Exercise during intermittent cold exposure prevents acclimation to cold rats.

Abstract

SUMMARY1. Energy balance and brown adipose tissue growth were examined in four groups of male Wistar rats: (i) sedentary, living at 24°C (warm), (ii) exercise-trained, 2 h daily, living at 24°C, (iii) living at 24°C but exposed to -5°C, 2 h daily and (iv) living at 24°C but exercise-trained while being exposed to -5°C, 2 h daily.2. Cold exposure during exercise training appeared to have little additional influence on body composition following 28 days of treatment; body mass gain, in addition to protein and fat gains, of exercised cold-exposed rats were similar to the gains observed in exercised warm-exposed control animals. However, in sedentary cold-exposed rats protein, fat and body mass gains were significantly lower than the gains measured in sedentary rats not exposed to cold.3. Metabolizable energy intake, expressed mass-independently, was similar in sedentary warm-exposed rats and both groups of animals that were exercise-trained. Metabolizable energy intake was increased almost 15% in sedentary cold-exposed rats.4. Energy expenditure (mass independent), excluding the net cost of exercise training, was not different in sedentary warm-exposed and exercised rats; energy expenditure was almost 20% higher in sedentary cold-exposed rats.5. Total protein and deoxyribonucleic acid (DNA) contents of brown adipose tissue were more than doubled in sedentary rats exposed to cold; protein and DNA levels were similar among the other three groups of rats.6. Treadmill running during daily, 2 h exposure at -5°C appears to prevent the cold acclimation responses that occur in sedentary rats receiving similar cold exposure.

Effects of exercise and intermittent cold exposure on shivering and nonshivering thermogenesis in rats.

“…These findings observed in intermittently cold-acclimated rats have been partially reported by other investigators (LEBLANC 1967;LEBLANC et al, 1967;BARNARD and SKALA, 1970;ARNOLD and RICHARD, 1987) and are among the common adaptations detected in chronically cold-acclimated animals (ALEXANDER, 1979). However, food intake of intermittently CA in the present study was not augmented (Table 1) as observed in other studies (HARRI et al, 1984;ARNOLD and RICHARD, 1987). In chronically cold-exposed animals energy intake is generally increased compensatory to increased energy expenditure (HARRI et al, 1984;RICHARD et al, 1986).…”

“…These observations indicate that our moderate-intensity exercise training program performed with daily, short-term cold exposure did not modify any of the adaptations that were observed to occur in our sedentary, intermittently cold-acclimated rats. Exercise (running) performed simultaneously with intermittent cold exposure has been previously shown to suppress cold acclimation (ARNOLD and RICHARD, 1987). However, in CA-T, T~ decrease measured at -20°C was greater than that in CA-S (Fig.…”

“…BAT is thought to be the dominant site of NST in coldacclimated rats (FOSTER andFRYDMAN, 1978, 1979). In addition, exercise training performed concomitantly with intermittent cold exposure was observed to prevent the increased growth of BAT and the change in energy balance that occurred in sedentary, intermittently cold-exposed rats (ARNOLD and RICHARD, 1987). In other words, exercise performed during intermittent cold exposure appeared to eliminate the cold acclimation observed to occur in sedentary cold-exposed rats.…”

“…In other words, exercise performed during intermittent cold exposure appeared to eliminate the cold acclimation observed to occur in sedentary cold-exposed rats. The results of Arnold and Richard (1987) also suggest that if exercise-induced improvement in cold tolerance occurs (CHIN et al, 1973;OSTMAN-SMITH, 1979;ASTRUP, 1986), it would not seem to be directly related to BAT thermogenic capacity. However, the mechanism and tissues involved in the interaction between exercise training and cold acclimation (including improved cold tolerance) remain unidentified.…”

Effect of Repeated Cold Water Swimming Exercise on Adaptive Changes in Body Weight in Older Rats

“…However, the body weight of Apodemus sylvaticus and Acomys cahirinus was not affected by cold acclimation (Klaus, Heldmaier, Ricquier, 1988;Khokhlova, Krasnov, Shenbrot, Degen, 2000;Gunduz, 2002); on the contrary, the body weight of Phodopussungorus, Microtusochrogaster, M. pennslvanicus and Clethrionomysglareolus decreased during cold acclimation (Klaus et al, 1988;Wiesinger, Heldmaier, Buchberger, 1989;Voltura, Wunder, 1998;Wang, Wang, 1990). In the study by Arnold, Richard (1987), cold exposure had no additional effect on body composition in physically active rats. Compared to rats trained at 24°C, exercised cold-exposed animals did not utilise more of their fat or protein stores in providing substrate for exercise.…”