Throughout the Northern Hemisphere, people who love to row are renewing their annual winter friendship with the rowing machine, known as the ergometer (ur-GAW-muh-tur) or more affectionately as just the erg. Distance erging (yes, it’s also a verb) is particularly inspired by a perverse celebration known as the Holiday Challenge, a fun- and fund-raiser sponsored by Concept 2, manufacturers of a popular erg. Rowers aspire to erg 100,000 or 200,000 meters between Thanksgiving and Christmas, competing as individuals and as teams to achieve that goal first. A decent sustainable pace is 10,000-12,500 meters per hour, so we’re talking about either 8-10 or 16-20 hours spent sliding back and forth (on an unforgiving seat I might add) pulling a chain off a resisting flywheel and following it “back up the slide” as it recoils. And then again: 22-28 times a minute, for 8-16 hours. As members of the rowing team, we are also spending time each week actually rowing on the water, as well as doing some interval workouts and, oh yes, our jobs and families.
As a member of the competitive voice of the Ashland Rowing Club, I’ve received a number of emails encouraging me to participate. While it’s easy to protest that I have neither the time nor the patience for the Holiday Challenge, there’s more to my decision than mere avoidance. We already have a top-notch training program, so I don’t think anyone believes the exertion will significantly improve anyone’s fitness levels. However, it is the common wisdom that the Challenge is a good excuse to enable holiday treat consumption, protect against weight gain, and maybe even shed a few pounds.
While we’re on the subject, did you know that half of the U.S. annual weight gain occurs over the holidays? And that most of that weight is retained indefinitely. I’m going to suggest to you, with the help of Gary Taubes’ article from a few years ago, that if you are someone with a weight problem, you, too, should avoid the Holiday Challenge, as it won’t help, and could hurt your struggles with the bulging waistline: that’s right, hours of spinning the erg’s flywheel could adversely impact the spin on your scale dial. (Remember when scales had dials?)
While there are actually many good reasons to be active (fitness, pleasure, reduced disease risk, increased self-esteem), weight loss isn’t one of them, if you rely on science for your information. Experts in cardiology and sports medicine agree that although it may be reasonable to suppose that more exercise should protect against weight gain, “so far, data to support this hypothesis are not particularly compelling.” That is to say, decades of research on exercise as crucial to weight loss can’t really validate its scientific worthiness.
In fact, the exercise explosion noted in 1977 by the New York Times as a rejection of the 1960’s notion that exercise was “bad for you” fairly well parallels our obesity explosion, wouldn’t you say? But how can that be, you ask – if you burn off more calories than you eat, won’t you lose weight?
Well, worse than ineffective, exercising to lose weight is a plan that may actually backfire and cause weight gain.
An alternate hypothesis to the prevailing “common sense” (that exercise makes you thin) would be that thin people are driven to exercise because a thin body is hormonally set against storing calories as fat. I could cite our rowing club’s two highest-meter ergers’ low body fat percentages as evidence, but I should be more scientific than that.
We have indeed learned over the last 30 years that our fat tissues are not simple repositories for excess calories consumed but rather complex hormonally driven systems that also interact with our moods, our sleep, our activities, our intestinal flora, and our choice of foods. Our fat tissue does in fact store energy (calories), but it also can retain or release that stored fat, acting on hormone messaging regulated through its own internal little gatekeeper, lipoprotein lipase (LPL) for the physiologists among you.
During exercise LPL is active in muscle tissue, so our muscles can pick up fatty acids to use for fuel after muscle glycogen is depleted. After exercise, muscle LPL quiets down and fat tissue LPL activates: pulling calories circulating as blood glucose into cells, converting them into fat thereby returning to the fat cells what they yielded up for the benefit of our exercise. The lowered blood sugar makes us hungry: our brains particularly are habituated to burning sugar for fuel, and cry for more if our blood sugar goes down. Many studies have shown that exercise suppressed appetite for a few hours, but most acknowledge that eventually our desire for replenishment prevails and we have a good hearty meal after a good workout.
The blood sugar and LPL dance is orchestrated by the hormone insulin, which has a particularly cozy and suspicious arrangement with both dietary carbs – the more carbs eaten, the more insulin shows up for the party – and stored fat. Insulin turns out to be a hoarder: insulin directs LPL both to “Store more fat!” and to “Stop burning fat for fuel!” If we are overweight (particularly in our mid-sections), our cells have tired of insulin’s constant refrain, and ignore insulin, leaving more blood glucose in the bloodstream, which summons up even more excessive amounts of insulin. For a while at least, the extra insulin still works – it still shunts sugar out of the bloodstream, stores it as fat, and locks it up in fat storage. Until it stops working, and then you have diabetes.
One more detail to stress a bit before I wrap up my Holiday Challenge argument: the sweeter the food you’re eating, the more insulin your body makes, and the longer that insulin effect persists in your body, even up to a week or more, depending on your physiology. And remember that insulin’s main response to the sweets you eat is to hoard them as stored fat, and to keep that fat locked up, preventing its use for exercise, even 10,000 meters on the erg. So any significant sweets consumed before exercise will fuel that exercise, but compel your pre-existing fat tissue to stay put.
So the way I see it, the Holiday Challenge only stimulates LPL to lock away calories as fat. And any excuse I imagine it gives me for eating more sweets will only backfire in the end (in my end, that is), and that effect could persist seven to ten days beyond the consumption of those sweets. Happily, there are strategies for both eating and exercising that dissolve my fear of the holidays. How about you, what is your attitude toward seasonal feasting?