The effects of a formal exercise training programme on salivary hormone concentrations and body composition in previously sedentary aging men
- Authors: Hayes, Lawrence , Grace, Fergal , Sculthorpe, Nicholas , Herbert, Peter , Ratcliffe, John , Kilduff, Liam , Baker, Julien
- Date: 2013
- Type: Text , Journal article
- Relation: SpringerPlus Vol. 2, no. 18 (2013), p. 1-5
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- Description: Alteration in body composition, physical function, and substrate metabolism occur with advancing age. These changes may be attenuated by exercise. This study examined whether twenty eight, previously sedentary males (62.5 +/- 5.3 years of age; body mass of 89.7 +/- 16.4 kg) adhering to the ACSM minimum guidelines for aerobic exercise for six weeks would improve exercise capabilities, body composition and salivary hormone profiles. After six weeks of adhering to the guidelines, salivary testosterone and vo(2max) (absolute and relative) increased (p < 0.05), whilst body fat percentage and body mass decreased (p < 0.05). Peak power output, fat free mass and cortisol values were not significantly different. Interestingly, salivary testosterone correlated inversely with body fat percentage (R(2) = .285, p = 0.011). These results suggest that despite previous inactivity, older males can achieve improvements in cardiorespiratory fitness, body composition and anabolism by adhering to simple lifestyle changes.
Resting steroid hormone concentrations in lifetime exercisers and lifetime sedentary males
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Herbert, Peter , Baker, Julien , Hullin, David , Kilduff, Liam , Grace, Fergal
- Date: 2015
- Type: Text , Journal article
- Relation: Aging Male Vol. 18, no. 1 (2015), p. 22-26
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- Description: INTRODUCTION: Advancing age in men is associated with a progressive decline in serum testosterone (T) and interactions between exercise, aging and androgen status are poorly understood. The primary aim of this study was to establish the influence of lifelong training history on serum T, cortisol (C) and sex hormone binding globulin (SHBG) in aging men. A secondary aim was to determine the agreement between serum and salivary measurement of steroid hormones in ageing men. METHODS: Serum and salivary steroid hormones (serum C, T and SHBG, and salivary measures of C and T) were determined and compared between two distinct groups; lifelong exercising males (LE [n = 20], 60.4 +/- 4.7 year) and age matched lifelong sedentary individuals (SED [n = 28], 62.5 +/- 5.3 years). RESULTS: T-test revealed a lack of significant differences for serum C or SHBG between LE and SED, while Mann-Whitney U revealed a lack of differences in total T (TT), bioavailable T (bio-T) or free testosterone (free-T). Further, salivary T (sal-T) did not correlate with serum markers of T in LE, SED, or when pooled (r = 0.040; p > 0.05). CONCLUSIONS: Findings from this investigation suggested that resting levels of serum T and calculated free-T was unable to distinguish between diverse lifelong training histories in aging men. Further, sal-T was not an appropriate indicator of serum T and calculated free-T values in older males and considerable caution should be exercised when interpreting sal-T measurements in aging males.
Critical difference applied to exercise-induced salivary testosterone and cortisol using enzyme-linked immunosorbent assay (ELISA): distinguishing biological from statistical change
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Young, John , Baker, Julien , Grace, Fergal
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Physiology and Biochemistry Vol. 70, no. 4 (2014), p. 991-996
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- Description: Due to its noninvasive, convenient, and practical nature, salivary testosterone (sal-T) and cortisol (sal-C) are frequently used in a clinical and applied setting. However, few studies report biological and analytical error and even fewer report the 'critical difference' which is the change required before a true biological difference can be claimed. It was hypothesized that (a) exercise would result in a statistically significant change in sal-C and sal-T and (b) the exercise-induced change would be within the critical difference for both salivary hormones. In study 1, we calculated the critical difference of sal-T and sal-C of 18 healthy adult males aged 23.2 +/- 3.0 years every 60 min in a seated position over a 12-h period (08:00-20:00 hours [study 1]). As proof-of-concept, sal-C and sal-T was also obtained pre and at 5 and 60 min post a maximal exercise protocols in a separate group of 17 healthy males (aged 20.1 +/- 2.8 years [study 2]). The critical difference of sal-T calculated as 90 %. For sal-C, the critical difference was 148 % (study 1). Maximal exercise was associated with a statistically significant (p < 0.05) changes in sal-T and sal-C. However, these changes were all within the critical difference range. Results from this investigation indicate that a large magnitude of change for sal-C and sal-T is required before a biologically significant mean change can be claimed. Studies utilizing sal-T and sal-C should appreciate the critical difference of these measures and assess the biological significance of any statistical changes.
Does chronic exercise attenuate age-related physiological decline in males?
- Authors: Hayes, Lawrence , Grace, Fergal , Sculthorpe, Nicholas , Herbert, Peter , Kilduff, Liam , Baker, Julien
- Date: 2013
- Type: Text , Journal article
- Relation: Research in Sports Medicine Vol. 21, no. 4 (2013), p. 343-354
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- Description: Alteration in body composition, physical function, and substrate metabolism occur with advancing age. These changes can be attenuated by exercise. This study evaluated whether master athletes (MA [n = 20]) would have improved exercise capabilities, anthropometry, and hormone profiles when compared with age-matched sedentary counterparts (S [n = 28]). The MA group was predominantly aerobically trained with some resistance exercise incorporated in their routine. The VO(2max), peak power output, and salivary testosterone was significantly higher (p < 0.05) in the MA group, while diastolic blood pressure, systolic blood pressure, and body fat percentage were lower (p < 0.05). Cortisol, fat free mass, (FFM) and total body mass were not significantly different between groups. Salivary testosterone correlated positively with VO(2max) (r(2) = .320), suggesting that increased aerobic capacity is linked with higher concentrations of testosterone. These results suggest that life-long exercise is associated with favorable body composition and attenuation of the age related decline in testosterone.
Salivary hormone response to maximal exercise at two time points during the day
- Authors: Hayes, Lawrence , Grace, Fergal , Kilgore, Lon , Young, John , Baker, Julien
- Date: 2013
- Type: Text , Journal article
- Relation: Sport SPA Vol. 10, no. 1 (2013), p. 25-30
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- Description: The aim of the present study was to establish a relationship between the diurnal variations of testosterone and cortisol with the circadian rhythm of strength and power performance. Changes in salivary cortisol and salivary testosterone were measured after two different modes of maximal exercise (back squat and maximal 5 m sprint) at two different times of day to assess diurnal fluctuations. Seventeen physically active males volunteered as subjects. A randomized cross-over design was utilized and participants were allocated to a maximal back squat protocol at 09:00 and 17:00 h, and a maximal 5 m sprint protocol at 09:00 and 17:00 h separated by at least 48 h. Saliva samples were collected before exercise, at 5 and 60 min post exercise. Exercise performance displayed no time of day effect. No significant effect of exercise mode or time of day was observed in cortisol or testosterone concentrations. Cortisol concentrations were higher in the morning (p<0.001). Testosterone did not exhibit a significant time of day effect however, higher levels tended to be observed at 09:00 h. The data suggest that non weight trained individuals do not display a time of day effect for maximum squat or 5 m sprint performance, or the subsequent salivary hormonal response.
HIIT produces increases in muscle power and free testosterone in male masters athletes
- Authors: Herbert, Peter , Hayes, Lawrence , Sculthorpe, Nicholas , Grace, Fergal
- Date: 2017
- Type: Text , Journal article
- Relation: Endocrine Connections Vol. 6, no. 7 (2017), p. 430-436
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- Description: High-intensity interval training (HIIT) improves peak power output (PPO) in sedentary aging men but has not been examined in masters endurance athletes. Therefore, we investigated whether a six-week program of low-volume HIIT would (i) improve PPO in masters athletes and (ii) whether any change in PPO would be associated with steroid hormone perturbations. Seventeen male masters athletes (60 +/- 5 years) completed the intervention, which comprised nine HIIT sessions over six weeks. HIIT sessions involved six 30-s sprints at 40% PPO, interspersed with 3 min active recovery. Absolute PPO (799 +/- 205 W and 865 +/- 211 W) and relative PPO (10.2 +/- 2.0 W/kg and 11.0 +/- 2.2 W/kg) increased from pre- to post-HIIT respectively (P < 0.001, Cohen's d = 0.32-0.38). No significant change was observed for total testosterone (15.2 +/- 4.2 nmol/L to 16.4 +/- 3.3 nmol/L (P = 0.061, Cohen's d = 0.32)), while a small increase in free testosterone occurred following HIIT (7.0 +/- 1.2 ng/dL to 7.5 +/- 1.1 ng/dL pre-to post-HIIT (P = 0.050, Cohen's d = 0.40)). Six weeks' HIIT improves PPO in masters athletes and increases free testosterone. Taken together, these data indicate there is a place for carefully timed HIIT epochs in regimes of masters athletes.
Poor levels of agreement between serum and saliva testosterone measurement following exercise training in aging men
- Authors: Hayes, Lawrence , Sculthorpe, Nicholas , Herbert, Peter , Baker, Julien , Hullin, David , Kilduff, Liam , Grace, Fergal
- Date: 2015
- Type: Text , Journal article
- Relation: Aging Male Vol. 18, no. 2 (2015), p. 67-70
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- Description: Testosterone (T) is a biologically important androgen that demonstrates a widely-known natural decline with advancing age. The use of salivary T (sal-T), as a determinant of systemic T, has shown promising results in recent years. However, the strength of the salivary-serum T relationship may be affected by measurement method and binding capacity with salivary proteins. The potential influence exercise may impact on this relationship is unstudied in aging men. Therefore, the aim of the present investigation was to examine the relationship of the delta change (Delta) in sal-T with Deltaserum T following six weeks exercise training. Fifteen sedentary (SED) males (aged 60.4 +/- 5.0 years of age) and 20 lifelong exercising (LE) males (60.4 +/- 4.7 years of age) were participated. Pearson's correlation coefficient revealed sal-T did not correlate with total testosterone (TT), sex hormone binding globulin (SHBG), bioactive T (bio-T), or free T (free-T) at week 0 or week 6. Deltasal-T did not correlate with DeltaTT, DeltaSHBG, Deltabio-T or Deltafree-T (r = 0.271, p = 0.180; r = 0.197, p = 0.335; r = 0.258, p = 0.205; and r = 0.257, p = 0.205, respectively). In conclusion, poor levels of agreement existed between saliva and serum measurements of T in response to exercise amongst aging men.