The Growth Hormone/Insulin-Like Growth Factor-I Axis in Exercise and Sport.

نویسندگان

  • James Gibney
  • Marie-Louise Healy
  • Peter H So Nksen
چکیده

The syndrome of adult GH deficiency and the effects of GH replacement therapy provide a useful model with which to study the effects of the GH/IGF-I axis on exercise physiology. Measures of exercise performance including maximal oxygen uptake and ventilatory threshold are impaired in adult GH deficiency and improved by GH replacement, probably through some combination of increased oxygen delivery to exercising muscle, increased fatty acid availability with glycogen sparing, increased muscle strength, improved body composition, and improved thermoregulation. In normal subjects, in addition to the long-term effects of GH/IGF-I status, there is evidence that the acute GH response to exercise is important in regulating substrate metabolism after exercise. Administration of supraphysiological doses of GH to athletes increases fatty acid availability and reduces oxidative protein loss, particularly during exercise, and increases lean body mass. Despite a lack of evidence that these metabolic effects translate to improved performance, GH abuse by athletes is widespread. Tests to detect GH abuse have been developed based on measurement in serum of 1) indirect markers of GH action, and 2) the relative proportions of the two major naturally occurring isoforms (20 and 22kDa) of GH. There is evidence that exercise performance and strength are improved by administration of GH and testosterone in combination to elderly subjects. The potential benefits of GH in these situations must be weighed against potential adverse effects.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effect of Six Months of Aerobic Exercise on Serum Levels of Insulin, Growth Hormone and Insulin-Like Growth Hormone 1 in Sedentary Obese Women

ABSTRACT            Background and Objectives: Inactivity, obesity and hormone disorders can lead to various diseases in obese and non-athletic individuals. The objective of this study was to investigate effects of six months of aerobic exercise on serum levels of insulin, growth hormone (GH) and insulin-like growth hormone 1 (IGF-1) in sedent...

متن کامل

The Effect of 8 Weeks Resistance Training With Low Load and High Load on Testosterone, Insulin-like Growth Factor-1, Insulin-like Growth Factor Binding Protein-3 Levels, and Functional Adaptations in Older Women

Objectives The loss of muscle mass in older adults is attributed to the impaired ability of the skeletal muscle in response to anabolic stimuli and the increased activation of the proteolytic signaling pathway. With increasing age, plasma concentrations of circulating anabolic hormones and growth factors, e.g. testosterone, Insulin-like Growth Factor-1 (IGF-1) and Insulin-like Growth Factor Bin...

متن کامل

The Effect of Eight Weeks Resistance Training With and Without Vascular Occlusion on Physical Fitness Indexes, Growth Hormone, and Insulin-like Growth Factor in Male Judokas

Purpose: The present study was conducted to investigate the effect of 8 weeks resistance training with and without vascular occlusion on physical fitness indexes, growth hormone, and Insulin-like growth factor 1 (IGF-1) in male judokas.  Methods: In this quasi-experimental study, 20 male judokas were divided into two groups: 1. Traditional resistance training along with judo training with...

متن کامل

Effect of eight weeks of resistance training on the expression of klotho protein and insulin-like growth factor 1 genes in slow twitch and fast twitch skeletal muscles of aged Wistar rats

Background and Aims: Klotho protein is a substance effective in increasing life expectancy. Moreover, it prevents muscle atrophy, osteoporosis, and cardiovascular disease. Therefore, the present aimed to assess changes in the expression of klotho protein and insulin-like growth factor 1 (IGF-1) genes in the muscles of aged Wistar rats after eight weeks of resistance training. Materials and Met...

متن کامل

The Effect of 12 Weeks Moderate Intensity Aerobic training on Serum Leptin, GH / IGF-1 in Adult and Immature Inactive Girl Students

Background & Aims: puberty is a process in which physical and physiological changes lead to changes in the child's body as an adult with reproductive capacity. The purpose of the present study was to investigate the effect of 12 weeks of moderate intensity aerobic training on serum leptin, growth hormone / Insulin-Like Growth Factor-1, in Mature and immature Inactive Girl Students. Materials &...

متن کامل

Brain-derived neurotrophic factor, insulin-like growth factor-I and its binding protein responses to a session of endurance exercise in healthy elderly men

  Purpose: This study investigated the effect of endurance activity on brain-derived neurotrophic   factor(BDNF), insulin-like growth factor 1(IGF-1) and its binding protein 3(IGFBP-3) in elderly   healthy individuals.   Materials and Methods: Eleven healthy old males (mean age of 68 ± 2.31 years old, height   of 177 ± 3.1 cm and weight of 79 ± 1.5 kg) were studied. Seventy two hours after maxi...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Endocrine reviews

دوره 28 6  شماره 

صفحات  -

تاریخ انتشار 2007