Too much cardio, not enough calories, magic metabolism and physics

[Steve]

I discuss Lyle McDonald's stuff a lot around here. More so as of late simply b/c he's been putting out some very interesting stuff on his forum, on his blog, and in his newsletter. If anyone is interested in reading some technical stuff from a brilliant exercise physiologist and nutrition master, check out .

I'm sure many aren't going to go signing up though so I try and bring the relevant stuff to this forum as much as possible. There's a very interesting thread going on over on his forum right now regarding the times where our bodies seem to go against what basic physics and thermodynamics tell us about calories in vs. out.

The fact is that fat loss will always be about calories out vs. in. The basic laws of physics aren't going to change... at least not in our lifetime. That said though, there definitely seems to be things that mask fat loss and at times halt it. Women who don't have a lot of weight certainly experience this. I've experienced this at certain points in my 'training career.' Lyle can't explain it so I sure as shit can't explain it. I call it magic. At least until someone comes up with better explanations. I believe Lyle might be working on a project regarding this fascinating subject... but he hasn't really come out and said that yet. I'll probably ask him more about it when I interview him.

That said, I wanted to bring some of the interesting stuff from that thread over hear for anyone interested....

 

[Steve]

forum member:

While we're making fun of "ur metabolizm will shut dawn" and other bro science...
What up with the metabolism shutting down with excessive cardio and a large deficit?! Even Lyle said this.

It's gotta be true.

[I think it's one of his future projects to work on that issue.]

Lyle

some weird shit happens, that's all I can say about it right now

forum member

How weird? Like a John Water's movie weird?

Lyle

nah, more of a 'the math doesn't add up' kind of weird

like some ends of physics

Lyle again

and to clarify what I have said about this a little bit more clearly, what some resaerch suggests is that excessive activity + a large caloric deficit can cause an otherwise greater reduction in metabolic rate than you'd otherwise see

this will never be sufficient to eliminate the deficit, but it may lower the net deficit compared to what you'd get with a more moderate approach

as well, there appears to be some goofy shit going on with water balance that tends to mask true fat loss.

Lyle again

This is one of the only studies I've seen on it, they 6 hours/week of fairly low intensity cardio to what is essentially a protein sparing modified fast. it's a lot of why I suggested what I suggested in teh rapid fat loss book

but I have seem some odd things happen at even higher calorie levels, usually with excessive cardio (in my own personal case, 2 hours/day). weight/fat loss seems to stall completely. I kept cutting calories harder and it just made things worse, at least acutely. of course, some of this is colored by the fact that, during this time, my 'refeeds' were becoming progressively worse in terms of too much dietary fat. it may simply have been that I was replacing any fat lost during the week with shitty weekeends

but I have seen smilar things in others

I also have a feeling that certain bodies are relatively more or less sensitive to such things, the system is just more 'resilient' for whatever reason.

I also suspect that water balance issues are a lot of what's going on

***
Metabolism. 1988 Aug;37(8):758-65.Click here to read Links
Effects of aerobic exercise on energy expenditure and nitrogen balance during very low calorie dieting.
Phinney SD, LaGrange BM, O'Connell M, Danforth E Jr.

General Clinical Research Center and Metabolic Unit, University of Vermont College of Medicine, Burlington.

Aerobic exercise in addition to severe caloric restriction was studied for its effects on resting energy expenditure (REE), weight loss, and lean tissue preservation in adult women. A formula diet providing 1.5 g protein and 0.5 g carbohydrate (CHO) per kilogram of ideal body weight daily (mean intake 720 kcal/d) was given to 12 overweight inpatients for 4 to 5 weeks. Six subjects remained sedentary (group 1), while the other six subjects (group 2) performed supervised endurance exercise (a total of 27 hours at 50% of maximal oxygen uptake (VO2max) over 4 weeks). Lean tissue preservation was excellent in both groups and was unaffected by the group 2 exercise regimen. Weight loss over 4 weeks in the two groups did not differ (group 1, 6.9 +/- 0.7 kg; group 2, 6.5 +/- 0.7 kg). The VO2max was not increased after 4 weeks of exercise compared with controls. The resting oxygen consumption (rVO2) of both groups declined 10% (P less than .001) in the first seven days of dieting. Thereafter the rVO2 in group 1 remained stable, but a further 17% reduction occurred in group 2 (P less than .03) by the third week of exercise. The free triiodothyronine (fT3) concentration also fell more in group 2 (P less than .05), suggesting a relationship between fT3 and energy expenditure during severe caloric restriction. The ergometer exercise for up to two hours daily was well tolerated. The absence of either a training effect or accelerated weight loss in group 2 may be due to the limited duration (4 weeks) or intensity of the exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

 

[Steve]

forum member

Thius is probably gonna sound weird but in my experience look at your appetite. I think you are more than likely to notice this if your appetite reduces in conjunction with your deficit. It's almost like your system adapts to function at a lower level. Thus you might only be eating 1200 calories per day, but you won't be starving either. If you're starving that's not necessarily a bad thing.

Lyle

in a related way, I rmemeber taking a VERY informal poll of folks back in the mfw days. most reported that optimal fat loss occurred when they reported slight (but not mssive) hunger. presumably indicative of a slight but not excessive deficit

 

[Bigguy]

Isn't this very close to what is usually stated here?
Excessive calories + Manic cardio does not always equal huge fat loss..
I thought that was a principle of weight/fat loss.
I do not understand the phenomena but then again I do not have to understand it to abide by it.

 

[Steve]

No, we promote 'sane' deficits for certain reasons but not b/c of some magical issue going on metabolically. We know of the various adaptations associated with dieting, starvation or not... but this goes beyond that.

 

[Bigguy]

No, we promote 'sane' deficits for certain reasons but not b/c of some magical issue going on metabolically. We know of the various adaptations associated with dieting, starvation or not... but this goes beyond that.

Gotcha.
This is all beyond my grasp of the mechanics behind the scene anyway.
But I just wanted to see if this was new information of the same presented differently.