Elite Sport and Biological Age Influence of Extensive or Regular Low to Moderate Exercise on Plasma Dhea-s and Cortisol in Ice-hockey Players

Based on common comments that elite players in soccer and ice-hockey often looked " older " than non-players of the same age, the authors examined the research literature but found that very few studies had been conducted in the area of elite sport and biological age. We therefore decided to conduct a pilot study comparing professional elite ice hockey players (EP) (22 males, M = 24.7 years) with a cohort of amateur players (AP) similar in age but from a lower competitive level (17 males, M = 25.4 years). Subjective ratings of motivational, attitude and emotional factors were combined with measurements of blood concentrations of DHEA-S, cortisol and the DHEA-S/cortisol ratio. DHEA-S and the DHEA-S/cortisol ratio were significantly higher (p < 0.01) while cortisol was unaffected in the AP compared with the EP group. Interpretation of the differences in adrenal hormones level indicated a biological age difference of around 10 years, with the EP group being older. Also, significant differences in the subjective ratings were noted with a more positive self-image, goal-image, attitude and emotions noted in the AP-group. As we have earlier demonstrated a decrease in biological age with mental training of these factors, further studies have to determine how much the higher biological age among the EP-group is due to exercise factors, ex-periential/personal factors or a combination of these and other factors. Hypothesis The process of biological aging goes faster in elite athletes compared with athletes from a lower level. If so, the difference in biological age depends on a combination of factors, of which two have been investigated in this study: 1) The frequency and intensity of the physical training (physical stress); 2) How differences in physical and mental stress levels effect psychological and personality dimensions with relations to biological age.

Extensive physical load during marathon in male athletes demonstrated that DHEA-S and cortisol were significantly increased (Ponjee, De Rooy, & Vader, 1994). During endurance training, DHEA-S increased in a dose-dependent manner at repeated running sessions for two hours. Cortisol was declined at all running sessions except at two hours, where the response was increased. The ratio of DHEA-S to cortisol was greater at rest and shorter running than at longer runs (Tremblay, Copeland, & Van Helder, 2005). Plasma DHEA was reported to increase with exercise, depending on the level of performance and intensity of the exercise (Cumming & Rebar, 1985;Valaido, Pantaleoni, & Valeiro, 1991). During 24 h running in men, DHEA-S, was increased over the course of 24 h, while falling level in DHEA-S may be possible using continuous aerobic exercise (Shimizu, Imanishi, Sugimoto, Takeda, Hirata, Andou, Morikawa, Suzuki, Watanabe, Okuta, Kawana, Namikawa, Suzuki, Watanabe, Okada, & Oht, 2011). Even though, cortisol was increased, changes in reactive oxygen spices were within normal range and the adaptation for antioxidation was good, indicating low or moderate stress to the body. In marathon runners, lowered cortisol and higher DHEA-S/cortisol ratio correlated with lowered leptin and thus more efficient energy expenditure for the best runners (Bobbert, Mai, Brechtel, Schult, Weger, Pfeiffer, Spranger, & Diederich, 2012). Evaluated from two separate independent studies, the plasma DHEA-S differs by approximately 14% when compared between endurance trained (Tremblay, Copeland, & Van Helder, 2005) and untrained (Nafziger, Bowlin, Jenkins, & Pearson, 1998) men at comparable age (31 years), the extensively trained men being lower at rest. The exercise in the trained men increased the DHEA-S in a dose-response manner with the greatest increase observed during 2 h run, comparable to the normal plasma level in untrained men.
In sportswomen, the ratio of DHEA to cortisol in saliva was increased by more than 30% during a 16 week training pro-gram with no difference between highly trained national and moderately trained regional groups. The athletes with the highest performance levels and greatest amount of training showed a less increase in the DHEA/cortisol ratio In contrast, the corresponding ratio was significantly lower in sedentary women (Filaire, Duch, & Lac, 1998). Cortisol did not change with the training over the season and was higher in the elite than in regional women. The training program increased significantly DHEA in all sportswomen.
The aim of this study was to compare elite with amateur icehockey players on cognitive and emotional issues and on the integrity of the HPA-axis by assessing the level of the adrenal hormones DHEA and cortisol in order to relate this to biological age.

Design
The purpose of this study was to monitor the effect of extensive or low to moderate training for two teams of male icehockey players, on blood concentrations of DHEA-S and cortisol, the DHEA-S/cortisol ratio and on experiential areas. Subjective data were collected from the SMAE factor questionnaire , which measures self-image, goal-Images, attitude and emotions.
One team consisted of highly-trained elite players, playing on national level, while the second team was a low to moderate trained regional ice hockey team. In accordance with previous presented research findings, the blood concentration ratio of DHEA-S/cortisol could serve as a biochemical marker and model for the anabolic/catabolic balance in sportsmen (Adlercreuts, Hakonen, Kuoopasalami, Naveri, Huhtanemi, Tikkanen, Remes, Dessypris, & Karvonen, 1986) with relation to biological age and to physiological and psychological well-being (Johansson & Uneståhl, 2005).

Subjects
A group of 39 healthy male volunteers took part in the study; 22 national and 17 regional ice-hockey players. The Elite Players (EP) had an average age of 24.7 years (19 -33) and the amateur players (AP) averaged at 25.4 years (17 -35). The EP group consisted of professional ice-hockey players, whereas the players in the AP group were amateur players with ordinary labour work during daytime. None of the participants were taking medication. Both groups were lead by professional coaches. The study was done during the second part of the winter season. All subjects in the EP group were on daily scheduled individual and team-based extensive training pro-gram except on match days and remained unchanged during the study. The training program during non-match days, comprised of two daily sessions of two hours each. Long-distance and exhausting continental bus transfers provided the transportation of the professional team players away from home competitions. Two competition games were performed on regular weekly basis during the season.
The players in the AP group followed a low or moderate training and competition program. Scheduled training was performed twice weekly for two hours and a competition game only once a week. Due to the local character and short-distance of transportation at competitions, co-transportation of team players was done by car. The content of the study protocol followed the recommendations of the local committee of human ethics. Each subject was informed of the test procedures and a written consent was obtained before study start.

Subjective Measures
Subjective self-reported measurements were made with the Swedish "SMAK" test, measuring the dimension: Self-image (S), Goal-images and Motivation (M), Attitudes (A) and Emotions (K). The Test was developed by Unestahl in the 1970's in cooperation with a number of national teams and the Swedish Olympic Teams 1976 and 1980. It has been used in a number of studies since then, among other in our last study about biological age (Johansson & Uneståhl, 2005). The test has good reliability and validity.
The S-factor (Self-Image) has statements related to Self-confidence as well as Self-esteem. The Goal-Images covers both Goal-level and Motivation. The Attitude scale has statements related to the Optimist-Not Optimist dimension, and also statements about Mental toughness and Resilience. The "E" factor is intended to measure "Internal Success" (transitory feelings of satisfaction, enjoyment, wellbeing and happiness). Changes in the SMAE factors through Mental Training have earlier been related to a number of psychophysiological and neuroimmunological factors (Johansson & Uneståhl, 2005;Bundzen, Leissner, Malinin, & Unestahl, 1996;Unestahl, Bundzen, Gavrilova, & Isakov, 2004;Bundzen, Gavrilova, Isakov, & Unestahl, 1998).

Collection of Blood and Analysis of Steroid Hormones
Venous blood samples were collected in the morning in Vacutainer ® tubes and 5 ml of blood were drawn for each sample. Blood samples were centrifuged immediately and stored frozen at -20˚C until assayed. All plasma samples were analysed in duplicate at an accredited local hospital department of clinical chemistry, according to standard laboratory methods for DHEA-S and cortisol (Beishuizen, Thijs, & Vermes, 2002;Normile, 1998;Labrie, Bélanger, Cusan , Gomez, & Candaz, 1997).

Statistical Analysis
All descriptive quantitative data were reported as mean ± SD. Comparisons between groups were made by unpaired student's t-test, while a two-tailed p value < 0.05 was considered as statistical significant.

Results
Mean plasma DHEA-S, cortisol and the ratio of DHEA-S/ cortisol for the EP and AP groups are given in Figures 1-3, respectively. The plasma concentration of DHEA-S in the EP group was significantly lower (<0.01) compared to the APgroup (Figure 1). The level of plasma cortisol was the same in both groups (Figure 2). The ratio of DHEA-S to cortisol was significantly higher in the EP-group compared with the AP group (p < 0.01), indicating elevated catabolism in professional players with sustained anabolism in amateurs (Figure 3). In the SMAE factor test all personal subjective factors were found to have significantly more positive ratings in the amateurs (AP); Self-image (p = 0.008), Goal images (p = 0.023), Attitudes (p = 0.032), and Emotions (p < 0.001) ( Table 1). Thus, in professionals the response of the HPA-axis followed the level of physical exercise reflected in a concomitant emotional and cognitive stress load.

Discussion
The 33% higher plasma DHEA-S in the AP group corresponds to a difference in biological age that according to normal reference observations is approximately 10 years below the average age range in the EP-group. The subjective ratings showed that the amateur ice-hockey players (AP) had significantly better self-images, were more goal-oriented and motivated, were interpreting life in a more positive way and had more of positive emotions. Whether, the difference in biological age was mainly due to exercise levels or cognitive and emotional factors or a combination of these cannot be directly determined based on this study. We know from an earlier study (Johansson & Uneståhl, 2005) that mental training of cognitive and emotional factors can raise the DHEA-S/Cortisol ratio (thus suggesting a lowering of the biological age). We also know from a previous study (Unestahl, Bundzen, Gavrilova, & Isakov, 2004) that systematic mental training can increase the tolerance for hard training and prevent the negative effects of "overtraining", partly due to improved rest and recovery skills. Thus, one contributing explanation of the results of our study could be that the lower intensity of training and matches in the amateur players gave them more time for rest and recover. The plasma DHEA-S and DHEA-S to cortisol ratio were concomitantly higher in the AP group, in spite of no difference in the plasma cortisol between groups.
Thus, the lower DHEA-S and the lower DHEA-S to cortisol ratio together with less positive subjective emotional experiences among the elite players, agrees with the negative influence of lowered levels of these hormones on both psychological and physiological, physical performance and health outcome (Endoh, Kristiansen, Casson, Buster, & Hornsby, 1996).
The results indicate that the amateurs are more adapted to a resonance state in a process that allows the individuals to feel the way they want to feel. Such a state of self-development underlies how to make meaning of daily experiences, and is reflected in the success of planning, thinking, and acting (Loevinger, 1976;Loevinge, Cohn, Bonneville, Redmore, Streich, Bonneville, Redmore, Streich, & Sargent, 1985;Cook-Greuter, 1999). The process is typically experienced as a seamless fit or harmony between the individual and the environment (Duran-Bush, Faubert, & Newburg, 2004).
In this regime, DHEA-S is a precursor hormone of more potent androgens involved to restore the consequences of catabolic activity and processes (Nafziger, Bowlin, Jenkins, & Pearson, 1998). Since DHEA-S is also a balancing hormone counteracting on the alleviated secretion of cortisol, e.g. after induction of an physiological state impressed by emotional comfort and well-being (Glaser, Brind, Vogelma, Eisner, Dillbeck, Walace, Chopra, & Orentreich, 1992;Johansson & Uneståhl, 2005), the DHEA-S/cortisol ratio has been used following the physical load in athletes (Ponjee, De Rooy, & Vader, 1994;Trembaly, Copeland, & Van Helder, 2005;Filaire, Duch, & Lac, 1998). The significant difference in DHEA-S/cortisol ratio (32.7%) between the two groups in our study was strongly aliened with the lower rating in especially the subjective emotional measurement in professional ice-hockey players, that may highlight not only the negative influence of professional and elite sports on performance, but the risk of future ill-health (Endoh, Kristiansen, Casson, Buster, & Hornsby, 1996).
The age-dependence of plasma DHEA-S and its precursor DHEA, and the proposed preventive and anti-aging effects including their role as biomarkers of physiological aging has been debated and questioned (Kroboth, Salek, Pittenge, Fabian, & Frye, 1999;Shimizu, Imanishi, Sugimoto, Takeda, Hirata, Andou, Morikawa, Suzuki, Watanabe, Okuta, Kawana, Namikawa, Suzuki, Watanabe, Okada, & Oht, 2011). Studies have shown that stress and serious disease are associated with a shift from secretion of androgens towards glucocorticoids (Cook-Greuter, 2000). This can mainly be seen as increased plasma cortisol and lower DHEA-S (Corrigan, 2002).
Additionally, a decrease in the DHEA/cortisol ratio and low DHEA-S has been correlated with the suppression of cellular immunity and the severity of disease (Parker & Odell, 1980). The average age-dependent decline in plasma DHEA-S concentrations differed significantly by a few % per year by sex and age group (Baulieu, 1996;Wisniewski, Hilton, Morse, & Svec, 1993;Nafziger, Bowlin, Jenkins, & Pearson, 1998). The falling concentration in DHEA-S related to level of mental and physiological stress and physical illness (Boudarene, Legros, & Timsit-Berthier, 2002) support the hypothesis that those subjects with lower DHEA-S has a shorter life-span (Baulieu, 1996).
A common belief with so far limited support by research, is that elite athletes especially elite players in team sports, have a shorter life span than other human beings (Ruiz, Moran, Arenas, & Lucia, 2010). The thrifty of longevity research show conflicting results, where long-distance runners and cross-country skiers (Kujala, Tikkanen, Sarna, Pukkala, Kaprio, & Koskenvou, 2001;Kujala, 2005) and Tour de France cyclists (Sanchis-Gomar, Olaso-Gonzales, Corella, Gomez-Cabrera, & Vina, 2011) had increased longevity, while individuals with weekly energy expenditure in the range of 3500 kcal show a mortality rate higher than the sedentary population (Paffenbarger, Hyde, Wing, & Hsieh, 1986). A less effective energy expenditure gains a stress induced anabolic hormonal response with increased leptin values in over-strain athletes (Bobbert, Mai, Brechtel, Schult, Weger, Pfeiffer, Spranger, & Diederich, 2012r), a plausible longevity risk factor.

Conclusion
In conclusion our findings indicate that the lower DHEA-S level and DHEA-S/Cortisol ratio among the professional elite players correspond to a biological age around 10 years older than the amateur players. In addition to that the amateur ice hockey players rated themselves as more confident, goal-orientated, motivated and optimistic and with more positive moods and feelings than the professionals. Whether these experiential differences are a result mainly from the training levels or hormonal differences should be investigated in future research.
Other proposals for further research besides doing similar investigations as ours in other sport, (team-and individualsports) could be to investigate the longevity of athletes in different sports and from different levels of physical activity and psychological distress.