy used during the cool-down and recovery periods. Doing really high-intensity aerobic work for longer periods, he'd say, is somewhat of a wash, because you simply can't sustain it without taking nutrition as you go; your body's stores won't get burned fast enough to support it. On the other hand, if you keep it slow enough that you can sustain the effort without needing to take in food as you go, then you're probably right that you continue to get benefits more or less in proportion with the time spent. (Counterpoint from your friend, presumably, is that "most" people are more likely to find time for, and stick to, the short high-intensity schedule than a lower-intensity regime that requires three hours a day. That's one way that your personal taste and circumstances start to creep in to the calculation.)
posted by Wolfdog at 12:14 PM on March 19, 2008

I think the studies about HIIT are pretty compelling, although I'm not sure why the HIIT itself would have to be time limited. I will say, as someone who regularly runs 1.5-5 hours five days a week, that it's quite hard to lose weight just by upping the amount of cardio. I think there are several reasons for this, with the release of stress hormones like cortisol prime among them. (Even restricting my calories to around 2500/day doesn't result in rapid or sustained weight loss for me, and according to the numbers, it should.)
posted by OmieWise at 12:15 PM on March 19, 2008

Yeah, for weight loss, an hour of cardio is more than plenty but you also have to do weight training.

Building muscle burns calories around the clock, while cardio trains your system to use fat as fuel.

Anyhow, truth is, if you watch what you eat and you exercise, you will lose weight. Lather, rinse, repeat.
posted by konolia at 12:22 PM on March 19, 2008

Best answer: I believe the high-intensity interval training (HIIT) studies demonstrated increased fat loss vs. training that did not vary in intensity throughout a session. They also showed more fat loss in a shorter session than a longer, non-variable intensity workout. Perhaps this is what your friend is thinking of?

Anecdotal evidence: I run marathons and, in addition to daily runs of approximately one hour, do long runs once per week that last two or more hours. These are not interval runs. I struggle to keep enough weight on during marathon training. I get a bit bony. So I believe that you are correct, in terms of my personal experience. The more hours I run, the more weight I lose. (Again, this is n = 1, and I am convinced that there are idiosyncratic differences in the effects of eating and exercise among individuals.)
posted by frumious bandersnatch at 12:42 PM on March 19, 2008

Best answer: I think you'd be shocking your body into something similar to famine mode by working out this much. During a famine, your body's metabolism will adjust to make the most out of every calorie, and won't burn them as readily. The same would seem to be true for working out a lot while simultaneously seriously cutting back on calories. Basically what you're doing is training your body to subsist on fewer calories, which is not the point. What you want do is essentially the opposite. You want train your body to burn calories like there's no tomorrow, so work out hard, and eat well, otherwise, you may be training your body to store fat whenever it gets some because you will essentially have trained it to behave as though these might be the last fat it will see for a while. This is why some people yo-yo. Some people have actually trained their bodies to store fat quicker than others.

My trick is to eat sensibly and work out a consistently, but not to over do it. If you're hungry, eat. If you just have a carb addiction craving, try to hold out. As far as exercise, it's not only the length of time but also the heart-rate that matters. You might be working out for three hours, but if you're not monitoring your heart-rate to make sure it stays in the 120-135 bpm range for 25 to 30 nonstop minutes, then you're not in weight-loss mode. You're not accessing your body's stored energy in the form of fat, but rather, you're burning caleries from sugars in your blood stream. The best way to lose weight is to get into that sweet heart rate range 4 to 6 days a week using a variety of exercise techniques, and not just the same one day in and day out. From my point of view, less is more, because you don't want to put your body in famine mode. I'm skinny, so I think I might be on to something.

I guarantee you that if you really truly keep your heart rate in the range I've said and don't stop for 30 minutes, you'll be pooped! You won't have it in you to do 3 hours. Remember, the best approach to weight loss is lifestyle change. Make changes in your diet and exercise routine that you can stick to for the rest of your life. I don't see you working out 3 hours a day 6 days a week for the rest of your life. I don't see anybody doing that. I would say you'd be putting yourself on a path to yo-yo weight gain by doing so.
posted by tosteka at 12:45 PM on March 19, 2008 [5 favorites]

It's more complicated than either or. Cardio burns calories. Strength workouts burn calories. Increased muscle mass also makes your body burn more calories at all times--while you are exercising and while you aren't.

He also asserts that working out any more than [an hour of cardio] will do nothing for you.

why wouldn't taking the time to burn more calories be BETTER for weight loss?
It is. More time doing cardio does mean more calories burned. I certainly burned 3 times as many calories on a Saturday long run of 15 miles than a weekday run of 5 miles.

But you can also improve your calories burn with strength training, which I think you know, so your friend's theory is not baseless. Muscle burns more calories than other body tissue, so having more muscle increases your basal metabolic rate--and this state persists during all activites. So, if you increase your muscle mass the way you described (lunges, weights, etc), you increase the calories you burn while doing cardio, too. In no way does that mean that cardio is time or quantity limited in its usefulness, it just means it's complementary and a balance is they key.

there has been much debate on MeFi whether or not exercise can truly impact weight loss
Exercise definitely can impact weight loss. But I think most people find that controlling calorie intake is more effective for weight loss than exercise (especially exercise alone), but that's not because of a physiological situation, it's because of the relative time and effort required for eating v. burning caloies. For the most part, calories in v. calories out is the answer. If you eat fewer calories than you burn, you will lose weight. And you are correct that working out for three hours will burn a lot of calories.

But how many people have the time or energy to work out three hours a day?

Also, people:
--are very hungry when they work out that much
--"reward" thenelves with food after working out a ton (or think they can eat anything they want because they ran 5 miles--which is like one muffin's worth of calories)
--underestimate calories eaten

So people think, "damn, I worked out all that time and I STILL haven't lost weight." But a bagel here, a latte there, and you've obliterated the deficit. It's very much easier to eat two extra pieces of pizza than run 5 miles.
posted by Pax at 1:00 PM on March 19, 2008

I can't find a cite offhand, but I read somewhere recently that the commonly held idea that the additional calories burned by muscle is somewhat negligible.
posted by electroboy at 1:28 PM on March 19, 2008

Well, this just goes to show you how complex this is. fruminous bandersnatch and I seem to exercise in similar ways (I'm also a marathon runner although also longer), and we have opposite problems.
posted by OmieWise at 1:38 PM on March 19, 2008

Response by poster: Wow, so many differing personal experiences! I guess it may, just MAY, come down to the individual. I'd probably be better off eating dinner earlier and just walking on a treadmill while watching TV vs. killing myself at the gym, based on some of the stuff I'm reading here... all good points, everyone! thank you for so much varying input!
posted by Unicorn on the cob at 1:49 PM on March 19, 2008

Yes if you exercise more you will lose more weight, more rapidly. It really is just calories in and calories out. Your doctor and nutritionist are simply wrong about 1,200 calories however. I have lost lots of weight on Doctor-supervised diets with as little as 520 calories. These so-called liquid diets are not very fashionable now, and I personally found that I seemed to get better results if I consumed 700 calories/day, with a lot of exercise, but I can tell you that most definitely you will not go into "shock" with less than 1,200 calories/day. Not unless they mean by "shock" that you get very irritable during the day and start dreaming about food at night. :-)

It is however true that people who go on fasting diets do tend to gain the weight back, but I believe this is because people who lose weight tend to gain it back. It's really really hard to keep weight off, for people who like to eat. I'm pretty much just resigned to going on diets to lose weight every year or two, no matter what I do.

I believe that people who make a living at being thin and fit work out many hours per day. That's my impression of how movie stars stay fit. You might want to look at what Oprah Winfrey does...
posted by thomas144 at 1:50 PM on March 19, 2008

Response by poster: Well, working out for an HOUR at the gym and spending more time doing low-impact stuff, anyway. I have been sort of killing myself at the gym and don't want it to end in injury.
posted by Unicorn on the cob at 1:54 PM on March 19, 2008

Anecdotal vs scientific, but I recall reading about a magazine editor who, instead of his usual 25 mile ride daily, commuted -12 miles each way. His weight plummetted. The tail-off after the workout was effectively doubled.

Personally I sometimes do days where I swim before work, run at lunch, and ride after work. Total calorie output ~2000cal, but I swear it drops a pound - long term - every time I do this.
posted by notsnot at 2:02 PM on March 19, 2008

Response by poster: ahh, notsnot. Maybe working out twice a day in small bursts would help! That's a good idea...
posted by Unicorn on the cob at 2:03 PM on March 19, 2008

I believe it also takes at least 20-30 min each time to be effective.

And if you think about it, it's not a HIIT/weights vs regular cardio thing: after a workout, your pulse, metabolism, everything, are elevated for some nontrivial period of time. If you have that extra burn twice versus once, even if you assume the tailoff is a rather short period of time, it's something.
posted by notsnot at 2:07 PM on March 19, 2008

You and your friend are having the wrong argument. Research has found that 1 hour of HIIT is more effective at burning calories and maintaining fitness than 1 hour of moderate intensity exercise. The key part is that you're doing the exercise for the same amount of time, but at different intensity levels. I don't know what the exact breakdown is, but consider that the intensity level you could maintain over 3 hours is a lot less than the maximum intensity you'd reach doing HIIT.
posted by !Jim at 2:20 PM on March 19, 2008

Doing HIIT for an hour, that is.
posted by !Jim at 2:21 PM on March 19, 2008

I just wanted to add something. I watch the show The Biggest Loser and have read about what they do with the contestants there. They help the contestants eat low calorie (but not extremely low calorie) diets. The main thing they do there is that the contestants do low intensity aerobics for about 6 hours a day and about 1-2 hours of higher intensity workouts each day. Obviously, based on the results on the show, this works (although it appears like with all weight loss, it works better for men than for women). On the current season of the show they are about 10 or 11 weeks into it, and the contestants have all lost at least 60 pounds, with some well over 100 pounds in 11 weeks. So in my opinion, it is obvious that working out more will burn more calories.

The issue for most people is that they don't have 8 hours a day to exercise, so they want the biggest bang for their exercise buck. In this case, HIIT seems to be the clear winner according to the recent research evidence. (The Biggest Loser trainers swear by it for the intense part of their workouts as well).
posted by bove at 2:40 PM on March 19, 2008

Best answer: although I'm not sure why the HIIT itself would have to be time limited.

HIIT is self-limiting. If you can do HIIT for more than about 20 minutes, you are not doing HIIT, you are doing interval training. Which is great, but it isn't HIIT.

I think that the suggestions to work out more often in bursts are probably right as far as pure weight loss goes, especially if you mix up the activities. Your body is extremely good at getting efficient at any one exercise, and your calorie burn drops sharply if you do not push yourself constantly. Let's not forget that athletes, people on The Biggest Loser, and people who must be fit for a living are not just strolling on a treadmill for a few hours a day. They are being pushed by their trainers and are very invested in their workouts. If there is one thing you can learn from them, it is that you should view every workout as something you are really invested in.
posted by ch1x0r at 4:54 PM on March 19, 2008

I think you're missing the entire point. Diet, not exercise, is more important for weight loss. Yes, it's important to exercise frequently, because this keeps your body healthy, but diet is what regulates weight gain (or loss) more than anything else. The reason I can say this is clear: You can exercise vigorously for an hour and only burn off around 500 calories. Yet, you can eat a burger at Carl's Junior and intake 1500 - 2500 calories in one sitting (when you add fries and a soda).

I would recommend you read Eat Right 4 Your Blood Type. You might be eating foods that promote weight gain, even when you're working out a lot. This throws a monkey wrench in many people's programs, as they sabotage themselves by eating foods that aren't beneficial for their blood type.
posted by noir at 12:21 PM on March 20, 2008 [1 favorite]

Response by poster: Well, considering I'm working with a doctor and a nutritionist... and weighing/portioning my food exactly, I don't think that's it. Unless eating a meal consisting of 5 cherry tomatoes, 4 oz. of lowfat cottage cheese and one small organic apple is making me fat?

I gave up junk food over a year ago.
posted by Unicorn on the cob at 2:37 PM on March 20, 2008

Anyhow, truth is, if you watch what you eat and you exercise, you will lose weight. Lather, rinse, repeat.

Truth is most people could simply eat better, skip the exercise, and lose weight. Lather, lather lather.
posted by gtr at 9:47 PM on March 25, 2008

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