FIUID REGULATING HORMONES AT REST AND IN RESPONSE TO EXERCISE: RELATIONSHIPS TO MAXIMAL OXYGEN CONSUMPTION

1980 ◽  
Vol 21 (Supplement) ◽  
pp. S36
Author(s):  
B. J. Freund ◽  
E. M. Shizuru ◽  
G. M. Hashiro ◽  
J. R. Claybaugh
Keyword(s):  
Oxygen Consumption ◽  
Maximal Oxygen Consumption ◽  
Response To Exercise

Sex-based effects on the distribution of NK cell subsets in response to exercise and carbohydrate intake in adolescents

2006 ◽  
Vol 100 (5) ◽  
pp. 1513-1519 ◽  
Author(s):  
Brian W. Timmons ◽  
Mark A. Tarnopolsky ◽  
Oded Bar-Or
Keyword(s):  
Oxygen Consumption ◽  
Acute Exercise ◽  
Nk Cell ◽  
Maximal Oxygen Consumption ◽  
Exercise Immunology ◽  
Cell Counts ◽  
Flavored Water ◽  
Response To Exercise ◽  
Activation Marker Cd69 ◽  
Activation Status

Carbohydrate (CHO) supplementation and female sex independently influence the natural killer (NK) cell response to acute exercise. Consequently, this study sought to elucidate sex-based differences in the distribution of NK cell subsets (i.e., CD56dimand CD56bright) in response to exercise and CHO intake. Twenty-two healthy 14-yr-old girls ( n = 11) and boys ( n = 11) cycled for 60 min at 70% maximal oxygen consumption while drinking 6% CHO (CT) or flavored water (WT). Blood was collected at rest, during exercise (30 and 60 min), and during recovery (30 and 60 min) to identify CD3−CD56dimand CD3−CD56brightNK cells. The activation marker CD69 was also determined on CD3−CD56+cells. CD56dimresponses, expressed as proportions or cell counts, were greater ( P ≤ 0.01) in girls by 67 and 105%, respectively. CD56brightcell counts ( P = 0.006), but not CD56brightproportions ( P = 0.89), were greater in girls by 82%. Both CD56dimand CD56brightsubset responses, expressed as proportions or cell counts, were lower ( P ≤ 0.01) in CT vs. WT by 33–36%. The CD56bright-to-CD56dimratio decreased at 30 min of exercise but increased during recovery ( P < 0.001), with no effect of sex or CHO. Regardless of trial, CD3−CD56+cells expressed ∼18% higher levels of CD69 during recovery in girls but not boys ( P = 0.03), despite similar proportions and counts of CD69+cells. These results demonstrate sex-based differences in the distribution of NK cell subsets and activation status in response to exercise, but not CHO intake, and further support the need to control for sex in exercise immunology studies.

Catecholamine-fuel interrelationships during exercise in fasting men

1980 ◽  
Vol 48 (1) ◽  
pp. 109-113 ◽  
Author(s):  
J. M. Pequignot ◽  
L. Peyrin ◽  
G. Peres
Keyword(s):  
Maximal Oxygen Consumption ◽  
Plasma Catecholamines ◽  
Plasma Free Fatty Acid ◽  
Work Load ◽  
Bicycle Ergometer ◽  
Plasma Norepinephrine ◽  
Plasma Catecholamine ◽  
Adrenergic Response ◽  
Response To Exercise

Adrenergic response to exercise and the relationships between plasma catecholamines and blood energetic substrates were studied in sedentary men after 15 h of fasting. Subjects pedaled a bicycle ergometer until exhaustion at a work load approximating 80% maximal oxygen consumption. Working ability was diminished by the fast (P less than 0.025). Resting plasma norepinephrine level was increased by fasting. During exercise plasma epinephrine (E) and norepinephrine (NE) concentrations were more elevated in fasting subjects than in fed subjects. Plasma catecholamine (CA) levels in fasting men correlated with blood glucose, blood lactate, and plasma glycerol concentrations. There was no significative correlation between CA and plasma free fatty acid (FFA) levels. The increased adrenergic activity in fasting subjects correlated with reduced endurance time. This study emphasizes the role of CA release, probably combined with other hormonal factors, in the mobilization of energy substrates during submaximal exercise.

β-Adrenergic receptor number in human lymphocytes is inversely correlated with aerobic capacity

1998 ◽  
Vol 274 (6) ◽  
pp. E1106-E1112 ◽  
Author(s):  
Nobuharu Fujii ◽  
Sachiko Homma ◽  
Fumio Yamazaki ◽  
Ryoko Sone ◽  
Takeshi Shibata ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Aerobic Capacity ◽  
Adrenergic Receptor ◽  
Ventilatory Threshold ◽  
Human Lymphocytes ◽  
Mrna Level ◽  
Maximal Oxygen Consumption ◽  
Subsequent Degradation ◽  
Intracellular Compartments ◽  
Model Cell

In the present study, the relationships between β-adrenergic receptor (β-AR) expression and aerobic capacity evaluated by maximal oxygen consumption ([Formula: see text]) and oxygen consumption level at ventilatory threshold (V˙o 2@VT) were investigated. Seventeen physically untrained and 25 trained men participated in the study. After supine resting, the peripheral blood was sampled for preparation of lymphocytes, the model cell used to analyze the β-AR state. The total number of β-AR in lymphocytes (β-ARtotal) was inversely correlated with theV˙o 2 max( r = −0.368; P < 0.05) and theV˙o 2@VT ( r = −0.359; P < 0.05). Similar relationships were also observed between the number of β-AR in cell surface and both V˙o 2 max( r = −0.491; P < 0.05) andV˙o 2@VT ( r = −0.498; P < 0.05). However, no correlation was obtained between the number of β-AR in intracellular compartments and eitherV˙o 2 max orV˙o 2@VT. The β2-AR mRNA level quantified by the use of competitive reverse transcription-polymerase chain reaction was inversely correlated withV˙o 2@VT ( r = −0.567; P < 0.05) and positively correlated with β-ARtotal( r = 0.521; P < 0.05). These findings suggest that the β-AR number in lymphocytes is inversely correlated with aerobic capacity. This relationship may be explained by downregulation of β-AR, including internalization with subsequent degradation of the receptors and inhibition of the β-AR biosynthesis.

Responses to Intermittent Swimming Sets at Velocity Associated With max

2005 ◽  
Vol 30 (5) ◽  
pp. 543-553 ◽  
Author(s):  
Sebastien Libicz ◽  
Belle Roels ◽  
Gregoire P. Millet
Keyword(s):  
Oxygen Consumption ◽  
Maximal Oxygen Consumption ◽  
Interval Training ◽  
Swimming Velocity ◽  
Time Duration ◽  
Incremental Test ◽  
Large Variability ◽  
Equal Time ◽  
Physiological Adaptations ◽  
The Times

While the physiological adaptations following endurance training are relatively well understood, in swimming there is a dearth of knowledge regarding the metabolic responses to interval training (IT). The hypothesis tested predicted that two different endurance swimming IT sets would induce differences in the total time the subjects swam at a high percentage of maximal oxygen consumption [Formula: see text]. Ten trained triathletes underwent an incremental test to exhaustion in swimming so that the swimming velocity associated with [Formula: see text][Formula: see text] could be determined. This was followed by a maximal 400-m test and two intermittent sets at [Formula: see text] (a) 16 × 50 m with 15-s rest (IT50); (b) 8 × 100 m with 30-s rest (IT100). The times sustained above 95% [Formula: see text] (68.50 ± 62.69 vs. 145.01 ± 165.91 sec) and 95% HRmax (146.67 ± 131.99 vs. 169.78 ± 203.45 sec, p = 0.54) did not differ between IT50 and IT100 (values are mean ± SD). In conclusion, swimming IT sets of equal time duration at [Formula: see text] but of differing work-interval durations led to slightly different [Formula: see text] and HR responses. The time spent above 95% of [Formula: see text]max was twice as long in IT100 as in IT50, and a large variability between mean [Formula: see text] and HR values was also observed. Key words: interval training, maximal oxygen consumption, triathletes

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