Hormonudskillelse og træning (GH og T)

[MRburns]

For noget tid siden læste jeg i et fitness blad, at væksthormon (GH) havde en positiv indflydelse på testosteronets (T) effekt på hypertrofi. Så jeg gav mig til at søge lidt på pubmed, for at se hvad jeg kunne finde. De studier jeg så fandt gav anledning til en del forvirring i forhold til hvad jeg tidligere har læst omkring det optimale antal reps og så de forhold som har indflydelse på udskilningen af hormoner. De to første studier har fået mig til at overveje om tung træning er den rigtige måde at træne på, derfor opretter jeg en anden tråd til den diskussion, da det ikke umiddelbart har noget med hormonudskillelsen at gøre.

Som sådan er det vel ikke noget nyt i at lav intensitet og høj volumen øger udskilningen af GH. Mit spørgsmål er så, har GH en effekt på hypertrofi som er værd at gå efter, eller skal man udelukkende forsøge at optimere sin træning så man øger udskilningen af T.

1) Hvis det er sandt at GH har en positiv interaktionseffekt på T og dermed øger effekten af T, så er det vil en god ting at træner efter en øget udskillelse af GH. Er der noget om denne påstand.

2) GH skulle øge kroppens evne til at bruge fedt som brændstof. Derfor vil et øget niveau af GH under træningen medfører at jeg tærer mere på mine fedtdepoter – og det vil for mig være gavnligt. Kan det spille nogen rolle

3) Ud fra hvad jeg har læst på mol, så er det tung styrketræning fx 5*5 eller 3*10 mange singles osv, som skulle være det optimale for at fremme T niveauet. Nu har jeg fundet nogle studier (specielt de tre nederste) som ikke ligefrem underbygger påstanden. Måske er det nogle dårlige studier, det har jeg ikke den faglige viden til at kunne vurdere. Er det videnskabelig bevidst at tung træning øger udskillelsen af T – eller er det bare en træningsfloskel ?

J Strength Cond Res. 2004 Nov;18(4):730-7.

Muscular adaptations to combinations of high- and low-intensity resistance exercises.

Goto K, Nagasawa M, Yanagisawa O, Kizuka T, Ishii N, Takamatsu K.

Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.

Acute and long-term effects of resistance-training regimens with varied combinations of high- and low-intensity exercises were studied. Acute changes in the serum growth hormone (GH) concentration were initially measured after 3 types of regimens for knee extension exercise: a medium intensity (approximately 10 repetition maximum [RM]) short interset rest period (30 s) with progressively decreasing load ("hypertrophy type"); 5 sets of a high-intensity (90% of 1RM) and low-repetition exercise ("strength type"); and a single set of low-intensity and high-repetition exercise added immediately after the strength-type regimen ("combi-type"). Postexercise increases in serum GH concentration showed a significant regimen dependence: hypertrophy-type > combi-type > strength-type (p < 0.05, n = 8). Next, the long-term effects of periodized training protocols with the above regimens on muscular function were investigated. Male subjects (n = 16) were assigned to either hypertrophy/combi (HC) or hypertrophy/ strength (HS) groups and performed leg press and extension exercises twice a week for 10 weeks. During the first 6 weeks, both groups used the hypertrophy-type regimen to gain muscular size. During the subsequent 4 weeks, HC and HS groups performed combi-type and strength-type regimens, respectively. Muscular strength, endurance, and cross sectional area (CSA) were examined after 2, 6, and 10 weeks. After the initial 6 weeks, no significant difference was seen in the percentage changes of all variables between the groups. After the subsequent 4 weeks, however, 1RM of leg press, maximal isokinetic strength, and muscular endurance of leg extension showed significantly (p < 0.05) larger increases in the HC group than in the HS group. In addition, increases in CSA after this period also tended to be larger in the HC group than in the HS group (p = 0.08). The results suggest that a combination of high- and low-intensity regimens is effective for optimizing the strength adaptation of muscle in a periodized training program.

PMID: 15574075 [PubMed - indexed for MEDLINE]

Konklusion: tung træning skal afsluttes med et let sæt med mange gentagelser.

A single set of low intensity resistance exercise immediately following high intensity resistance exercise stimulates growth hormone secretion in men.

J Sports Med Phys Fitness. 2003 Jun;43(2):243-9.

Goto K, Sato K, Takamatsu K.

Doctoral Program in Health and Sport Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan.

AIM: The purpose of the present study was to examine the effects of an additional set immediately following high intensity resistance exercise on growth hormone (GH) response. METHODS: Subjects (n=8) performed 4 resistance exercise protocols (bilateral knee extension exercise) on separate days. The protocols were categorized into 2 types of protocol, namely "Strength-up type (S-type)" and "Combination type (Combi-type)". The S-type was resistance exercise which consisted of 5 sets at 90% of 1 repetition maximum (RM) with 3-min rest periods between sets, whereas the Combi-type is a training protocol which adds an additional set (either 50% of 1 RM [C50-type], 70% of 1 RM [C70-type] or 90% of 1 RM [C90-type]) to the S-type. Serum GH concentration and blood lactate concentration were determined pre-exercise and at 0-60 min postexercise. Relative changes in thigh girth and maximal unilateral isometric strength were determined pre-exercise and immediately postexercise. RESULTS: The increasing values of GH concentration (DGH) in the S-type was the lowest of all protocols. On the other hand, DGH in the C50-type showed a significantly (p<0.05) higher increase than in the S-type and C90-type, and a relatively higher increase than in the C70-type. CONCLUSION: These results suggests that a high intensity, low volume training protocol to induce neural adaptation resulted in little GH response, but GH secretion was increased by performing a single set of low intensity resistance exercise at the end of a series of high intensity resistance sets.

PMID: 12853908 [PubMed - indexed for MEDLINE]

Konklusion kombiner tung og let træning

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Hormonal responses after various resistance exercise protocols.

Smilios I, Pilianidis T, Karamouzis M, Tokmakidis SP.

Department of Physical Education & Sport Science, Democritus University of Thrace, Komotini, Greece.

PURPOSE: This study examined the effects of the number of sets on testosterone, cortisol, and growth hormone (hGH) responses after maximum strength (MS), muscular hypertrophy (MH), and strength endurance (SE) protocols. METHODS: Eleven young men performed multi-joint dynamic exercises using MS (5 reps at 88% of one-repetition maximum (1-RM), 3-min rest) and MH (10 reps at 75% of 1-RM, 2-min rest) protocols with 2, 4, and 6 sets at each exercise; and an SE (15 reps at 60% of 1-RM, 1-min rest) with 2 and 4 sets. Hormonal concentrations were measured before exercise, immediately after, and at 15 and 30 min of recovery. RESULTS: The number of sets did not affect the hormonal responses after the MS protocol. Cortisol and hGH were higher (P < 0.05) after the four-set compared with the two-set sessions in the MH and SE protocols. No differences were observed between the six-set and the four-set sessions in the MH protocol. Cortisol and hGH were higher (P < 0.05) than the MS after the SE and MH protocols, and only when four and six sets were performed in the latter. hGH was higher than the MH after the SE protocol, whether two or four sets were executed, whereas cortisol (P < 0.05) was higher after the SE protocol only when two sets were performed. Testosterone did not change with any workout. CONCLUSION: The number of sets functions up to a point as a stimulus for increased hormonal concentrations in order to optimize adaptations with MH and SE protocols, and has no effect on a MS protocol. Furthermore, the number of sets may differentiate long-term adaptations with MS, MH, and SE protocols causing distinct hormonal responses.

GH bliver påvirket af mange gentagelser og gerne mange sæt. T niveauet lader sig ikke påvirke af nogen af træningsformerne – heller ikke tung træning 5RM og seks sæt.

Acute hormonal responses to two different fatiguing heavy-resistance protocols in male athletes

K. Hakkinen and A. Pakarinen

Department of Biology of Physical Activity, University of Jyvaskyla, Finland.

To examine endogenous hormonal responses to heavy-resistance exercise, ten male strength athletes performed two fatiguing but different types of sessions on separate days. In session A the loads for the leg extensor muscles in the squat-lift exercise were maximal so that the subjects performed 20 sets at 1 repetition maximum (RM) (20 x 1 RM x 100%), whereas during session B the loads were submaximal (70%) but the subjects performed each of the 10 sets until the RM (i.e., 10 repetitions/set or 10 x 10 x 70%). The recovery time between the sets was always 3 min. A decrease of 10.3 +/- 4.7% (P < 0.001) occurred in the squat-lift in 1 RM during session A, whereas session B led to a decrease of 24.6 +/- 18.9% (P < 0.001) in 10 RM. Increases in the concentrations of serum total and free testosterone (P < 0.05 and 0.05, respectively), cortisol (P < 0.001), and growth hormone (GH, P < 0.001) were observed during session B, whereas the corresponding changes during session A were statistically insignificant except for the relatively slight increase (P < 0.01) in serum GH level. The significant (P < 0.001) increase in blood lactate concentration during the two sessions correlated significantly (P < 0.01) with the increase in serum GH concentration. The morning values of serum testosterone and free testosterone were significantly (P < 0.05-0.001) lowered on the 1st and 2nd rest days after the sessions.(ABSTRACT TRUNCATED AT 250 WORDS)

Som jeg læser det, så medfører tung træning – altså singles – ikke nogen signifikant ændring i T niveauet. Hvorimod GH stiger som følge af de mange sæt.

Hormonal Responses and Adaptations to Resistance Exercise and Training.

Kraemer WJ, Ratamess NA.

Human Performance Laboratory, Department of Kinesiology and Department of Physiology and Neurobiology and School of Medicine, University of Connecticut, Storrs, Connecticut, USASchool of Biomedical and Sports Science, Edith Cowan University, Joondalup, Western Australia, Australia.

Resistance exercise has been shown to elicit a significant acute hormonal response. It appears that this acute response is more critical to tissue growth and remodelling than chronic changes in resting hormonal concentrations, as many studies have not shown a significant change during resistance training despite increases in muscle strength and hypertrophy. Anabolic hormones such as testosterone and the superfamily of growth hormones (GH) have been shown to be elevated during 15-30 minutes of post-resistance exercise providing an adequate stimulus is present. Protocols high in volume, moderate to high in intensity, using short rest intervals and stressing a large muscle mass, tend to produce the greatest acute hormonal elevations (e.g. testosterone, GH and the catabolic hormone cortisol) compared with low-volume, high-intensity protocols using long rest intervals. Other anabolic hormones such as insulin and insulin-like growth factor-1 (IGF-1) are critical to skeletal muscle growth. Insulin is regulated by blood glucose and amino acid levels. However, circulating IGF-1 elevations have been reported following resistance exercise presumably in response to GH-stimulated hepatic secretion. Recent evidence indicates that muscle isoforms of IGF-1 may play a substantial role in tissue remodelling via up-regulation by mechanical signalling (i.e. increased gene expression resulting from stretch and tension to the muscle cytoskeleton leading to greater protein synthesis rates). Acute elevations in catecholamines are critical to optimal force production and energy liberation during resistance exercise. More recent research has shown the importance of acute hormonal elevations and mechanical stimuli for subsequent up- and down-regulation of cytoplasmic steroid receptors needed to mediate the hormonal effects. Other factors such as nutrition, overtraining, detraining and circadian patterns of hormone secretion are critical to examining the hormonal responses and adaptations to resistance training.

Ifølge kilden er det høj volumen, moderet til høj intensitiet og korte pause, som har den største effekt på hormonudskillelsen generelt.