Random Thoughts: Obesity, Weight loss, Metabolism, Diet & Exercise
In the interests of saving a bit of time and gathering thoughts, I thought I'd jot down some would-be comment replies in a blog post instead. First, so we're all (newer readers especially) on the same page, I did no formal exercise during the active weight loss phase and long plateau from sometime summer 2007 through spring 2009. This was not really by design, but more out of fear as the last time I low carbed I experienced the racing heart mostly when doing rather short periods of pilates and such. So I kept meaning to up the activity level a bit but never really managed to get around to it. In 2009 I did start doing concerted cardio -- walking and biking -- and later some more cardio-like exercise DVD's. As for strength training, the only formal training I have done was that 100 pushups thing that was popular in 2010. I got to 100 "girlie" pushups and was on my way with the regular ones when I pulled something in my side that made rolling over in bed painful! So for me personally, regular exercise is a sporadic thing at best ... something I am trying to dedicate myself to just never seems to stick. That said, I am very active. Initially this was just doing the "parking far away at work" thing and such, but has progressed to deliberate short bouts of exercise like walking around the yard when I bring the garbage out, always running up stairs, just going up and down stairs for the heck of it, etc.etc. Additionally, we go through a lot of wood with our fireplace to heat part of our home and I do pretty regular "workouts" transporting/stacking, chainsawing, etc. wood.
Should the Obese Exercise?
My 2007 before picture is of me catching my breath after planting peas. In those days, walking even normal distances had me with swollen painful ankles by noontime. So when I discuss exercise here and by all means encourage it, it is with several qualifications/reservations. Depending on one's level of obesity and accompanying fitness, exercise may be counterproductive. If you're enough overweight that it impacts your ability to walk/move and your endurance is poor, obviously starting an ambitious walking program is not a good idea. I must say that I've been surprised there aren't more injuries and health-scare events on shows like The Biggest Loser. It's really just not a great idea for very overweight people to move a whole lot more in weight bearing/impact movements.
What's the Best Exercise for Obese?
Answer: Whatever activity gets you moving more with smallest risk of injury. The end goal is to be an active slimmer person. When still obese, some light cardio may be best to get that "moving more" going. Aqua-aerobics or stationary cycling may be good places to start. If you're reasonably active, significantly obese, resistance training is likely not that big a deal for weight loss. Yes, it can impact insulin sensitivity, but IR is not what's making/keeping you fat and will likely resolve as weight drops. A crash diet seems to be more effective in resolving "critical mass" metabolic issues than exercise. So initially the goal should be habit-building for moving more if anything. As weight loss progresses, the goal should be to increase activity. As stated earlier, I did practice what I preached here, just not in the form of regimented "exercise". Also as weight drops, preservation of lean mass becomes more critical. Unless you were a total couch potato, when you got obese you've also gained lean mass -- especially on the rebound off LC if "drifting" off LC means just eating more "bad carbs" while still eating all those meaty treaties ... Think that recent Bray overfeeding study. Some of that lean mass is organs and bones, not just skeletal muscle, and will/should be reduced along with fat mass. As you get closer to goal/normal, this is probably the better time to address a resistance program. I suppose if you're total couch potato -- especially a long standing older obese -- it's never too early in the intervention to focus on lean mass retention and building -- but in the beginning it's really probably not that critical.
I'm all about functional strength. So think about it, you are already strong where it counts if you can climb stairs with 100 extra pounds on your bod. Now after significant losses -- perhaps 30 or so pounds -- it may be time to actively "train" those muscles to maintain the strength. After all, you're now only "lifting" 70 extra pounds. Personally I'm not a fan of the 15 minutes a week vein of resistance training. If you're a weakling unable to lift a 10 lb bag of cat litter onto the belt and carry it to your car, perhaps this is for you as you are strength deprived. But if you're talking building actual muscle mass and such, it's not going to cut it.
At about the 50% to goal point I think is likely the best time on average to ramp up some cardio and/or add some high intensity interval training. Still, "sprints" are really not a great idea for the obese, and let's face it, many are still obese at 50% to goal. If you're going to do it, choose non-weight bearing or add incline/weighted vest to a walking regime. That's my best rec to fat folks. Too many never fat folks selling potentially dangerous routines on folks still too large to do them. I had a rude awakening a couple of years ago when I had visions of doing a 20 year anniversary repeat of a sprint triathlon. No can do on the running peeps. My joints do not know nor care what the composition or size/shape of my bodyweight takes (and I'm an outlier there). They just know it's too much to be pounding pavement with.
Is Exercise Essential?
It seems that exercise may not be essential to lose weight, but to maintain and achieve optimal results? That's a whole 'nother story. I'm sure that formal exercise can only improve my own outlook moving forward, and I'm a difficult case in that I'm quite sure a lot of my "moving more" is quasi-exercise, just not rigidly or even haphazardly scheduled. Still, if you've lost enough weight to improve ambulatory capability and resolve some weight-bearing issues on joints and you're not moving more, this is not generally a good sign for maintenance. Can it be done? Sure. But chances are you'll at least have an easier time of it exercising in some way, shape or form.
What the study in my latest blog post revealed, is that sufficient protein + good ol' cardio exercise seems to kick in a way to gain muscle mass -- if not total lean mass which was not assessed. Since low carb tends to be higher protein by default vs. the standard 15% protein diet, there's opportunity here folks, for adding just a bit of exercise to retain lean mass. Studies are inconsistent with diet only. Just eating more protein in energy deficit does not seem to preserve lean mass any better than a standard diet so long as that standard diet contains sufficient protein in an absolute gram amount. But "use it" and protein is partitioned to lean mass accumulation while fat mass is catabolized further? Seems perhaps so.
On the metabolism front, and I'll have a more organized post on this topic, there's certainly a "metabolic advantage" to exercising/activity. As we age, weight cycle, etc. metabolic rate falls. Not always, not always to the same extent, but on average and with considerable predictability, it does. AND, energy needs will fall as body weight including lean mass falls. One must adapt intake or plateauing and/or regaining is inevitable. But let's look at two scenarios, again referring to the study from my previous post. Establish 2500 cal/day deficit by either diet or exercise, lose same amount of weight, likely close in percent total lean/fat (this wasn't quantified). But, keep that up over time and the exercisers will likely retain more lean mass and RMR and TDEE while the calorie restricters will likely lose LBM and go into some degree of compensatory reduction in RMR. End of the day the exerciser burns 2000 cal/day and stops exercising and gains weight as does the dieter. But the dieter now burns 1800 cal/day so likely gains faster and is more prone to binging after prolonged restriction. Nasty cycles, eh?
To be continued ....