This study leaves no doubts that CRed mice that did not exercise were healthier than mice with normal diets that exercised regularly. What about CR + exercising? Would it bring significant added benefits to people already on a CR diet?
One More Study on CR; guess the results...
#1
Posted 15 May 2008 - 05:27 PM
This study leaves no doubts that CRed mice that did not exercise were healthier than mice with normal diets that exercised regularly. What about CR + exercising? Would it bring significant added benefits to people already on a CR diet?
#2
Posted 15 May 2008 - 06:32 PM
You could construct a diagram like this:
with the height of the curve at a specific point being the amount of benefit you get at that precise ratio between CR and exercise.
We know the starting point (only CR, no exercise) and the end point (no CR, only exercise), and we know that the starting point is higher on the benefit scale than the end point, but we don't know how the curve looks between those points. Perhaps it's like the green curve, with maximal benefits standing to be gained when only doing CR to a high degree, and not exercising. Or maybe it's like the red curve, with the maximum benefits coming with a bit less CR and a bit more exercise.
Are there any studies on this?
Edited by Johan, 15 May 2008 - 06:53 PM.
#3
Posted 15 May 2008 - 06:55 PM
edit: i like this graphic. Now we just need the info to make it be right =/
I don't think there are enough studies to give us an answer right now. But since these studies with mice aren't very expensive, someone could do them to find the ideal lifestyle, whether it's a combination of CR with exercise or just CR.
Edited by sam988, 15 May 2008 - 06:58 PM.
#4
Posted 15 May 2008 - 07:11 PM
Edited by Johan, 15 May 2008 - 07:13 PM.
#5
Posted 15 May 2008 - 08:15 PM
#6
Posted 15 May 2008 - 08:27 PM
#7
Posted 15 May 2008 - 08:40 PM
Anyway, at the most basic level, it seems CR works because you end up burning fewer calories and thus you have less damage accumulate throughout life.
#8
Posted 15 May 2008 - 08:44 PM
#9
Posted 15 May 2008 - 08:48 PM
#10
Posted 15 May 2008 - 08:51 PM
#11
Posted 15 May 2008 - 09:38 PM
From what I have read, CR also enhances some DNA repair pathways, so the damage that does occur gets fixed a lot better.Anyway, at the most basic level, it seems CR works because you end up burning fewer calories and thus you have less damage accumulate throughout life.
Anyway, I think the red curve in my diagram is a closer match to reality than the green one - mostly CR with light exercise (like daily activities - walking, biking, etc.). I imagine that a totally sedentary person would be worse off than a reasonably fit one, even if the former was doing CR to a greater extent than the latter - as long as the difference isn't too large. At some point, the benefits of exercise seem to become outweighed by the fact that you have to eat more to keep it up.
Edited by Johan, 15 May 2008 - 10:09 PM.
#12 Guest_Kismet_*
Posted 21 May 2008 - 04:02 PM
Wouldn't it be most optimal when on CR to just do daily activities for "exercise".If they are complete couch potatoes their health may detoriate but why should they exercise more than normal daily walking and activities like gardening etc....
You seem to be quite negative towards exercise *g*
I am new to life-extensionism, sorry if this has been discussed already...
Could someone explain the rationale why CR+exercise should be worse than CR alone?
CR aims to cut the calories of an ad libitum diet, let's say -30%. My understanding of ad lib is based solely on Wikipedia "at one's pleasure"~ eating as much as your body needs (to maintain weight?).
However, exercising you increase BMR and MR in general (burn more calories) thus the ad libitum diet of an exercising organism is naturally higher, but cutting it by -30% should still achieve the same or comparable results as cutting an ad lib diet of a non-exercising organsim, no? (BOTH diets are ad lib, but differ in calories)
OR did I get the definition of CR wrong? I can see that people try to use some kind of weight set-point but calorierestriction.org states "In fact, CR's anti-aging effects manifest themselves even in organisms with a 'healthy' weight", so is CR still defined as 'cutting ad libitum diet intake', if so, why is my approach ^ wrong?
It seems the FAQ on calorierestriction.org refutes my idea, but they give no rationale whatsoever:
"Please note: Increasing exercise, losing weight, and keeping Calories unchanged is not what CR is about. An exercise regimen that keeps you slim and leaves Calorie intake unchanged is not CR, but simply a health program for weight control to slim down."
#13 Guest_Kismet_*
Posted 25 May 2008 - 12:26 AM
John O. Holloszy. Mortality rate and longevity of food-restricted exercising male rats: a reevaluation. Journal of Applied Physiology Vol. 82, No. 2, pp. 399-403, February 1997 EXERCISE AND MUSCLE
http://jap.physiolog...e832a59843c#B16
At least they conclude that exercising is not harmful to CR:
“The present results show that exercise does not interfere with the extension of maximal life span induced by food restriction. The beneficial effects of food restriction and exercise on survival are not additive or synergistic in male rats.“
However, the study cannot answer the question whether restricting calorie intake through exercise is as effective as restricting food intake, because their test animals gained no benefit from >30% CR:
"It is therefore of interest that the 30% food-restricted runners in group C and the paired-weight sedentary rats in group D, which had to be food-restricted by ~50% to keep their body weights the same as the runners', had similar survival curves despite the difference in degree of restriction. Interpretation of this finding is complicated because, although food intake was different, the relative caloric deficit and the degree of growth retardation were similar in the food-restricted runners and the paired-weight sedentary rats. However, our previous study included both ~30% and ~50% food-restricted sedentary groups, and their survival times were also not statistically significantly different"
Regarding the question of CR and exercise being synergistic, I don't think one can draw conclusions, from a simple rat study, like "The beneficial effects of food restriction and exercise on survival are not additive or synergistic in male rats.“ - thus they won't be in humans.
We exercise in a more sophisticated way than wheel-running rats and the study merely included endurance type of training, whereas strength training could be much more beneficial for human CR practitioners (bone density, strength, etc).
#14
Posted 29 May 2008 - 06:40 PM
I have found an interesting study on that topic.
John O. Holloszy. Mortality rate and longevity of food-restricted exercising male rats: a reevaluation. Journal of Applied Physiology Vol. 82, No. 2, pp. 399-403, February 1997 EXERCISE AND MUSCLE
http://jap.physiolog...e832a59843c#B16
At least they conclude that exercising is not harmful to CR:
“The present results show that exercise does not interfere with the extension of maximal life span induced by food restriction. The beneficial effects of food restriction and exercise on survival are not additive or synergistic in male rats.“
However, the study cannot answer the question whether restricting calorie intake through exercise is as effective as restricting food intake, because their test animals gained no benefit from >30% CR:
"It is therefore of interest that the 30% food-restricted runners in group C and the paired-weight sedentary rats in group D, which had to be food-restricted by ~50% to keep their body weights the same as the runners', had similar survival curves despite the difference in degree of restriction. Interpretation of this finding is complicated because, although food intake was different, the relative caloric deficit and the degree of growth retardation were similar in the food-restricted runners and the paired-weight sedentary rats. However, our previous study included both ~30% and ~50% food-restricted sedentary groups, and their survival times were also not statistically significantly different"
Regarding the question of CR and exercise being synergistic, I don't think one can draw conclusions, from a simple rat study, like "The beneficial effects of food restriction and exercise on survival are not additive or synergistic in male rats.“ - thus they won't be in humans.
We exercise in a more sophisticated way than wheel-running rats and the study merely included endurance type of training, whereas strength training could be much more beneficial for human CR practitioners (bone density, strength, etc).
Yea this is really a delicate issue where we don't have definite answers yet. Partly because we don't even know vert well how and where in the body CR works and what triggers it; our science is still so primitive...
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