Exercise Intensity and the Thermic EfiWif of Food

1992 ◽  
Vol 2 (1) ◽  
pp. 87-95 ◽  
Author(s):  
Kent W. Goben ◽  
Gary A. Sforzo ◽  
Patricia A. Frye
Keyword(s):  
Exercise Intensity ◽  
High Intensity ◽  
Treadmill Exercise ◽  
Liquid Meal ◽  
Low Intensity ◽  
Thermic Effect Of Food ◽  
Effect Of Food ◽  
Low Intensity Exercise ◽  
Male Subjects ◽  
Thermic Effect

This study investigated the effect of varying exercise intensity on the thermic effect of food (TEF). Sixteen lean male subjects were matched forand randomly assigned to either a high or low intensity group for 30 min of treadmill exercise. Caloric expenditure was measured using indirect calorimetry at rest and at 30-min intervals OYer 3 hrs following each of three conditions: a 750-kcal liquid meal, high or low intensity exercise, and a 750-kcal liquid meal followed by high or low intensity exercise. Low intensity exercise enhanced the TEF during recovery at 60 and 90 min while high intensity enhanced it only at 180 min but depressed it at 30 min. Total metabolic expense for a 3-hr postmeal period was not differently affected by the two exercise intensities. Exercise following a meal had a synergistic effect on metabolism; however, this effect was delayed until 180 min postmeal when exercise intensity was high. The circulatory demands of high intensity exercise may have initially blunted the TEF, but ultimately the TEF measured over the 3-hr period was at least equal to that experienced following low intensity exercise.

Thermic and Glycemic Responses to Bread and Pasta Meals with and Without Prior Low-Intensity Exercise

2007 ◽  
Vol 17 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Penelope M. Warwick
Keyword(s):  
Blood Glucose ◽  
Energy Expenditure ◽  
Healthy Volunteers ◽  
Low Intensity ◽  
Prior Exercise ◽  
Thermic Effect Of Food ◽  
Effect Of Food ◽  
Low Intensity Exercise ◽  
Blood Glucose Concentrations ◽  
Thermic Effect

The purpose of the study was to investigate thermic and glycemic responses to conventional meals with and without prior low-intensity exercise. Fourteen healthy volunteers (7 men, 7 women) undertook 4 treatments, 2 bread and 2 pasta meals, either with (E) or without (NE) prior exercise (a 45-min treadmill walk). Meals provided 58 g carbohydrate and 2360 kJ. Energy expenditure and blood-glucose concentrations were measured before and for 3 h after the meals. The thermic effect of food (TEF) was lower after pasta (121 ± 32 kJ/3 h) than after bread (154 ± 62 kJ/3 h), P = 0.009, but was not affected by exercise. Glycemic responses were lower after E (155 ± 113 mmol·L−1 ·3 h−1) than NE (199 ± 97 mmol·L−1 · 3 h−1) after pasta (P = 0.020) but not after bread. TEF was lower after pasta than bread but was not affected by prior low-intensity exercise. The effects of exercise on glycemic responses to meals were inconsistent.

Reflex versus autoregulatory control of hindlimb blood flow during treadmill exercise in dogs

1991 ◽  
Vol 260 (2) ◽  
pp. H436-H444 ◽  
Author(s):  
L. G. Koch ◽  
D. M. Strick ◽  
S. L. Britton ◽  
P. J. Metting
Keyword(s):  
Blood Flow ◽  
Arterial Pressure ◽  
Exercise Intensity ◽  
Treadmill Exercise ◽  
External Iliac Artery ◽  
Flow Probe ◽  
Low Intensity ◽  
High Exercise Intensity ◽  
Neurohumoral Control ◽  
Low Intensity Exercise

To evaluate the competition between local autoregulation and reflex neurohumoral control of hindlimb blood flow (HLBF), the hindlimb vascular pressure-flow relationship was determined in nine dogs in response to a 10% decrease in mean arterial pressure (AP) imposed during both low (3.0 km/h, 0% grade) and high (5.5 km/h, 14% grade) intensities of treadmill exercise. HLBF was measured with a Doppler flow probe on the left external iliac artery, and AP was controlled with a gravity reservoir connected to the left carotid artery. A 10 +/- 2% reduction in AP for 25 min caused HLBF to decrease 25 +/- 2% during low-exercise intensity but only 10 +/- 2% during high-exercise intensity. The corresponding closed-loop gains (Gc) of HLBF regulation [Gc = 1 - (% delta hindlimb blood flow/% delta hindlimb perfusion pressure) were -1.6 +/- 0.4 and -0.06 +/- 0.2 during low- and high-exercise intensity, respectively. Autonomic ganglionic blockade (hexamethonium) increased the Gc during low-intensity exercise to 0.07 +/- 0.2. Antagonism of adenosine receptors (aminophylline) decreased the Gc of HLBF regulation during high-intensity exercise to -0.57 +/- 0.3. These data demonstrate that in response to an imposed decrease in AP, autonomic vasoconstriction overrides autoregulatory vasodilatory mechanisms during low-intensity exercise. HLBF regulation increases at a higher exercise intensity, in part due to adenosine, but autoregulation does not predominate over arterial pressure regulating mechanisms.

Phenylephrine decreases frontal lobe oxygenation at rest but not during moderately intense exercise

2010 ◽  
Vol 108 (6) ◽  
pp. 1472-1478 ◽  
Author(s):  
Patrice Brassard ◽  
Thomas Seifert ◽  
Mads Wissenberg ◽  
Peter M. Jensen ◽  
Christian K. Hansen ◽  
...  
Keyword(s):  
Frontal Lobe ◽  
High Intensity ◽  
Sympathetic Activity ◽  
Near Infrared ◽  
Cerebral Metabolism ◽  
High Intensity Exercise ◽  
Mean Flow ◽  
Intense Exercise ◽  
Low Intensity ◽  
Low Intensity Exercise

Whether sympathetic activity influences cerebral blood flow (CBF) and oxygenation remains controversial. The influence of sympathetic activity on CBF and oxygenation was evaluated by the effect of phenylephrine on middle cerebral artery (MCA) mean flow velocity ( Vmean) and the near-infrared spectroscopy-derived frontal lobe oxygenation (ScO2) at rest and during exercise. At rest, nine healthy male subjects received bolus injections of phenylephrine (0.1, 0.25, and 0.4 mg), and changes in mean arterial pressure (MAP), MCA Vmean, internal jugular venous O2 saturation (SjvO2), ScO2, and arterial Pco2 (PaCO2) were measured and the cerebral metabolic rate for O2 (CMRO2) was calculated. In randomized order, a bolus of saline or 0.3 mg of phenylephrine was then injected during semisupine cycling, eliciting a low (∼110 beats/min) or a high (∼150 beats/min) heart rate. At rest, MAP and MCA Vmean increased ∼20% ( P < 0.001) and ∼10% ( P < 0.001 for 0.25 mg of phenylephrine and P < 0.05 for 0.4 mg of phenylephrine), respectively. ScO2 then decreased ∼7% ( P < 0.001). Phenylephrine had no effect on SjvO2, PaCO2, or CMRO2. MAP increased after the administration of phenylephrine during low-intensity exercise (∼15%), but this was attenuated (∼10%) during high-intensity exercise ( P < 0.001). The reduction in ScO2 after administration of phenylephrine was attenuated during low-intensity exercise (−5%, P < 0.001) and abolished during high-intensity exercise (−3%, P = not significant), where PaCO2 decreased 7% ( P < 0.05) and CMRO2 increased 17% ( P < 0.05). These results suggest that the administration of phenylephrine reduced ScO2 but that the increased cerebral metabolism needed for moderately intense exercise eliminated that effect.

Role of thermogenesis in the regulation of energy balance in relation to obesity

1989 ◽  
Vol 67 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Jean Himms-Hagen
Keyword(s):  
Adipose Tissue ◽  
Energy Balance ◽  
Energy Expenditure ◽  
Brown Adipose Tissue ◽  
Thermal Balance ◽  
Prominent Feature ◽  
Thermic Effect Of Food ◽  
Brown Adipose ◽  
Effect Of Food ◽  
Thermic Effect

Obligatory thermogenesis is a necessary accompaniment of all metabolic processes involved in maintenance of the body in the living state, and occurs in ail organs. It includes energy expenditure involved in ingesting, digesting, and processing food (thermic effect of food (TEF)). At certain life stages extra energy expenditure for growth, pregnancy, or lactation would also be obligatory. Facultative thermogenesis is superimposed on obligatory thermogenesis and can be rapidly switched on and rapidly suppressed by the nervous system. Facultative thermogenesis is important in both thermal balance, in which control of thermoregulatory thermogenesis (shivering in muscle, nonshivering in brown adipose tissue (BAT)) balances neural control of heat loss mechanisms, and in energy balance, in which control of facultative thermogenesis (exercise-induced in muscle, diet-induced thermogenesis (DIT) in BAT) balances control of energy intake. Thermal balance (i.e., body temperature) is much more stringently controlled than energy balance (i.e., body energy stores). Reduced energy expenditure for thermogenesis is important in two types of obesity in laboratory animals. In the first type, deficient DIT in BAT is a prominent feature of altered energy balance. It may or may not be associated with hyperphagia. In a second type, reduced cold-induced thermogenesis in BAT as well as in other organs is a prominent feature of altered thermal balance. This in turn results in altered energy balance and obesity, exacerbated in some examples by hyperphagia. In some of the hyperphagic obese animals it is likely that the exaggerated obligatory thermic effect of food so alters thermal balance that BAT thermogenesis is suppressed. In all obese animals, deficient hypothalamic control of facultative thermogenesis and (or) food intake is implicated.Key words: thermogenesis, brown adipose tissue, energy balance, obesity, cold, thermoregulation, diet.

scholarly journals Psychological distress and its associated risk factors among university students

2020 ◽  
Vol 66 (4) ◽  
pp. 414-418
Author(s):  
Tingting Li ◽  
Xu Zhang ◽  
Mingming Chen ◽  
Rui Wang ◽  
Lianping He ◽  
...  
Keyword(s):  
Risk Factors ◽  
Psychological Distress ◽  
University Students ◽  
High Intensity ◽  
Education Level ◽  
High Intensity Exercise ◽  
Low Intensity ◽  
Significant Difference ◽  
Associated Risk Factors ◽  
Low Intensity Exercise

SUMMARY OBJECTIVE Psychological distress is an important mental health problem among university students. The goal of this study was to determine psychological distress and its associated risk factors among students in the Anhui province. METHODS A cross-sectional study was conducted in a sample of 1304 students. In this study, a self-administered questionnaire consisting of the general demography and General Health Questionnaire (GHQ-12) was completed. Psychological distress was assessed using the GHQ-12-item questionnaire. A dichotomous category split was imposed on the GHQ-12 for the purpose of analysis. A GHQ-12 score of 4 or higher indicated psychological distress. The data were analyzed by SPSS 20.0 system. RESULTS A total of 1304 samples were analyzed in this study. The results indicated that the education level of the father and mother was associated with the students’ psychological distress (P<0.001). A significant association was found between high-intensity exercise and low-intensity exercise and psychological distress. However, no significant difference was identified between gender and psychological distress (P=0.173). CONCLUSION The education level of parents, high-intensity exercise, and low-intensity exercise were associated with psychological distress. Our results suggest that it is indispensable to raise awareness of psychological disorders and its associated risk factors among university students. Further studies are required to develop appropriate interventions for high-risk groups.

Thermal responses during arm and leg and combined arm-leg exercise in water

1984 ◽  
Vol 56 (5) ◽  
pp. 1355-1360 ◽  
Author(s):  
M. M. Toner ◽  
M. N. Sawka ◽  
K. B. Pandolf
Keyword(s):  
Heat Flow ◽  
Exercise Intensity ◽  
Metabolic Responses ◽  
Low Intensity ◽  
Convective Heat Loss ◽  
High Exercise Intensity ◽  
Leg Exercise ◽  
Exercise Type ◽  
Type Of Exercise ◽  
Low Intensity Exercise

Thermal and metabolic responses were examined during exposures in stirred water at approximately 20, 26, and 33 degrees C while subjects were performing 45 min of either arm (A), leg (L), or combined arm-leg (AL) exercise. Eight males immersed to the neck completed a low exercise intensity for A exercise and both a low and high exercise intensity for L and AL exercise. During low-intensity exercise, final metabolic rate (M) for A, L, and AL exercise was not different (P greater than 0.05) between exercise type for each water temperature (Tw). In contrast final rectal temperatures (Tre) for A and AL exercise were significantly lower than L values for each Tw during low-intensity exercise. These findings were supported by both mean weighted skin temperature (Tsk) and mean weighted heat flow (Hc) values, which were greater during A than L for each Tw. During high-intensity exercise, final Tre values were lower (P less than 0.05) during AL compared with L exercise across all Tw. Final Tsk and Hc values were not different between each type of exercise, although M was significantly lower during L exercise in 20 degrees C water. These data suggest a greater conductive and convective heat loss during exercise utilizing the arms when compared with leg-only exercise.

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