MinnMan

This is something that has been touched on many times in T&N, though I don't see a particular thread on it.

Lots of folks have pointed out that exercise (or rather, exercise alone) doesn't lead to weight loss. More specific would be that if your data tracking (power meter, etc.) tells you that you are burning x calories/week, over the long term, you aren't going to lose x/3500 pounds week (where 1 lb. = 3500 calories, usually).

A lot of this is commonly ascribed to greater food intake - exercise makes you hungrier, or you give yourself license to eat more b/c you had a long ride, or you consume calories as fuel before and during your ride.

The interesting and relatively new dimension (last 10 years or so) is metabolic compensation. The idea is that if you tire yourself out with a ride, you do less during the day. E.g., from calories you burn Saturday morning, you must subtract the calories you aren't burning Saturday afternoon because you're sitting on the couch, rather than doing household chores. Or because of your pre-work workout, you are tired and therefore are fidgeting less in your chair at work. From my understanding, some metabolic compensation isn't even voluntary - i.e., it's an evolutionary mechanism to conserve energy that kicks in, regardless of your level of non-workout activity.

There have been some good articles on this.

Here's one in the NYT (behind a paywall). https://www.nytimes.com/2021/09/22/w...-calories.html
Another, from Vox. https://www.vox.com/2018/1/3/1684543...-burn-calories

For me, the take home message isn't that you can't lose weight from exercise. From my own experience, I know that I can. Rather, it is that exercise is a rather limited weight loss tool, with net results likely to be smaller than one might hope.

WaveyGravey

Thanks for this info. For me an interesting and confusing subject. When warm weather arrives and I am able to ride 100 miles a week, weight rolls off of me. My clothing becomes loose and baggy. Sometimes I get too thin.

ScottCommutes

Thanks for this. I read Vox. The real value of bike riding as exercise for weight loss is the ability to move yourself up from a one slice of pizza workout to a whole pizza workout.

MoAlpha

Yeah, Herman Pontzer, who authored the first cited study, and is an anthropologist, not a nutrition or exercise guy, has lots of striking data from hunter-gatherers supporting this idea. However, there is a gap between the those findings and the smaller adaptations people see in prospective exercise studies. I heard him interviewed by someone smart and there is a strong critique of his studies, which he addressed very straightforwardly. Anyway, something important and interesting is going on there.

MinnMan

I'm no expert on the matter, but something that happens to me during the winter is that I end up exercising on the trainer at the very end of the day, maybe an hour starting at 10:30 PM or something like that. Then I'm up for a while (shower, read, etc.) and to sleep. This may be a mechanism to reduce metabolic compensation, as the resting comes at essentially the same time it would otherwise and then I start fresh the next day. On the other hand, I don't think we understand metabolic compensation enough to say that it really works that way. It could be that the metabolism (and, I guess, body temperature) is suppressed over longer periods of time.

pdlamb

I think there might be an analogy here to the famous saying (was it Eisenhower?), "Plans are nothing; planning is everything."

Exercise is nothing; it doesn't lead to weight loss. (Except possibly if you're really overweight and on a long, sustained exercise program, like hiking the Appalachian Trail or a trans-continental bike ride.) But exercise is everything; it makes weight loss possible. For a sedentary person who's trying to lose weight by restricting caloric intake, getting out of the chair and starting to exercise can jump-start weight loss like nothing else.

In between morbidly obese and underweight, it's frustratingly non-linear.

Carbonfiberboy 

I definitely notice this. I have to put in a lot of miles to make much of a difference. 300 TSS/week doesn't do anything other than improve my performance. At 700, I lose weight if I want to.

RChung

Nancy Howell, an anthropologist who wrote the definitive study on the nutritional strategies and energy expenditures of the Dobe !Kung of the Kalahari Desert, noted that teen males had high energy expenditures when hunting and compensated by lazing about when not hunting. The !Kung called teen males "owners of the shade."

terrymorse 

Above 700 TSS, I lose weight. Above 1000, I get up in the middle of the night to eat some more.

It seems that the "rest to see gains" concept is an old one.

Carbonfiberboy 

pdlamb

At 1000 TSS, I'd think the rest of 24 hours, between getting off the bike one day and back on the next, would comprise "the middle of the night" for me!

PromptCritical 

For us noobs, what is "TSS"?

MoAlpha

Training Stress Score. It represents the theoretical exercise stress of a ride and is a function of intensity (expressed relative to FTP) and duration. Sixty min. at FTP is arbitrarily assigned a TSS of 100, if I remember correctly. Looks like Terry means total TSS per week.

terrymorse 

Yes, per week. I should have made that clearer. 1000 TSS in a week is a big week—at least it is for me.

zandoval 

Muscle Weighs More Than Fat...

PromptCritical 

Thanks

RChung

It's a little more arcane than that but that's essentially it. So if 100 represents an hour at FTP, a weekly TSS score of 500 is supposed to represent 5 hours of riding at FTP. Terry occasionally does weeks of 1000 TSS, which approximates 10 hours at FTP: it may take him more than 10 hours to do that (or, rarely I hope, sometimes less than 10 hours) but that's a rough way to summarize both duration and intensity of a week's worth of rides.

The TSS model isn't perfect but for broad strokes it's not terrible, and I'd say it's often better than just tracking distance per week or time per week alone.

MinnMan

I admit that I haven't paid much attention to TSS in the past. I think maybe Strava calculates it if you are a subscriber? But I don't subscribe, so it doesn't calculate or display it. However, there is an external web calculator that I found that will peer into your Strava data and calculate your TSS scores

Strava TSS Calculator

I know nothing else about this site, and so caveat emptor.

Apparently, my normal training load at the moment is about 700/week. I can't say that I"ve lost much weight recently, though.

RB1-luvr

At 60 years old, I have never lost weight from riding. Riding makes me inordinately hungry. A 20-mile ride has me eating everything that's not bolted down when I get back. Jogging for some reason does not do the same. I do not feel like eating after I jog.

RChung

How many total hours on the bike do you do in a week to get about 700 TSS?
How many kcals (or kJ) is Strava saying you average across a week?

MinnMan

Though this includes the first week in April, when I was traveling over the weekend and only had 6.5 hours in the saddle.
Strava doesn't tally my kcal/week, though I suppose I could add it up pretty easily.

Edit: TSS for these 4 weeks, in reverse chronological order, 745, 699, 780, 349

RChung

Thanks. So, if you rack up 745 TSS in 11h of riding, it would mean you were averaging 745/11 = 68 TSS per hour of riding time. The way TSS is calculated means that your average "intensity" during that week's hours was about 0.82, which I think(*) is probably something like mid-Zone 3ish (on the 7 zone scale) for people who use zones.

(*) I don't use zones so I might be off on this, and it depends, of course, on how well you've estimated either FTP or CP.

MinnMan

Interesting.

It's possible that I don't have my FTP set right. It could be a little low, but not be more than 15 watts, I don't think.

terrymorse 

Yes, but not by much at all.

Jughed

I'm a gainer. I can pack on pounds over a weekend...

The only way I lose weight is a combo of exercise and a fairly extreme diet - 18 hour daily fasts, very low carb, whole foods, only water - and I may lose some weight.

I tried to get below and maintain a weight below 180#'s this winter - 200+ miles per week and ultra clean eating habits. I cut out everything and anything that could be considered excess. I got below 180 for a few weeks and felt like absolute poo in the process.

Any form of "properly fueling for a ride or efforts" = zero weight loss or even weight gain for me. If I fuel properly all the time - I will gain weight. And not just a few pounds of water.