Growth hormone responses to 3 different exercise bouts in 18- to 25- and 40- to 50-year-old men

2008 ◽  
Vol 33 (4) ◽  
pp. 706-712 ◽  
Author(s):  
Kate L. Gilbert ◽  
Keith A. Stokes ◽  
George M. Hall ◽  
Dylan Thompson
Keyword(s):  
Growth Hormone ◽  
Resistance Exercise ◽  
Blood Lactate ◽  
Maximal Oxygen Consumption ◽  
Exercise Bout ◽  
Random Order ◽  
Young Group ◽  
Cycle Ergometer ◽  
Middle Aged ◽  
Time Curve

Exercise is a potent stimulus for growth hormone (GH) release, although aging appears to attenuate this response. The aim of this study was to investigate GH responses to different exercise stimuli in young and early middle-aged men. Eight men aged 18–25 y and 8 men aged 40–50 y completed 3 trials, at least 7 days apart, in a random order: 30 s cycle-ergometer sprint (sprint), 30 min resistance exercise bout (resistance), 30 min cycle at 70% maximal oxygen consumption (endurance). Blood samples were taken pre-, during, and post-exercise, and area under the GH vs. time curve was calculated for a total of 120 min. Mean blood lactate concentrations and percentage heart rate maximum at which the participants were working were not different between groups in any of the trials. In both groups, blood lactate concentrations were significantly lower in the endurance trial than in the sprint and resistance trials. There were no significant differences in resting GH concentration between groups or trials. GH AUC was significantly greater in the young group than the early middle-aged group, in both sprint (531 (±347) vs. 81 (±54) µg·L–1 per 120 min, p = 0.003) and endurance trials (842 (±616) vs. 177 (±137) µg·L–1 per 120 min, p = 0.010). Endurance exercise elicits a greater GH response than sprint and resistance exercise; however, aging per se, factors associated with aging, or an inability to achieve a sufficient absolute exercise intensity results in a smaller GH response to an exercise stimulus in early middle-aged men.

scholarly journals Metabolic, Cardiac, and Hemorheological Responses to Submaximal Exercise under Light and Moderate Hypobaric Hypoxia in Healthy Men

Biology ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 144
Author(s):  
Hun-Young Park ◽  
Jeong-Weon Kim ◽  
Sang-Seok Nam
Keyword(s):  
Oxygen Uptake ◽  
Blood Lactate ◽  
Minute Ventilation ◽  
Random Order ◽  
Cycle Ergometer ◽  
Submaximal Exercise ◽  
Erythrocyte Deformability ◽  
Moderate Hypoxia ◽  
Healthy Men ◽  
Significant Difference

We compared the effects of metabolic, cardiac, and hemorheological responses to submaximal exercise under light hypoxia (LH) and moderate hypoxia (MH) versus normoxia (N). Ten healthy men (aged 21.3 ± 1.0 years) completed 30 min submaximal exercise corresponding to 60% maximal oxygen uptake at normoxia on a cycle ergometer under normoxia (760 mmHg), light hypoxia (596 mmHg, simulated 2000 m altitude), and moderate hypoxia (526 mmHg, simulated 3000 m altitude) after a 30 min exposure in the respective environments on different days, in a random order. Metabolic parameters (oxygen saturation (SPO2), minute ventilation, oxygen uptake, carbon dioxide excretion, respiratory exchange ratio, and blood lactate), cardiac function (heart rate (HR), stroke volume, cardiac output, and ejection fraction), and hemorheological properties (erythrocyte deformability and aggregation) were measured at rest and 5, 10, 15, and 30 min after exercise. SPO2 significantly reduced as hypoxia became more severe (MH > LH > N), and blood lactate was significantly higher in the MH than in the LH and N groups. HR significantly increased in the MH and LH groups compared to the N group. There was no significant difference in hemorheological properties, including erythrocyte deformability and aggregation. Thus, submaximal exercise under light/moderate hypoxia induced greater metabolic and cardiac responses but did not affect hemorheological properties.

Abstract 598: Irisin, a Novel Hormone, and Its Response to Increasing Exercise Intensity in Young Healthy Subjects

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Alexandra Cooke ◽  
Yessica H Gomez ◽  
Andrew F Mutter ◽  
Christos S Mantzoros ◽  
Stella S Daskalopoulou
Keyword(s):  
Healthy Subjects ◽  
Energy Demand ◽  
Maximal Exercise ◽  
Therapeutic Potential ◽  
Maximal Oxygen Consumption ◽  
Random Order ◽  
Absolute Intensity ◽  
Time Curve ◽  
Post Exercise ◽  
Maximal Intensity

Introduction: Irisin, a recently discovered hormone, has been shown to induce white adipose tissue browning, enhancing energy expenditure and possibly mediating some of the beneficial effects of exercise. We aimed to estimate a) the timeframe of changes in plasma irisin levels after acute maximal exercise, b) the effect of different exercise intensities on irisin levels immediately post-exercise, and c) the effect of smoking (chronic and acute) on exercise-induced irisin release. Methods: a) 4 healthy subjects (22.5±1.73 years) underwent maximal exercise to attain maximal oxygen consumption (VO 2max ). Blood was drawn at pre-specified intervals to define the time curve of irisin changes over a 24-hr period; b) 35 healthy, non-smoking (23.0±3.3 years) men and women (n=20/15) underwent three exercise protocols ≥48 hrs apart, in random order: 1) maximal intensity (VO 2max ), 2) relative intensity (70% VO 2max , 10 mins); and 3) absolute intensity (75W output, 10 mins). Blood was drawn immediately pre- and 3 mins post-exercise; c) In 20 smokers irisin levels were measured pre- and 3 mins post-maximal exercise after 12 hrs abstinence from smoking on two separate days 1) continued abstinence (chronic smoking) and 2) after smoking one cigarette pre-exercise (acute smoking), compared to 10 non-smokers. Results: a) Irisin levels increased by 35% 3 mins post-exercise, then dropped and remained constant; b) Irisin levels post-exercise were significantly higher than pre-exercise after all intensities (all, P<.001). Post-pre exercise differences in irisin levels were significantly different between exercise intensities (P=.001), with the greatest increase after maximal intensity (P=.004 vs. relative, and absolute). Higher VO 2max correlated with a greater post-pre exercise difference in irisin levels after maximal exercise; c) Smoking study analyses are underway. Conclusions: Plasma irisin levels were acutely elevated in response to exercise, with a greater increase after maximal exercise. Higher VO 2max was associated with greater irisin release. These findings suggest that irisin release could be a function of muscle energy demand. Future studies need to determine the underlying mechanisms of irisin release and explore irisin’s therapeutic potential.

Effect of endurance exercise on myosin heavy chain gene regulation in human skeletal muscle

1999 ◽  
Vol 276 (2) ◽  
pp. R414-R419 ◽  
Author(s):  
D. Sean O’Neill ◽  
Donghai Zheng ◽  
Wade K. Anderson ◽  
G. Lynis Dohm ◽  
Joseph A. Houmard
Keyword(s):  
Skeletal Muscle ◽  
Myosin Heavy Chain ◽  
Heavy Chain ◽  
Human Skeletal Muscle ◽  
Contractile Activity ◽  
Maximal Oxygen Consumption ◽  
Exercise Bout ◽  
Cycle Ergometer ◽  
Chain Gene ◽  
Exercise Period

The purpose of this study was to determine the effect of endurance-oriented exercise on myosin heavy chain (MHC) isoform regulation in human skeletal muscle. Exercise consisted of 1 h of cycle ergometer work per day at 75% maximal oxygen consumption for seven consecutive days. Muscle was obtained before the first bout of exercise, 3 h after the first bout of exercise, and before and 3 h after the final exercise bout on day 7( n = 9 subjects). No changes in MHC mRNA (I, IIa, IIx) were evident after the first exercise period. There was, however, a significant ( P < 0.05) decline (−30%) in MHC IIx mRNA 3 h after the final training bout. An interesting finding was that a higher pretraining level of MHC IIx mRNA was associated with a greater decline in the transcript before ( r = 0.68, P < 0.05) and 3 h after ( r = 0.82, P < 0.05) the final exercise bout. These findings suggest that MHC IIx mRNA is downregulated during the early phase of endurance-oriented exercise training in human skeletal muscle but only after repeated contractile activity. Pretraining MHC IIx mRNA content may influence the magnitude of this response.

scholarly journals Resistance Exercise Attenuates High-Fructose, High-Fat-Induced Postprandial Lipemia

2015 ◽  
Vol 8 ◽  
pp. NMI.S32106 ◽  
Author(s):  
Jessie R. Wilburn ◽  
Jeffrey Bourquin ◽  
Andrea Wysong ◽  
Christopher L. Melby
Keyword(s):  
Resistance Exercise ◽  
Postprandial Lipemia ◽  
Exercise Bout ◽  
Random Order ◽  
Net Energy ◽  
High Fat ◽  
High Fructose ◽  
Energy Compensation ◽  
Postprandial Lipemic Response ◽  
Fat Meal

Introduction Meals rich in both fructose and fat are commonly consumed by many Americans, especially young men, which can produce a significant postprandial lipemic response. Increasing evidence suggests that aerobic exercise can attenuate the postprandial increase in plasma triacylglycerols (TAGs) in response to a high-fat or a high-fructose meal. However, it is unknown if resistance exercise can dampen the postprandial lipemic response to a meal rich in both fructose and fat. Methods Eight apparently healthy men (Mean ± SEM; age = 27 ± 2 years) participated in a crossover study to examine the effects of acute resistance exercise on next-day postprandial lipemia resulting from a high-fructose, high-fat meal. Participants completed three separate two-day conditions in a random order: (1) EX-COMP: a full-body weightlifting workout with the provision of additional kilocalories to compensate for the estimated net energy cost of exercise on day 1, followed by the consumption of a high-fructose, high-fat liquid test meal the next morning (day 2) (~600 kcal) and the determination of the plasma glucose, lactate, insulin, and TAG responses during a six-hour postprandial period; (2) EX-DEF: same condition as EX-COMP but without exercise energy compensation on day 1; and (3) CON: no exercise control. Results The six-hour postprandial plasma insulin and lactate responses did not differ between conditions. However, the postprandial plasma TAG concentrations were 16.5% and 24.4% lower for EX-COMP (551.0 ± 80.5 mg/dL x 360 minutes) and EX-DEF (499.4 ± 73.5 mg/dL x 360 minutes), respectively, compared to CON (660.2 ± 95.0 mg/dL x 360 minutes) ( P < 0.05). Conclusions A single resistance exercise bout, performed ~15 hours prior to a high-fructose, high-fat meal, attenuated the postprandial TAG response, as compared to a no-exercise control condition, in healthy, resistance-trained men.

Cholinergic and opioid involvement in release of growth hormone during exercise and recovery

1993 ◽  
Vol 75 (2) ◽  
pp. 870-878 ◽  
Author(s):  
D. L. Thompson ◽  
J. Y. Weltman ◽  
A. D. Rogol ◽  
D. L. Metzger ◽  
J. D. Veldhuis ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Oxygen Consumption ◽  
Blood Lactate ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Exercise Bout ◽  
Peak Oxygen Consumption ◽  
Moderate Intensity ◽  
Moderate Intensity Exercise ◽  
Testing Period

Cholinergic and opioid pathways have been implicated as mediators of the increased growth hormone (GH) release observed during exercise. This study compared the GH responses induced by a moderate-intensity exercise bout during treatment with placebo (Plac), the opioid receptor antagonist naltrexone (Nalt), the indirect cholinergic agonist pyridostigmine (PD), or a combination of the two drugs (P + N). Ten active males served as subjects (age, 25.1 +/- 0.6 yr; wt, 79.7 +/- 2.5 kg; % body fat, 14.9 +/- 1.4; peak oxygen consumption, 46.2 +/- 2.7 ml.kg-1 x min-1). Blood samples were drawn at 5-min intervals during the 4.5-h testing period to determine the GH concentration. The testing period was divided as follows: 0600–700 h = baseline, 0700–0800 h = preexercise, 0800–0830 h = exercise, and 0830–1030 h = recovery. Drugs were administered 1 h before exercise (at 0700 h). Exercise consisted of 30 min of cycling at an individualized work load previously found to elicit a blood lactate concentration of 2.5 mM. Heart rate, oxygen consumption, blood lactate, and blood glucose were measured throughout the exercise period. Results indicated that neither the resting GH concentration nor the metabolic parameters during exercise were altered by the treatments. Peak serum GH concentration was not significantly altered by the treatments (range 7.3 +/- 2.0 to 12.6 +/- 4.4 micrograms/l).(ABSTRACT TRUNCATED AT 250 WORDS)

Human growth hormone response to repeated bouts of aerobic exercise

1997 ◽  
Vol 83 (5) ◽  
pp. 1756-1761 ◽  
Author(s):  
J. A. Kanaley ◽  
J. Y. Weltman ◽  
J. D. Veldhuis ◽  
A. D. Rogol ◽  
M. L. Hartman ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Aerobic Exercise ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Exercise Bout ◽  
Cycle Ergometer ◽  
Distribution Volume ◽  
Growth Hormone Response ◽  
Hormone Response ◽  
Deconvolution Analysis

Kanaley, J. A., J. Y. Weltman, J. D. Veldhuis, A. D. Rogol, M. L. Hartman, and A. Weltman. Human growth hormone response to repeated bouts of aerobic exercise. J. Appl. Physiol. 83(5): 1756–1761, 1997.—We examined whether repeated bouts of exercise could override growth hormone (GH) auto-negative feedback. Seven moderately trained men were studied on three occasions: a control day (C), a sequential exercise day (SEB; at 1000, 1130, and 1300), and a delayed exercise day (DEB; at 1000, 1400, and 1800). The duration of each exercise bout was 30 min at 70% maximal O2 consumption (V˙o 2 max) on a cycle ergometer. Standard meals were provided at 0600 and 2200. GH was measured every 5–10 min for 24 h (0800–0800). Daytime (0800–2200) integrated GH concentrations were ∼150–160% greater during SEB and DEB than during C: 1,282 ± 345, 3,192 ± 669, and 3,389 ± 991 min ⋅ μg ⋅ l−1for C, SEB, and DEB, respectively [SEB > C ( P < 0.06), DEB > C ( P < 0.03)]. There were no differences in GH release during sleep (2300–0700). Deconvolution analysis revealed that the increase in 14-h integrated GH concentration on DEB was accounted for by an increase in the mass of GH secreted per pulse (per liter of distribution volume, lv): 7.0 ± 2.9 and 15.9 ± 2.6 μg/lv for C and DEB, respectively ( P < 0.01). Comparison of 1.5-h integrated GH concentrations on the SEB and DEB days (30 min exercise + 60 min recovery) revealed that, with each subsequent exercise bout, GH release apparently increased progressively, with a slightly greater increase on the DEB day [SEB vs. DEB: 497 ± 162 vs. 407 ± 166 ( bout 1), 566 ± 152 vs. 854 ± 184 ( bout 2), and 633 ± 149 vs. 1,030 ± 352 min ⋅ μg ⋅ l−1( bout 3), P < 0.05]. We conclude that the GH response to acute aerobic exercise is augmented with repeated bouts of exercise.

Growth hormone pulsatility profile characteristics following acute heavy resistance exercise

2001 ◽  
Vol 91 (1) ◽  
pp. 163-172 ◽  
Author(s):  
Bradley C. Nindl ◽  
Wesley C. Hymer ◽  
Daniel R. Deaver ◽  
William J. Kraemer
Keyword(s):  
Growth Hormone ◽  
Resistance Exercise ◽  
Kidney Diseases ◽  
Detection System ◽  
Human Growth ◽  
Exercise Bout ◽  
High Volume ◽  
Diagnostic Systems ◽  
Heavy Resistance Exercise ◽  
Profile Characteristics

This investigation examined the hypothesis that acute heavy resistance exercise (AHRE) would increase overnight concentrations of circulating human growth hormone (hGH). Ten men (22 ± 1 yr, 177 ± 2 cm, 79 ± 3 kg, 11 ± 1% body fat) underwent two overnight blood draws sampled every 10 min from 1700 to 0600: a control and an AHRE condition. The AHRE was conducted from 1500 to 1700 and was a high-volume, multiset exercise bout. Three different immunoassays measured hGH concentrations: the Nichols immunoradiometric assay (Nichols IRMA), National Institute of Diabetes and Digestive and Kidney Diseases radioimmunoassay (NIDDK RIA), and the Diagnostic Systems Laboratory immunofunctional assay (DSL IFA). The Pulsar peak detection system was used to evaluate the pulsatility profile characteristics of hGH. Maximum hGH was lower in the exercise (10.7 μg/l) vs. the control (15.4 μg/l) condition. Mean pulse amplitude was lower in the exercise vs. control condition when measured by the Nichols IRMA and the DSL IFA. A differential pattern of release was also observed after exercise in which hGH was lower in the first half of sleep but higher in the second half. We conclude that AHRE does influence the temporal pattern of overnight hGH pulsatility. Additionally, because of the unique molecular basis of the DSL IFA, this influence does have biological relevance because functionally intact molecules are affected.

Temporal Robustness of the Session Rating of Perceived Exertion

2016 ◽  
Vol 11 (8) ◽  
pp. 1088-1093 ◽  
Author(s):  
Joshua Christen ◽  
Carl Foster ◽  
John P. Porcari ◽  
Richard P. Mikat
Keyword(s):  
Steady State ◽  
Perceived Exertion ◽  
Ventilatory Threshold ◽  
Maximal Oxygen Consumption ◽  
Interval Training ◽  
Exercise Bout ◽  
Cycle Ergometer ◽  
Rating Of Perceived Exertion ◽  
Peak Power Output ◽  
User Friendly

Purpose:The session rating of perceived exertion (sRPE) has gained popularity as a “user friendly” method for evaluating internal training load. sRPE has historically been obtained 30 min after exercise. This study evaluated the effect of postexercise measurement time on sRPE after steady-state and interval cycle exercise. Methods:Well-trained subjects (N = 15) (maximal oxygen consumption = 51 ± 4 and 36 ± 4 mL/kg [cycle ergometer] for men and women, respectively) completed counterbalanced 30-minute steady-state and interval training bouts. The steady-state ride was at 90% of ventilatory threshold. The work-to-rest ratio of the interval rides was 1:1, and the interval segment durations were 1, 2, and 3 min. The high-intensity component of each interval bout was 75% peak power output, which was accepted as a surrogate of the respiratory compensation threshold, critical power, or maximal lactate steady state. Heart rate, blood lactate, and rating of perceived exertion (RPE) were measured. The sRPE (category ratio scale) was measured at 5, 10, 15, 20, 25, 30, and 60 min and 24 h after each ride using a visual analog scale (VAS) to prevent bias associated with specific RPE verbal anchors. Results:sRPE at 30 min postexercise followed a similar trend: steady state = 3.7, 1 min = 3.9, 2 min = 4.7, 3 min = 6.2. No significant differences (P > .05) in sRPE were found based on postexercise sampling times, from 5 min to 24 h postexercise. Conclusions:Postexercise time does not appear to have a significant effect on sRPE after either steady-state or interval exercise. Thus, sRPE appears to be temporally robust and is not necessarily limited to the 30-min-postexercise window historically used with this technique, although the presence or absence of a cooldown period after the exercise bout may be important.

scholarly journals Internal Loads, but Not External Loads and Fatigue, Are Similar in Young and Middle-Aged Resistance-Trained Males during High Volume Squatting Exercise †

2018 ◽  
Vol 3 (3) ◽  
pp. 45 ◽  
Author(s):  
John Fernandes ◽  
Kevin Lamb ◽  
Craig Twist
Keyword(s):  
Blood Lactate ◽  
Peak Power ◽  
Peak Velocity ◽  
High Volume ◽  
Young Group ◽  
Middle Aged ◽  
Internal Load ◽  
Volume Load ◽  
Related Response ◽  
External Loads

Little is known about the internal and external loads experienced during resistance exercise, or the subsequent fatigue-related response, across different age groups. This study compared the internal (heart rate, OMNI ratings of perceived exertion (RPE), session RPE) and external loads (peak velocity and power and volume load) during high volume squatting exercise (10 × 10 at 60% one-repetition maximum (1RM)) and the fatigue-related response (maximal voluntary contraction (MVC), voluntary activation (VA), resting doublet force, peak power, and blood lactate) in young (n = 9; age 22.3 ± 1.7 years) and middle-aged (n = 9; age 39.9 ± 6.2 years) resistance-trained males. All internal load variables and peak velocity illustrated unclear differences between groups during exercise. Peak power and volume load were likely higher in the young group compared to their middle-aged counterparts. The unclear differences in MVC, VA and blood lactate between groups after exercise were accompanied by very likely greater decrements in resting doublet force and peak power at 20 and 80% 1RM in the middle-aged group compared to the young group. These data indicate that internal load is not different between young and middle-aged resistance-trained males, though certain external load measures and the fatigue response are.

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