Regional fat distribution (RFD) has been associated with metabolic derangements in populations with obesity. For example, upper body fat patterning is associated with higher levels of free testosterone (FT) and lower levels of sex-hormone binding globulin (SHBG). We sought to determine the extent to which this relationship was true in a healthy (i.e., non-obese) female population and whether RFD influenced androgen responses to resistance exercise. This study examined the effects of RFD on total testosterone (TT), FT, and SHBG responses to an acute resistance exercise test (ARET) among 47 women (22 ± 3 years; 165 ± 6 cm; 62 ± 8 kg; 25 ± 5 %BF; 23 ± 3 BMI). RFD was characterized by 3 separate indices: waist-to-hip ratio (WHR), ratio of upper arm fat to mid-thigh fat assessed with magnetic resonance imaging (MRI ratio), and ratio of subscapular to triceps ratio (SB/TRi ratio). Skinfolds were measured for the triceps, chest, subscapular, mid-axillary, suprailaic, abdomen, and thigh regions. The ARET consisted of 6 sets of 10 RM squats separated by 2-min rest periods. Blood was obtained pre- and post- ARET. TT, FT, and SHBG concentrations were determined by radioimmunoassay. Subjects were divided into tertiles from the indices of RFD, and statistical analyses were performed by an ANOVA with repeated measures (RFD and exercise as main effects). Significant (p < .05) increases following the AHRET were observed for TT (~25%), FT (~25%), and SHBG (4%). With multiple regression analysis, anthropometric measures significantly predicted pre- concentrations of FT, post-concentrations of TT, and pre-concentrations of SHBG. The SB/TRi and MRI ratios but not the WHR, were discriminant for hormonal concentrations among the tertiles. In young, healthy women, resistance exercise can induce transient increases in testosterone, and anthropometric markers of adiposity correlate with testosterone concentrations.
Bradley C. Nindl, William J. Kraemer, Lincoln A. Gotshalk, James O. Marx, Jeff S. Volek, Jill A. Bush, Keijo Häkkinen, Robert U. Newton, and Steve J. Fleck
Sean R. Schumm, N. Travis Triplett, Jeffrey M. McBride, and Charles L. Dumke
This investigation examined the anabolic-hormone response to carbohydrate (CHO) supplementation at rest and after resistance exercise. Nine recreationally trained men randomly underwent 4 testing conditions: rest with placebo (RPL), rest with CHO (RCHO), resistance exercise with placebo (EPL), and resistance exercise with CHO (ECHO). The resistance-exercise protocol was four sets of Smith machine squats with a 10-repetition-maximum load, with 90-s rests between sets. Participants then consumed either a placebo or CHO (24% CHO, 1.5 g/kg) drink. Blood was taken before exercise (Pre), immediately after testing (Post), and then 15 (15P), 30 (30P), and 60 (60P) min after drink ingestion. Blood was analyzed for cortisol, glucose, insulin, and total testosterone (TTST). Cortisol did not change significantly in any condition. Glucose concentrations increased significantly from Pre to 15P and 30P during RCHO and Pre to 15P, 30P, and 60P in ECHO (p ≤&.05). Insulin concentrations increased significantly from Pre to 15P, 30P, and 60P in the RCHO and ECHO conditions (p ≤&.05). There were no significant changes in TTST concentrations during RPL or RCHO. Both EPL and ECHO demonstrated a significant elevation in TTST concentrations from Pre to Post (p ≤&.05). During ECHO, TTST concentrations at 60P were significantly lower than Pre levels (p ≤&.05), but there were no significant treatment differences in TTST concentrations at any time point during the EPL and ECHO conditions. Ingesting CHO after resistance exercise resulted in decreased TTST concentrations during recovery, although the mechanism is unclear.
James A. Betts, Keith A. Stokes, Rebecca J. Toone, and Clyde Williams
Endocrine responses to repeated exercise have barely been investigated, and no data are available regarding the mediating influence of nutrition. On 3 occasions, participants ran for 90 min at 70% VO2max (R1) before a second exhaustive treadmill run at the same intensity (R2; 91.6 ± 17.9 min). During the intervening 4-hr recovery, participants ingested either 0.8 g sucrose · kg−1 · hr−1 with 0.3 g · kg−1 · hr−1 whey-protein isolate (CHO-PRO), 0.8 g sucrose · kg−1 · hr−1 (CHO), or 1.1 g sucrose · kg−1 · hr−1 (CHO-CHO). The latter 2 solutions therefore matched the former for carbohydrate or for available energy, respectively. Serum growth-hormone concentrations increased from 2 ± 1 μg/L to 17 ± 8 μg/L during R1 considered across all treatments (M ± SD; p ≤ .01). Concentrations were similar immediately after R2 irrespective of whether CHO or CHO-CHO was ingested (19 ± 4 μg/L and 19 ± 5 μg/L, respectively), whereas ingestion of CHO-PRO produced an augmented response (31 ± 4 μg/L; p ≤ .05). Growth-hormone-binding protein concentrations were unaffected by R1 but increased similarly across all treatments during R2 (from 414 ± 202 pmol/L to 577 ± 167 pmol/L; p ≤ .01), as was the case for plasma total testosterone (from 9.3 ± 3.3 nmol/L to 14.7 ± 4.6 nmol/L; p ≤ .01). There was an overall treatment effect for serum cortisol (p ≤ .05), with no specific differences at any given time point but lower concentrations immediately after R2 with CHO-PRO (608 ± 133 nmol/L) than with CHO (796 ± 278 nmol/L) or CHO-CHO (838 ± 134 nmol/L). Ingesting carbohydrate with added whey-protein isolate during short-term recovery from 90 min of treadmill running increases the growth-hormone response to a second exhaustive exercise bout of similar duration.
Kirsty J. Elliott-Sale, Adam S. Tenforde, Allyson L. Parziale, Bryan Holtzman, and Kathryn E. Ackerman
participating in a 72-hr fast had a marked reduction in total testosterone levels compared with prefast values ( Chan et al., 2003 ). In this same study, when men were given replacement doses of recombinant leptin during fasting, total testosterone was not reduced when compared with baseline, suggesting similar
Flavio A. Cadegiani, Pedro Henrique L. Silva, Tatiana C.P. Abrao, and Claudio E. Kater
), lactate (enzymatic assays), ferritin, vitamin B12, total testosterone, estradiol, serum insulin-like growth factor 1 (IGF-1), serum-free thyronine, and serum thyroid stimulating hormone (TSH; electrochemiluminescence assay), nocturnal 12-hour urine total and fractioned catecholamines and metanephrines
Diogo V. Leal, Lee Taylor, and John Hough
cortisol (∼97%) and total testosterone (31%), 11 it was assumed that a short-duration, high-intensity running protocol variant of the cycling 55/80 may be viable. This running variant, theoretically, could induce an acute elevation in plasma cortisol and testosterone when in a healthy state and also
Gabriel Barreto, Luana Farias de Oliveira, Tiemi Saito, Rafael Klosterhoff, Pedro Perim, Eimear Dolan, Rosa Maria R. Pereira, Patrícia Campos-Ferraz, Fernanda R. Lima, and Bryan Saunders
); nutritional status (vitamin B12, vitamin B, folic acid, total protein, albumin, and ferritin); and stress markers (uric acid, creatine kinase, free and total testosterone, cortisol, and thyroid-stimulating hormone; Supplementary Table 1 [available online]). The reference values provided by the hospital
(IU/L) 37 36 Alanine aminotransferase (IU/L) 29 28 Lactate dehydrogenase (IU/L) 463 435 Creatine kinase (IU/L) 342 211 Cortisol (ng/ml) 134.5 171.7 Total testosterone (ng/ml) 5.53 6.14 Note . HCHO = high carbohydrate; LCHF, low carbohydrate, high fat. Following these unsuccessful performances, the
Tony Adebero, Brandon John McKinlay, Alexandros Theocharidis, Zach Root, Andrea R. Josse, Panagiota Klentrou, and Bareket Falk
(percentage) change in testosterone displays a fluid effect, reflecting a decrease in serum but not in saliva. A partial explanation for this finding may be related to the fact that we measured total testosterone in serum but free testosterone in saliva. There was no group-by-fluid interaction indicating that
Blair Crewther, Christian Cook, John Fitzgerald, Michal Starczewski, Michal Gorski, and Joanna Orysiak
storage at −80°C. Total serum 25(OH)D concentration was determined using an enzyme-linked immunosorbent assay kit (DIAsource, Louvain-La-Neuve, Belgium). Serum total testosterone and total cortisol concentrations were also tested using enzyme-linked immunosorbent assay kits (DRG Instruments GmbH, Marburg