Metabolic, body temperature and hormonal responses to repeated periods of prolonged cycle-ergometer exercise in men

Kaciuba-Uściłko, H.; Kruk, Barbara; Szczypaczewska, Maria; Opaszowski, Benedykt; Stupnicka, E.; Bicz, B.; Nazar, K

doi:10.1007/bf00376435

Cited by 30 publications

(14 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…It is possible that circulating substrate (free fatty acids or glucose) was still available from the ®rst bout of exercise. Kaciuba-Uscilko et al (1992) observed increases in free fatty acid and glycerol concentrations (with reductions in glucose) in response to four 30-min bouts of exercise at 50% O 2max , each separated by 30-min recovery periods.…”

Section: Discussionmentioning

confidence: 83%

The Impact of heat exposure and repeated exercise on circulating stress hormones

Brenner

Zámečník²,

Shek³

et al. 1997

European Journal of Applied Physiology

View full text Add to dashboard Cite

To determine if heat exposure alters the hormonal responses to moderate, repeated exercise, 11 healthy male subjects [age = 27.1 (3.0) years; maximal oxygen consumption, VO2max = 47.6 (6.2) ml x kg x min(-1); mean (SD)] were assigned to four different experimental conditions according to a randomized-block design. While in a thermoneutral (23 degrees C) or heated (40 degrees C, 30% relative humidity) climatic chamber, subjects performed either cycle ergometer exercise (two 30-min bouts at approximately 50% VO2max, separated by a 45-min recovery interval, CEx and HEx conditions), or remained seated for 3 h (CS and HS conditions). Blood samples were analyzed for various exercise stress hormones [epinephrine (E), norepinephrine (NE), dopamine, cortisol and human growth hormone (hGH)]. Passive heating did not alter the concentrations of any of these hormones significantly. During both environmental conditions, exercise induced significant (P < 0.001) elevations in plasma E, NE and hGH levels. At 23 degrees C during bout 1: E = 393 (199) pmol x l(-1) (CEx) vs 174 (85) pmol x l(-1) (CS), NE = 4593 (2640) pmol x l(-1) (CEx) vs 1548 (505) pmol x l(-1) (CS), and hGH = 274 (340) pmol x l(-1) (CEx)vs 64 (112) pmol x l(-1) (CS). At 40 degrees C, bout 1: E = 596 (346) pmol x l(-1) (HEx) vs 323 (181) pmol x l(-1) (HS), NE = 7789 (5129) pmol x l(-1) (HEx) vs 1527 (605) pmol x l(-1) (HS), and hGH = 453 (494) pmol x l(-1) (HEx) vs 172 (355) pmol x l(-1) (HS). However, concentrations of plasma cortisol were increased only in response to exercise in the heat [HEx = 364 (168) nmol x l(-1) vs HS = 295 (114) nmol x l(-1)]. Compared to exercise at room temperature, plasma levels of E, NE and cortisol were all higher during exercise in the heat (P < 0.001 in all cases). The repetition of exercise did not significantly alter the pattern of change in cortisol or hGH levels in either environmental condition. However, repetition of exercise in the heat increased circulatory and psychological stress, with significantly (P < 0.001) higher plasma concentrations of E and NE. These results indicate a differential response of the various stress hormones to heat exposure and repeated moderate exercise.

show abstract

Section: Discussionmentioning

confidence: 83%

The Impact of heat exposure and repeated exercise on circulating stress hormones

Brenner

Zámečník²,

Shek³

et al. 1997

European Journal of Applied Physiology

View full text Add to dashboard Cite

show abstract

“…1d), the negative feedback mechanism might operate in the reduction in GH response to a subsequent resistance exercise. On the other hand, Kaciuba-Uscilko et al (1992) showed that four bouts of 30-min aerobic exercise separated by a 30-min rest period cause similar GH responses to all bouts, even though the GH concentration did not return to its pre-exercise level at the beginning of a subsequent bout. Kanaley et al (1997) demonstrated that the GH response to high-intensity aerobic exercise is augmented with repeated exercise.…”

Section: Discussionmentioning

confidence: 95%

Prior endurance exercise attenuates growth hormone response to subsequent resistance exercise

et al. 2005

View full text Add to dashboard Cite

This study examined the influence of prior endurance exercise on hormonal responses to subsequent resistance exercise. Ten males exercised on a cycle ergometer at 50% of maximal oxygen uptake for 60 min and subsequently completed a resistance exercise (bench and leg press, four sets at ten repetitions maximum with an interset rest period of 90 s). Alternatively, the subjects performed the protocol on a separate day with prior endurance exercise limited to 5 min. Blood was obtained before and after the endurance exercise, and 10, 20, and 30 min after the resistance exercise. Maximal isometric torque measured before and after endurance and resistance exercises showed no significant difference between trials. No significant difference was seen in the concentrations of glucose, lactate, testosterone, and cortisol between the trials, but free fatty acids (FFA) and growth hormone (GH) increased (P<0.01 and P<0.05, respectively) after 60 min of endurance exercise. Conversely, after the resistance exercise, GH was attenuated by 60 min of prior exercise (P<0.05). These results indicate that the GH response to resistance exercise is attenuated by prior endurance exercise. This effect might be caused by the increase in blood FFA concentration at the beginning of resistance exercise.

show abstract

“…This response is thought to be related to the overriding nonthermal influence on core temperature regulation associated with the work/rest transitions (219,243). In support of this hypothesis, it has been shown that intermittent exercise results in a progressive increase in core temperature although the magnitude of increase in the postexercise elevation in core temperature is reduced with successive work/rest intervals (219,(243)(244)(245)(246)(247).…”

Section: Calorimetic Evidence For Nonthermal Modulation Of Whole-bodymentioning

confidence: 94%

Human thermoregulation: separating thermal and nonthermal effects on heat loss

Glen¹

2010

Front Biosci

108

View full text Add to dashboard Cite

Human thermoregulatory control during heat stress has been studied at rest, during exercise and more recently during exercise recovery. Heat balance in the body is maintained by changes in the rate of heat loss via adjustments in skin blood flow and sweating. Independent of thermal control, the actions of nonthermal factors have important consequences in the control of heat loss responses during and following exercise. While the effect of these nonthermal factors is largely considered to be an inhibitory or excitatory stimulus which displaces the set-point about which temperature is regulated, their effects on human thermoregulatory control are far reaching. Many factors can affect the relative contribution of thermal and nonthermal influences to heat balance including exercise intensity, hemodynamic status, and the level of hyperthermia imposed. This review will characterize the physiological responses associated with heat stress and discuss the thermal and nonthermal influences on sweating and skin blood flow in humans. Further, recent calorimetric evidence for the understanding of thermal and nonthermal contributions to human heat balance will also be discussed.

show abstract

Metabolic, body temperature and hormonal responses to repeated periods of prolonged cycle-ergometer exercise in men

Cited by 30 publications

References 16 publications

The Impact of heat exposure and repeated exercise on circulating stress hormones

The Impact of heat exposure and repeated exercise on circulating stress hormones

Prior endurance exercise attenuates growth hormone response to subsequent resistance exercise

Human thermoregulation: separating thermal and nonthermal effects on heat loss

Contact Info

Product

Resources

About