Exercise Intensity Does Not Affect Depression of Resting Metabolic Rate during Severe Diet Restriction in Male Sprague-Dawley Rats

1993 ◽  
Vol 123 (7) ◽  
pp. 1270-1276 ◽  
Author(s):  
Douglas L. Ballor ◽  
Eric T. Poehlman
Keyword(s):  
Metabolic Rate ◽  
Exercise Intensity ◽  
Resting Metabolic Rate ◽  
Sprague Dawley ◽  
Diet Restriction ◽  
Sprague Dawley Rats

Effect of dietary restriction and/or exercise on 23-h metabolic rate and body composition in female rats

1991 ◽  
Vol 71 (3) ◽  
pp. 801-806 ◽  
Author(s):  
D. L. Ballor
Keyword(s):  
Weight Loss ◽  
Body Composition ◽  
Dietary Intake ◽  
Metabolic Rate ◽  
Resting Metabolic Rate ◽  
Normal Weight ◽  
Female Rats ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Heart Mass

This study examined the effects of three levels of dietary intake [ad libitum fed (AL), moderately severe (MSR), and severe restriction (SR)] and two levels of exercise [cage confinement (CC) and exercise training (E)] on 23-h resting metabolic rate (RMR) and body composition in 47 female Sprague-Dawley rats. At the end of the 9-wk study, the MSR and SR groups weighed approximately 81 and 61%, respectively, of the AL-CC group. RMR was depressed for the MSR and SR groups compared with the AL-CC group. This was true whether expressed on an absolute (ml/min) or relative (ml.min-1.kg-0.75) basis. On a relative basis, which accounts for changes caused by weight loss alone, the RMR decreased by approximately 12 and 19%, respectively, for the MSR and SR groups compared with the AL-CC group. Although E resulted in significant differences in fat mass, percent fat, percent water, and heart mass between the AL groups, there were no significant differences between E and CC groups at either the MSR or SR level of dietary intake for any of the variables measured (i.e., body composition, muscle mass, RMR). Thus E does not appear to affect the composition of lost weight or RMR during diet-induced weight loss for female rats of normal weight.

Exercise decreases fat selection in female rats during weight cycling

1991 ◽  
Vol 260 (3) ◽  
pp. R518-R524 ◽  
Author(s):  
T. Gerardo-Gettens ◽  
G. D. Miller ◽  
B. A. Horwitz ◽  
R. B. McDonald ◽  
K. D. Brownell ◽  
...  
Keyword(s):  
Dietary Fat ◽  
Food Restriction ◽  
Resting Metabolic Rate ◽  
Female Rats ◽  
Fat Intake ◽  
Weight Cycling ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Ad Libitum ◽  
Caloric Consumption

Weight cycling (weight loss and regain) increases fat intake in rats allowed to self-select a diet from protein, carbohydrate, and fat sources. This study reports the effects of exercise on macronutrient self-selection. Female Sprague-Dawley rats (5 mo old) self-selected their diet. After 3 wk, rats were assigned to one of the following three groups: ad libitum fed sedentary (Con), sedentary food restricted to 40% Con intake (R-Sed), or treadmill exercised (20 m/min, 1 h/day, 6 day/wk) food restricted to 40% Con intake (R-Ex). Food restriction was for 3 wk followed by 5 wk of refeeding. This was repeated for a second cycle. During restriction, body weight decreased by 30% in R-Sed and by 33% in R-Ex than in R-Sed, fat regain was greater in R-Sed. By week 3 of refeeding, total caloric consumption did not differ. However, fat selection increased in R-Sed (56% kcal) vs. R-Ex (30%) and Con (35%). Fat selection in R-Sed increased further during cycle 2 (73% kcal). Resting oxygen consumption decreased during food restriction in R-Sed and R-Ex. After refeeding, resting metabolic rate in R-Ex was significantly greater than in R-Sed. In conclusion, weight cycling increases dietary fat selection and adiposity. Exercise mitigates this effect.

Exercise-induced elevation of HSP70 is intensity dependent

2002 ◽  
Vol 93 (2) ◽  
pp. 561-568 ◽  
Author(s):  
Kevin J. Milne ◽  
Earl G. Noble
Keyword(s):  
Exercise Intensity ◽  
Striated Muscle ◽  
Exercise Bout ◽  
Treadmill Running ◽  
Hsp70 Expression ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Muscle Loading ◽  
Recruitment Patterns ◽  
Exercise Induced

Exercise induces expression of the protective heat shock protein, HSP70, in striated muscle. To characterize the relationship between induction of this protein and exercise intensity in muscles exhibiting different recruitment patterns, male Sprague-Dawley rats were assigned to a sedentary control or one of seven exercise groups for which treadmill running speed varied between 15 and 33 m/min ( n = 8/group). Twenty-four hours after a single 60-min exercise bout, hearts, red and white portions of the vastus (RV and WV, respectively) muscles, and soleus (Sol) muscles were harvested and analyzed for both relative and absolute HSP70 content. Cardiac HSP70 was significantly elevated only when animals were exercised at 24 m/min and beyond. Similarly, HSP70 was elevated in RV at running speeds above 24 m/min but did not increase in WV until 27 m/min. In contrast, HSP70 content was initially elevated in the Sol but subsequently declined at the highest running speeds. The observed patterns of HSP70 expression in skeletal muscle were in general accordance with known muscle recruitment patterns and suggest that alterations in muscle loading, resulting from changes in exercise intensity, are an important component of exercise-induced increases in HSP70 content.

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