Rethinking Exercise And Weight Loss

Exercise is great for your health, but it doesn’t do much for weight loss.

I’ve said it. Plenty of people I respect have said it. You might have said it. But based on recent experience, I’m not so sure it’s true.

That is, of course, what the research suggests. In my Science For Smart People speech, I mentioned a study in which middle-aged women were enrolled in a pretty intense aerobic exercise program: 45 minutes per session, five sessions per week. According to the published study, compliance was quite good. Women in the exercise group average 3.6 sessions per week. That works out to an average of 162 minutes per week.

And yet after a year, these women had lost an average of a whopping 4.4 pounds of body fat compared to a control group of women who didn’t exercise. Hardly a ringing endorsement of exercise as a fat-loss tool. (I mentioned the study in the speech because the researchers touted the results as proof that exercise is good for weight loss. Seriously? A year’s worth of effort to lose 4.4 pounds of body fat?)

The scientific literature is full of similar studies. People enroll in exercise programs, put in the time and effort, but lose very little weight.

And yet I have to balance that against my own experience. Exercise does seem to accelerate weight loss for me. I just proved that to myself again recently. Well, perhaps proved is too strong a word, so let’s just say I have n=1 evidence I find compelling.

For the past several years, my weight has generally hovered around the 200 mark. In the summer I’ll typically weigh 197 pounds or so, and in the winter I might weigh more like 202. I fattened myself up during the 2016 holiday season by indulging in too much good scotch and good food, but lost the extra bloat once I went back to my usual diet.

Then came the surgery in November. I didn’t think I’d gain any significant weight during the long recovery, but I did. A big part of that was diet. I’d been cut open, had bone shaved away, and had a torn tendon re-attached. I didn’t want to be in a catabolic state when my body was trying to rebuild damaged tissues. So I ate rather freely, including more potatoes and other starches I’d normally limit. My physical activity, of course, went down to zero after the surgery.

We don’t have a scale at home, so the first time I weighed myself was in January, when I went to the gym just to work my legs. The scale said I was at 213 pounds. Yikes.

I tightened up the diet, went back to limiting the carbs to somewhere in the 50-75 gram per day range, watched my portions, fasted until dinner two days per week, limited my alcohol consumption to two beers on Friday night, etc. Yeah, that should do it.

Six weeks ago, I went to the gym to work my legs and stepped on the scale. I was at 212 pounds.

What the f…? I tightened up my diet for nearly six weeks and lost one pound?! Well, that’s just awesome. At this rate, it will only take me until sometime in 2019 to be back to what I consider my normal weight.

When I was hitting the gym regularly and putting in farm-work sessions on weekends, that same diet kept me at or below 200 pounds.  I wasn’t cleared yet for lifting weights or doing heavy outdoor work, so I made one additional change to my routine: I started diligently using the treadmill I bought myself after the surgery. This one:

For the past six weeks, I’ve been putting in hour-long walking sessions four or five nights per week. I actually find them quite pleasant. The treadmill has a little shelf to hold a tablet and a connection jack to built-in speakers. I watch documentaries on my iPad while walking (the latest is Wild Wild Country on Netflix) and the hour goes by quickly.

I had my final follow-up session with the surgeon a few days ago and finally got clearance to do full workouts at the gym again, with a few caveats: 1) start at half the weight I used to lift on all upper-body machines, 2) don’t go to a higher weight until I can do 15-20 reps with good form, and 3) don’t ignore pain and try to work through it.

Yeah, okay, I’m fine with those. I’ll turn 60 in November and have had my shoulder surgically repaired twice now, with a bicep surgery and a knee surgery tossed in for good measure. I shouldn’t expect to work out like a 25-year-old jock.

On Sunday, I went to the gym and worked my upper body for the first time in six months. The bad news is that I’m a lot weaker than before the surgery. I thought dropping to half the previous load would make each exercise seem ridiculously easy, but, uh, no. It was real work.

The good news is that when I stepped on the scale, I weighed 205 pounds. That means I’ve lost seven pounds in six weeks – on the same diet that previously produced a one-pound weight loss in a similar span. The only difference I can see is the time I’ve been putting in on the treadmill.

Keep in mind, I’m not suggesting it’s a simple matter of calorie math. In fact, the usual calorie math doesn’t account for it. The treadmill has a feature that displays how many calories you burn during a session based on your weight, the incline, the speed, the distance, etc. If the feature is accurate, I’m burning around 300 calories per session. At five sessions per week, that would translate to 1500 calories, or less than half a pound. But I’ve lost just over a pound per week.

Back in my low-fat, high-carb diet days, I jogged for lord-only-knows how many miles and spent countless hours on treadmills, but never lost any significant weight. If it were a simple matter of losing weight by burning calories through exercise, I should have gotten leaner. But I didn’t.

So why do I believe exercise is working as a fat-loss tool now, when it failed me before and has failed so many times in clinical research? I’m just spit-balling here, but I think it probably comes down to hormones.

To explain, I’ll quote from the Fat Head Kids book. In the chapter on why we get fat, we introduce Marty Metabolism, the chief engineer for the biological starship known as The Nautilus. Getting fat, we explain, is the result of Marty receiving commands delivered by chemical messengers called hormones:

Since Marty is under orders to store more fat, he’ll trigger the Get Hungry! program to make you eat more. But if that doesn’t work, he’ll slow down your metabolism to burn less fuel. Either way, you end up consuming more calories than you burn … The commands from hormones are so powerful, Marty can’t just ignore them.

Trying to lose weight by burning calories through exercise is just the flipside of trying to lose weight by eating a bit less. Both assume your body works like a simple bank account, with your weight determined by the simple math of deposits vs. withdrawals. Cut your calories by 500 per day, and by gosh, you’ll automatically lose half-a-pound per week and all that.

But of course, our bodies are nowhere near that simple. Marty has to be willing to go along with the plan. Otherwise, he’ll respond to that attempt at creating a calorie deficit by slowing your metabolism to match the lower food intake.

When I used to go jogging for miles, I was still eating a diet that commanded Marty not to burn away stored fat. So he didn’t. I suspect that in many of the studies on exercise and weight loss (or lack thereof), the subjects were also consuming a diet that worked against burning away stored fat.

But suppose we switch to a diet that tells Marty, through a change in hormonal signals, that it’s perfectly fine to tap the fat stores. Now eating less works. Now exercising works.

And of course, the right kind of exercise also affects the hormonal balance. It improves insulin sensitivity, to name just one benefit. To name another, I’ll quote from the excellent book Primal Endurance, by Mark Sisson and Brad Kearns:

Exercise not only increases the size and number of mitochondria, but also makes them more efficient by increasing the number of oxidative enzymes found in mitochondria. These enzymes improve metabolic function of your skeletal muscles, boosting fat and carbohydrate breakdown for fuel, and speeding energy formation from ATP.

Dr. Bill Lagakos, author of the poor, misunderstood calorie, has also written about how walking lowers fasting glucose and fasting insulin levels.  (I believe you have to be a Patreon of his site to read the full article.  If you’re not a Patreon, I’d urge you to become one.  He puts out a heckuva lot of good material.)

Exercise suppresses insulin via sympathetic nervous system. This doesn’t matter because a contracting muscle, or rather the contraction itself, recruits GLUT4 to the surface of contracting muscle to suck up glucose, to fuel the contraction. It doesn’t need insulin to do this. Glucose-lowering this way also contributes to reduced need for insulin. This is a very healthy thing.

As Sisson and Kearns emphasize in their book, crappy foods can easily cancel out those benefits. That’s why there’s an entire section on diet in what’s otherwise an exercise book.

But if you don’t cancel them out, the benefits are real. I’m pretty sure that’s why I’m no longer stalled on losing the post-surgery fat.

Add it all up, and I’m not sure we’re doing anyone any favors by insisting exercise doesn’t do much for weight loss. Combined with a diet that creates a favorable hormonal mix, perhaps it does. It sure seems to be helping in my case.

But that’s my n=1 experience. I’d like to hear how exercise has or hasn’t worked for the rest of you.


68 thoughts on “Rethinking Exercise And Weight Loss

  1. js290

    CI affects CO and vice versa. They are mathematically coupled and cannot be treated independently as calorie counters like to do.

    1. Tom Naughton Post author

      Definitely not like a bank account. Maker bigger deposits in your bank account doesn’t cause your spending to go up.

      1. js290

        For some people, bigger bank deposits does cause spending to go up! 😛 Those people probably don’t retire early, though. 🙂

    2. Björn Hammarskjöld

      There is another small problem. The second law o thermodynamics. The efficiency is always less than 1. And a cell can regulate efficiency between 50 to 0 percent efficiency. By uncoupling the phosforylation in the mitochondria of brown fat the cell does’nt make ATP or fat out of sugar but heat. And we usually don’t measure heat expenditure.
      So by regulating the efficiency you can eat the same amount of food and go up or down in weight.
      So our bodies are much more complicated than we think and there are very many parallell metabolic pathways leading from A to B. And the body really always choose the best way to the survival of the body.
      Then we have a problem with the non essential macronutrient carbohydrates. As the carbohydrates art very toxic but we do need about 1.5 to 3 grams of glucose in the blood volume of 5,6 L (about 12 US pint) for powering RBC and release of oxygen from hemoglobin. More than 25 g glucose in the same amount of blood is a cause of acute death due to glucose overdose. Then the authorities recommend me to commit suicide by recommending me to ingest 480 g (1.06 lb) of glucose per day. It’s a twentyfold lethal dose of glucose per day. So I thank Nature to provide such a good defence against the authorities’s recomendations so I do survive every day. So by eating a low carb diet I’ll survive longer.

      1. js290

        Yep, the other assumption calorie counters make is we’re 100% thermodynamically efficient. If that were the case, we’d never have to use the bathroom…

        After learning about some of the metabolic cycles, I ask the question to calorie counters, “which metabolic cycle biochemically uses calorie (heat) as a substrate?” But, someone else points out we probably convert some solar energy into ATP through the skin.

  2. Jeff

    I’ll give you another n=1 example: my wife. She can eat low carb, high fat for a month and lose no weight. But as soon as she starts doing something as simple as walking for 20-30 minutes/day, the pounds come off pretty quickly. So it’s not just you!

    As an aside: we are now residents of the state of Tennessee! Down the Chattanooga way, but TN is now home! Looking forward to exploring this beautiful state!

    1. Tom Naughton Post author

      So I’m not the only one.

      I think you’re going to love it here. Beautiful scenery and nice (mostly) people.

  3. Tom Welsh

    I completely agree, Tom. Ever since I took up Palaeo and then LCHF – maybe ten years ago – I have been gnawed by uncertainty about the extraordinary claim that “exercise doesn’t reduce weight”. Having been interested in athletics (track & field) and other sports since the 1950s, I am of course familiar with the stories of many people who lost dramatic amounts of weight through running. There are exceptions to the rule, one of which I think is cited by Gary Taubes in one of his books. But then there are people who sink when they try to float in water!

    For just one spectacular example, read “Bill Bowerman and the Men of Oregon” or any other account of Bill Bowerman’s life. When he led a USA track & field team to tour New Zealand in 1961 (from memory) Bowerman was a typical American coach of the time – middle-aged, fat, unfit, and with a heart condition. He stood by the trackside and shouted exhortations as the runners sped by, but never thought of joining them.

    Bowerman’s New Zealand opposite number was Arthur Lydiard – coach to Murray Halberg, Peter Snell and other stars. A shoemaker by trade and an amateur coach, Lydiard had run many marathons (and further). Every Sunday morning he led his athletes on a run through the Waiatarua hills above Auckland – 22 miles, but reputed harder than a marathon because of the rise and fall.

    On their first day together, Lydiard invited Bowerman to join him and some fun runners for a jog. Dubiously, Bowerman agreed, only to find they went three miles and three miles back! When he returned to the USA weeks later, Bowerman was already much leaner and fitter, and went on to initiate the great spread of popular marathons and fun runs across the USA. He lived a long life, and was apparently not troubled by his heart.

    Members of my own family have shed a stone or two after starting to run regularly. It stands to reason. I think people who believe exercise does not lose weight are not thinking of enough exercise. Walking 20 miles a day, or running 10-15 miles, will definitely change one’s shape and health. And that is probably what our ancestors evolved to sustain.

  4. Emily

    Exercise absolutely helps for me. Since I haven’t been able to exercise, I haven’t been able to drop weight at all, when previously it was pretty easy to drop a few pounds solely through exercise. (Swimming and weights, btw.) I’m not sure my n=1 experience is very valuable for others, though, because my recent weight gain was due to a combination of prescription opiates and eating very little. I stopped gaining once I started eating enough, and then dropped a little when I stopped the meds, but I’m pretty much stuck now.

    1. Tom Naughton Post author

      if opiates trigger weight gain, that might explain part of my post-surgery flab. I was on Percocet for the pain.

  5. Kathy in OK

    “and nice (mostly) people” vs. “and (mostly) nice people”

    Somehow the first phrase makes me think the residents are not all people – LOL. But maybe you were including the deer, turkey, raccoons, etc.? And your dogs, cat and chickens? Maybe the first phrase was more accurate. Love your writing, either way.

      1. Walter

        Deer make a better and easier to clean and cook than deer. On the Gripping Hand deer carry diseases and are quite a pest for gardeners.

        Raccoons are if not exactly smart crafty.

      2. Dianne

        There’s a good reason raccoons wear those little black bandit masks. It’s because they’re bandits. Cute and clever, but bandits.

        1. Tom Naughton Post author

          I found them far less cute the first time I approached one I’d trapped and he hissed and snarled and raged at me. Then I saw the chicken-killer, which made it easier to pull the trigger.

  6. Nick S

    I’ve tried many combinations of diet and exercise over the years, and it basically works out to this for me:

    – Strict low-carb dieting (<30g/day) w/o cheat days, no exercise: maximum weight loss speed – the scale weight PLUMMETS – but I feel "flabby" and not great.

    – Strict low-carb dieting w/timed carb refeeds, regular exercise (lifting & cardio): slower weight loss, but I look and feel better.

    – Clean eating w/limited carbs (<100g/day), regular exercise: no weight loss, but I can "body recomp" doing this where weight stays the same but I get visibly more muscular. Maximum performance gains in the gym.

    – Dirty eating w/no carb restriction, regular exercise: Get stronk, but also get fat, slowly. Not surprising.

    – Dirty eating w/o exercise: That whooshing sound you hear is the air being displaced by my fat gain.

  7. BobM

    This just shows you how little we understand and how complex the body is. I have found that if I exercise a TON, by this I mean 100+ miles a week on a bike, I could lose weight. However, I got less hungry. I think it was hormonal, meaning I was changing my insulin response. Of course, when summer was over, and I no longer had or could exercise that much (much harder to exercise in freezing temperatures), all that weight came back on.

    I had shoulder surgery and got concerned when my weight was going up post-shoulder surgery. Why? I’m sure some of it was building muscle, but it freaked me out to the point I went and got a DEXA (dual energy X-ray absorptiometry) scan, which measures body fat and muscle. I’m about to get my second one.

    In my mind, I’m still not clear about exercise and weight loss. For instance, if walking lowers blood sugar and insulin, why wouldn’t jogging/running/cycling? Is one better than another? Does walking cause less hunger for some reason? Or is it only when you combine exercise with low carb dieting (or another low-insulin load) that’s helpful?

    What about a low carb diet and Omega 6 fatty acids? Petro Dobromylskyj ( has a theory that saturated fat causes fat cells to become insulin resistant (good in this case), whereas Omega 6 fatty acids cause them to be insulin sensitive (bad in this instance). That is, if you eat a diet high in Omega 6 fatty acids, you cause your fat cells to become insulin sensitive, leading to weight gain and likely increased calories (no feedback mechanism to stop eating). So, one could set up two low carb diets, one with low Omega 6 fatty acids, and one with high Omega 6 fatty acids, and the latter low carb diet could fail while the former one might not.

    Then add in the protein debacle to this: some think high(er) protein is good; some think low(er) protein is better. I’ve been testing higher protein, and I know my blood sugar is not bad at all on it, but I can’t test insulin or anything else. I think higher protein = longer feeling of fullness, but it’s difficult to tell.

    I have always exercised, many times 4+ days per week, and still gained 100+ pounds. I reduced my carbs and my exercise and lost 30 pounds. I added intermittent fasting to that and lost another 20+, then had shoulder surgery, which also causes massive muscle loss (can’t lift any weights for weeks, then less than 10 pounds for many months, very difficult to exercise at all).

    Anyway, the problem with an n=1 study for me is that I never eat the same. This and last week, I fasted or will fast 36+ hours, twice a week. Next week, I will not fast at all (other than not eating breakfast). I’m currently eating a ton of hard boiled eggs (Easter, coloring), which are higher in Omega 6. I’ll eat less chicken this week (higher in Omega 6), and more beef (lower in Omega 6, at least for grass-fed). I currently exercise twice per week, about 25-30 minutes Body by Science lifting plus HIIT (High intensity interval training) on a bike, only 10 minutes or so, for about 40-45 minutes. I continue to lose weight and gain muscle, even though I reduced my exercise from 4 days, 45+ minutes/week (lower intensity) to two days per week.

    Ideally, in a study of whether walking (or some other exercise) would help with weight loss, I’d have to change one thing, the exercise, while keeping what I eat exactly the same (perhaps letting calories float). And that never happens. Even if I’m eating beef, I don’t eat the same thing per week. This week, I’m eating liver and lean steak (and lots of eggs). Next week, probably beef heart, then I go on vacation, and will partake of some ice cream and maybe even pizza (which I know is very bad for me — causes a horrible blood sugar response, but tastes good). So, it’s very challenging to determine the effect of exercise on weight loss, unless exercise is the only variable changed. For me, that’s tough to do.

    1. Tom Naughton Post author

      It’s certainly complex, and I don’t think we have anything close to all the answers. I suspect jogging and cycling would induce weight loss in people IF they’re in a hormonal state that allows easy access to stored fat. A bad diet could prevent that hormonal state, which is what I believe was happening with me back when jogging did little for weight loss. As a “healthy” person, I was limiting fat and eating lots of hearthealthywholegrains. But again, I’m only speculating.

  8. Wayne Gage

    I smoked my last cigarette about fourteen years ago…I was up to two packs a day and I knew it was wrong so one of the ways I would cut down my smoking is riding a bicycle.. You can’t easily smoke and ride at the same time. Before Fat Head to cut down on my eating I would walk for an hour…it’s hard to eat and walk at the same time. Now, hoping for warmer weather I’ve started walking everyday it doesn’t rain. About an hour in the morning. I should be down to my summer weight in about a month.

  9. Kathy in OK

    I’ve pretty much given up losing more than a few pounds here and there. Years ago I did Weight Watchers and became a gym rat. Over time, I went from 220 to (briefly) 150. I was driven, but all I thought about was food. When that drive suddenly left me – I don’t know why – I gained back about 20 pounds and stabilized at around 170. I’m 5’5″ but have always carried my weight all over, not just a big butt or belly, so most folks are surprised at my scale weight. Anyway, at the age of 70 and 164 pounds, I’m now more interested in eating healthy and exercising for strength and flexibility. So I have a Total Gym (upper body strength), a great little exercise bike (1 hr of cardio a day) and an old step (remember step aerobics?) to work on legs for climbing stairs and strengthening around the knees. I don’t intend to live forever, but if there’s any fairness in this world, I won’t be a burden – financially or emotionally – to anyone I love. That’s my story and I’m sticking to it.

    1. Kathy in OK

      That was a bit long, but I should clarify “eating healthy”. Let’s see, something of a low carb (most days) Whole 30 with dairy. Not much in the way of processed foods, but I do participate in family gatherings for birthdays and such – a bite of cake and ice cream won’t kill me. I try to be flexible enough to avoid being a weirdo outcast, since it’s the husband’s extended family.

    2. Tom Naughton Post author

      I’m sticking to that story too. I don’t plan to live forever, but I want to be strong and mobile for as long as possible.

  10. Marty B.

    I’m glad to see you come around a bit on this Tom. I know several years ago (and even still today), plenty of LCHF guru’s proclaim that you don’t need to exercise. Any weight loss plan that tells you that you don’t need to exercise is going to sell better. Fact is, there’s no reason that people can’t simply use walking as their form of exercise. I personally run, but realize that as I get old that will be less and less of an option. I can’t lose any weight unless I exercise. As for my n=1, I lost roughly 100 pounds (6’4, 320 to 220) by running 15-20 miles a week, and counting calories. I realize that counting calories doesn’t work for everyone, but exercising should. It should be noted that, especially with aerobic exercise, it can end up making you hungry and cause you to eat more than you normally would, cancelling out the calorie burn. The best solution to this for me was to find a good time of day to run where you get more of a runner’s high when you’re done instead of a “lay off me I’m starving” feeling. Or time it so when you’re done, it’s time for a meal anyways (just don’t overeat).

    I wish Jimmy Moore would come around too, instead of trying more crazy experiments. There are very few excuses as to why someone can’t get their exercise via walking.

    1. Tom Naughton Post author

      I think of lot of people (myself included) decided exercise wasn’t a good weight-loss tool back when we were eating foods that canceled out the benefits. I jogged many, many miles without shedding any noticeable body fat, so of course the “exercise doesn’t cause weight loss” statements made sense to me.

      1. Meg Johnson

        I agree. When I was 33 I did the training for and ran a half marathon. Ate carbs/SAD as always. Lost little if any weight (15 years ago, so I don’t remember the specifics, but remember thinking “how can I be running this many miles and not lose weight?”)

  11. j

    If the diet is right, exercise definitely helps burn fat. Weight training, obviously, is great for muscle building and strength. And I prefer a moderate intensity outdoors approach for cardio. Much more enjoyable and I think productive compared to long high intensity routines. This is probably very similar to Sissons Primal model.

    1. Tom Naughton Post author

      Yup, that’s more or less what he recommends. Specifically cardio that keeps your heart rate around 180 – your age.

  12. Lori Miller

    I had a recent experience where I was so sick I barely ate anything and mostly laid in bed for a couple of days. Weight loss: two pounds in five days’ illness. I can normally drop five just by not eating restaurant food. Oddly enough, I had bad acid reflux while not eating.

  13. Kayla Hunt

    This is a very timely post for me. I got back to LCHF about a month ago, and stalled out after the first week. I love all the other benefits of LCHF, but I also need another 50lbs to come off. Now that we’re out of the deep freeze up here in the great white north, I’m going to add walking to my day, I’m pretty sedentary in the winter. The first time I tried LCHF, 6 years ago, the weight just fell off, to a point, then I gave up and slid back into old habits. No giving up this time, so lots of n=1 experimentation in my future 🙂 Intermittent fasting, no artificial sweeteners, possibly giving up dairy – we’ll see.

  14. Mike Brady

    To my shame, I don’t have a regular exercise routine. I just squeeze different types of physical activity here and there — sometimes regularly, oftentimes not so regularly. I have noticed two things, however:

    1) When I’m doing a fast of 16/8, 24, or 48 hours, if I get the munchies, doing a *small* amount of exercise or physical activity makes the hunger go away more quickly.

    2) The thing I notice on the scale is that when I am exercising more regularly, especially body weight and dumbbell exercise 1 or 2 times each week, I sleep much more soundly. When I get more and deeper sleep, my weight trends downward. When I don’t get enough sleep or it is poor quality, my weight inches upward.

    So, I wonder how much better sleep might be a factor for weight loss when including exercise.

    1. Tom Naughton Post author

      Good sleep certainly helps, but my sleep schedule was the same when I was and wasn’t doing the treadmill sessions. Those sessions seem to be the only variable that’s changed in my case.

  15. Kathy in OK

    Last October I was really sick for a couple of weeks. Then two more weeks to regain the ability to get through a normal day without some rest. Dr. Google and I are pretty sure it was viral pneumonia – progression, symptoms, temperature, etc. all pointed to that diagnosis. I mostly slept in the recliner and coughed. I lost 7 pounds in the first 2 weeks – maybe it was all that exercise coughing! I don’t go to the doctor unless I think it’s the only way to avoid going to the hospital.

  16. Pam Forrester

    That all makes perfect sense. Thank you! I was doing Body by Science also but sustained a knee injury, perhaps by doing leg presses with too much weight at 66. It’s healing on its own by stopping but I also stopped all the other weight training. Now I am afraid I may be too old for it and will just do body weight. I think I will do Mark Sissons body weight exercises plus walking. I have been LCHF for 7 years and went keto again for Lent. Keto sends my Cholesterol sky high(300+) which does not concern me except when the doctor freaks out.

  17. Firebird7478

    I am one who has accumulated a lot of bodyfat since going low carb. I did better on The Zone Diet, but knowing what we now know, that diet is not practical in its application in relation to fat, grains, fruits, etc.

    I also attribute the added bodyfat to the fact that years ago they started talking about cardio being useless for fat loss. As a result, I have put away my roller blades. My knee is no longer conducive to sprints. And while I lift heavy weights 4X a week, in general, I have become rather inactive.

      1. Firebird7478

        My knee can handle long walks, just not sprinting or jogging. I was also warned off the treadmill by a podiatrist back around 2004. He had seen too much damage to the ligaments and tendons from the pounding the feet take. He told me if I wanted to walk, go outside. It’s harder to do because you are using your body’s natural stride (another reason he disliked the treadmill) plus, it is free.

        1. Tom Naughton Post author

          I’m pretty sure my feet aren’t taking a pounding by walking on the treadmill. It has something like shock absorbers built-in, and I see it rise and fall a bit as a I walk. But I’ve seen people at gyms running hard on those things and wonder what it’s doing to their knees.

    1. Emily

      Are you able to swim? Swimming is as close to no-impact as it gets, and it’s a full-body aerobic workout. There are generally water aerobics groups specifically geared for people with injuries at the local Y, too.

  18. The Older Brother

    Seems like you’ve somewhat inadvertently adopted the MAF program. It’s not the fact that you’re exercising, it’s that you’re exercising (as you said in one of the comments) at or below your Maximum Aerobic Function number , i.e., 180 – your age. That’s Phil Maffetone’s formula for the rate at which you are burning mainly fat, and over which you fairly rapidly switch back to being a sugar burner.

    I’m guessing that if you’re doing hour or sessions at a pace that you can still read, you’re probably around the sweet spot (119 BPM until November!). Have you checked with a heart rate monitor?

    I though the part of Sisson’s Primal Endurance that deals with this is actually better written that Maffetone’s books, but the important thing is that exceeding that rate will pretty much STOP your fat burning. Once you start burning sugar, you’re setting yourself up, as that is going to trigger your appetite to replenish said sugar/glucose stores.

    So, for those of us dealing with excess weight, exercising below the threshold = weight loss, but coming with a “no pain, no gain,” “more is better” attitude that almost every guru and gym jock pushes can mean a total stall.

    For people who were already regular cardio types (runners, cyclists. etc), the move down to the MAF level reported feeling like they were crawling for the few months it takes to get fat adapted.


    1. Tom Naughton Post author

      If the heart monitor on the treadmill is accurate (which is questionable, since you grip it with your hands), I’m right around that zone.

    2. Walter

      But isn’t it sugar we want to burn?! If we get rid of the sugar, then we will burn fat after the exercise.

      1. Mark

        The body’s storage sites for glucose are limited to muscle and liver tissue. On a LCHF diet, your body should only have as much glucose as needed for emergency fight-or-flight situations and should naturally be in fat-burning mode. The point of exercise should be to increase the fat-burning but not to where glucose stores are affected. As the Older Brother stated, burning this glucose will cause the body to work towards replacing it thus increasing appetite.

  19. Bob

    Excellent post and commentary. Thanks.

    I think it’s really what BobM (April 10 at 7:51AM) alluded to: the physiology is just too complicated. Naturally, we want to make it all simple and understandable. That doesn’t always work, and it’s especially bad when the “authorities” adopt an oversimplified one-size-fits-all position.

    Over the years I’ve read about LC nutrition, I have seen different attitudes about exercise and weight loss. Some seem to think the exercise works by impacting insulin and thus some level of metabolic syndrome. Others think “burning calories” is what matters. After all, there are SAD eaters who lose weight with exercise (I know one who did).

    I don’t think anyone really knows the answer. It seems to me diet is necessary but not necessarily sufficient for a lot of people. And exercise may be sufficient for some people. That’s why it’s so confusing.

    1. Tom Naughton Post author

      Agreed. Studies report average results, but people aren’t averages. Ultimately it comes down to what works for an individual.

  20. Firebird7478

    I’m a “gym jock” and I preach none of that and in fact, IDK any who does anymore. That is left for the roided up competitive bodybuilders but the rest of us believe in intense workouts, kept brief and allowing for the body to recover.

    1. The Older Brother

      No offense intended.

      The brief, intense workouts are an important part of overall health.

      What Maffetone stresses (and Sisson concurs with in PE) is that most people already have the strength needed to embark on a program geared towards becoming a “fat burner” instead of sugar. By feeling compelled to work in those intense workouts, however, the unadapted athlete will essentially sabotage their program.

      Maffetone suggests avoiding exceeding the MAF heart rate (180 minus your age, with some adjustments — see his website) for at least three months. That means no “lifting heavy things” for a few months while focusing on getting the metabolism retooled. He’s rehabilitated world class Iron Man and other athletes, who seem to unanimously chafe at the crawling pace initially, but after sticking with the program go on to personal best performances.


  21. chris c

    I think it’s true that “you can’t outrun a bad diet” but perhaps the corollary is “you CAN outrun a good diet”.

    I’m one of those weird people who seldom gains weight (it requires a dietician) but I can have all the other metabolic failures of a fat person. I also find a reverse correlation, in my high carb days I could walk for hours as long as I carried and ate/drank carbs every few hours (reactive hypoglycemia) and I would easily get hungry, well more probably carb cravings.

    Reducing fat even further as per dietician’s instruction made me semipermanently exhausted and constantly hungry, which is undoubtedly what led to the weight gain.

    Now on LCHF/paleo/keto I am back to walking for hours without the need to carry anything, and I often don’t get extra hunger until the following day, which makes evolutionary sense if my body sees exercise as hunting and gathering and not-exercise as a full larder.

    1. Tom Naughton Post author

      I agree with the corollary. Seems to work for me.

      I remember the days when I’d eat cereal for breakfast, then really NEEDED to each lunch. Now it’s eggs and meat for breakfast, and if I’m working outside or otherwise distracted, it doesn’t even occur to me eat lunch.

  22. Drifter

    Part of the problem with the “activity-isn’t-important-for-fat-loss” crowd is that it is important for lots of other health reasons. SO even if one can achieve a decent body composition primarily through diet, that doesn’t mean that that diet will support a healthy level and type of activity. I think that is why the people should follow the lead of the Ketogains/Ben Greenfield types rather than the diet-only crowd. I follow Ketotalk and similar podcasts and although I’ve learned a great deal, the complete absence of any discussion of activity levels invalidates a lot of the content IMO, which is very unfortunate since a lot of the info would be much more valuable in the context of quality activity levels.

    1. Tom Naughton Post author

      Agreed. I exercised even when I believed it wasn’t doing much for weight loss. I wanted the health benefits.

  23. 3Duranium

    Besides individual metabolism, there is also factoring the types of exercises done. I have found from years of experience that walks, jogs, planks, and even just moving around in high heat areas does much for losing fat. Other exercises such as push-ups, sit-ups, scrunches, etc. are great for muscle building but not for fat loss.

  24. Al

    Tom, have you considered the simple possibility that without the exercise there is just less opportunity for fat to be consumed? Where does fat go when we consume it? Sweat, urine, poop? No. Breath. It breaks down to carbon dioxide and you essentially breathe it out. If you’re doing no exercise you’re never out of breath and you’re limiting the number of breaths you need to take in any given day. Up the activity and you’re providing opportunity for the expulsion of much more CO2. That’s why they measure fat burning through CO2 concentrations in breath. But I’m starting to wonder… is there a limit to how much can concentrate in sedentary breath? Do we, perhaps, need increased heart-rate and breathing tempo to expel it all out? In any event, glad you’re better post-surgery. In the same way that you can’t be expelling it if you’re not consuming it (diet matters) you can’t be expelling it if you’re not giving it somewhere to go (exercise does count to give effect to the diet).

    1. Tom Naughton Post author

      Interesting thought. I have no idea how much fat is expended through breathing. Perhaps as an experiment, I’ll call Chareva anonymously and do some heavy breathing on the phone to see if I lose any weight.

      1. Al

        Expended is probably the wrong choice of word. Expelled is closer to the idea I was trying to convey. If one looks at the chemical reaction of lipolysis, the waste by product of burning body fat is co2 which can only be breathed out. At rest, there is a limit to how much co2 one can breath out (though this is not constant and is impacted by diet). When jogging for several minutes you may breath four times as fast, which opens up a release mechanism for increased expulsion. This alone suggests the view that exercise is unnecessary for dropping pounds is incorrect or at the very least much more likely to result in a plateau once you hit a sedentary limit on energy consumption and co2 breath expulsion concentration. As many of us have intuited from varying intake and exercise, these relationshiops are far from linear and probably vary from person to person due to hormonal sensitivity, health, etc. but there is definitely a relationship and elevated heartrate is your fat burning friend, especially if you are eating appropriately (which in some instances might mean lowering fat as well as sugary carbs). One can’t outrun a bad diet but running may be necessary to speed a good diet if one has excess fat to shed.


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