Effects of single and two bouts of intense exercise in the same day on salivary iga and cortisol concentrations in non – atleth Effects of single and two bouts of intense exercise in the same day on salivary iga and cortisol concentrations in non – atleth

Effects of single and two bouts of intense exercise in the same day on salivary iga and cortisol concentrations in non – atleth Effects of single and two bouts of intense exercise in the same day on salivary iga and cortisol concentrations in non – atleth

ABSTRACT

The aim of this study was to observe the relationship between salivary immunoglobulin A (IgA) and cortisol concentrations in response to daily training load in Non – Atleth. 10 young female Non – athletes (age16± 2 years, height162 ± 3.8 cm, weight 45 ± 5.3 kg) engaged in controlled training sessions performed either once per day and twice per day starting at 9:oo a.m. and from 6 p.m. Samples of 5 ml of unstimulated saliva collected pre-exercise, immediately after exercise and 2 hr following exercise session were taken for measurement of salivary IgA and cortisol.

Salivary IgA was not different after one or two sessions of exercise (p > 0.05) were performed, while salivary cortisol was significantly higher when two training sessions were performed on the same day (p 0.05). No significant correlation was observed between IgA and cortisol concentration. The results of this study showed that inceased training load in Non – atleth female has no effect on salivary IgA conentration, but is associated with an increase in cortisol concentration on the heavier workload day.

INTRODUCTION

During the last 20 years the immunological aspect of sport and exercise has been concern of many sport scientists. Data from their laboratories indicate significant interaction between the neural, hormonal and immunologic systems and exercise, both in acute exercise and exercise training (MACKINON, 1999). The correlation between training load and suppression immune defense systems is not fully understood, although the consensus is that light exercise can improve the immune response whilst strenuous exercise can depress the defense system such that an individual is more susceptible to acquiring infection (GLEESON, 2000).

An upper respiratory tract infection (URTI) is a common infection in athletes, particularly after prolonged and heavy exercise. One of the reasons for this increased incidence of URTI could be due to depression of salivary immunoglobulin A (IgA) which acts as main barrier against the colonization of infective agents on the mucosal layer of mouth, nose, intestinal and genital tract (GLEESON, 2000). Fahlman et al. (2000) reported a significant relationship between reduction of salivary IgA and the incidence of URTI after one season of playing football.

Other investigators have shown that significant changes in salivary IgA level during exercise are associated with an increased incidence of URTI in the elite athletes (MACKIONN, 2000 ; RUDOLPH & MC CAULEY, 1998). Increased circulating levels of stress-related hormones (e.g. cortisol) which result from heavy and prolonged aerobic exercise can suppress the immune system and are thus suggested to be a main causes of URTI in athletes (PYNE et al.,2000). Elevation of cortisol level following heavy exercise is associated with a reduction in salivary IgA concentration (RUDOLPH & MC CAULEY, 1998; DIMITRIOU et al., 2002), however the specific relationship appears to be linked to the intensity, duration and type of physical activity (MACKINON, 1999; MACKINON, 1997; MACKINON et al.,1993 ; MACKINON et al.,1994).

Elite swimmers, often with multiple daily training sessions, experience heavy physical and mental stress. Inadequate rest periods may impair recovery and these athletes may then produce an inefficient immunologic response when exposed to an infectious agent (MACKINON et al., 1993; MACKINON et al., 1992).Yet, such research is necessary for both performance and health-related reasons in this often young and vulnerable group. The aim of this study was to: a) determine the effects of training on salivary IgA and cortisol response and, b) determine the correlation between salivary cortisol and IgA concentration after exercise in Npn – atleth female.

METHODS

Subjects

10 Non – atleth female subjects aged16± 2 years, height 162 ± 3.8 cm, weight 45 ± 5.3 kg were recruited for the study. A full verbal and written description of all procedures, risks and requirements of the study was given to all subjects and their parents, and all subjects and their parents or guardians signed a consent form. All subjects were in good health, and were not using medications or supplements known to affect immune function.

Training Protocol

All subjects performed two testing days during routine training. During the first test day, at 18.00 the subjects run 400 meter 10times with maximum rate of speed and with 1:1 minute rest period. One week later, this exercise was done 2bouts in a day. (one bouts at 09.00 and one bout at 18.00).The intensity of exercise was controlled with a record. Saliva collection Three milliliters of unstimulated saliva was collected before exercise session (rest condition), immediately after each session, and 2 hours post-exercise session. To reduce the effect of diurnal variations on hormone concentrations.

Saliva samples were obtained from individual subjects at the same time of day. Before saliva collection, subjects were required to rinse out their mouths for one minute with water to remove any substances such as chlorine that may affect SIgA or cortisol levels. To standardize saliva collection, subjects were seated in comfortable position, with slightly lowered head, allowing spontaneous saliva flow in the mouth. Once collected, saliva samples were immediately placed on ice and within 1 h were frozen (- 20C) until assayed for S-IgA and cortisol.

The concentration of S-IgA was measured by the ELISA. Salivary Cortisol concentrations were measured in duplicate by Enzyme Linked Immunosorbant Assay (ELISA). The kit for cortisol were obtained from RADIM, Pomezia (Italy). All saliva samples were subject to a single freeze thaw cycle to break down mucopolysaccharides that can interfere with pipetting. On the day of assay, samples were centrifuged (1500 × g, 15 min) to remove particulate matter, and clear samples were transferred into appropriate test wells.

STATICAL ANALYSIS

Means and standard deviations were calculated for all variables of interest. One-way analyses of variance with repeated measures and Student LSD-test were used to determine significant differences. To determine the correlation among variables, Pearson correlation coefficients were used. Before these analyses were performed, the frequency distributions were tested for normality using the Kolmogrof-Smirnov test. The level of significance was set at p < 0.05. All analyses were run by SPSS for Windows.

RESULTS

The mean and standard deviation (SD) of salivary IgA and cortisol concentration in pre- and post exercise are shown in Figure 1 (Panel A and B). The level of S-IgA was highest on the first day immediately after exercise when compared to other sampling time points (p < 0.05). Post hoc testing revealed that S-IgA was significantly superior immediately after exercise as compared to other sampling points (p 0.05). In addition, the study did not reveal any significant correlation between S-IgA and cortisol concentrations.

DISCUSSION

Results of the present study indicate that in Non – atleth there is no significant difference in salivary IgA levels as a result of training once or twice per day. Our observations may be explained by the low intensity of exercise, since the increased level of exercise probably inhibits IgA secretion (PYNE et al., 2000: DIMITRIOU et al., 2002; MC DOWELL et al., 1991; REID et al., 2001;) Moreover, level of IgA could be affected by intensity, duration and kind of exercise, age and physical fitness of the subjects and other factors (BLANNIN et al., 1998). Furthermore, biological immaturity of recruited subjects could lead to hormonal disturbances which requires further investigation.

Previous studies indicate involvement of several factors causing changes in IgA levels as follow – the rate of suppression of various hormones such as cortisol, ?- endorphin; physical and mental stress; decline of saliva and low intensity of exercise (GLEESON, 2000; MACKINON et al.,1994). investigations (GLEESON, 2000; MACKINON, 1997). Two sessions of exercise per day was associated wtih increased salivary cortisol concentrations. Postexercise cortisol concentration changes seems to be affected by several mechanisms – stimulation of sympathetic nervous system, stimulation of hypothalamic-pituitary-adrenal (HPA) secretion, increase of body temperature, changes in blood pH, hypoxia, lactate accumulation and mental stress (; FIALIRE et al.,1996; LAC et al., 1997). Kaciaba-Usiko et al. (1992) reported that cortisol concentration increases with increased daily exercise volume. Ben-Aryeh et al.(1989) stated that cortisol concentration increases by continued exercises.

These researchers reported that physical exercise could stimulate HPA, increases body temperature, increases cortisol secretion and release of cortisol from the carrier proteins. Therefore, the high concentration of salivary cortisol accompanied with increase of saliva viscosity, is the indicator of sympathetic nervous system activation (BEN-ARYEH et al.,1989). The findings of this study correspond with findings of Kaciaba-usiko et al. (1992), Rudolph and McCauley (1982) and Ben-Aryeh et al. (1989). Dally and Kelin (1998) reported that decreased volume of exercise does not change the way of adrenal function in gymnasts. Corral et al. (1994) in their study with adolescent boys did not find any significant changes in cortisol concentration 30 minutes after aerobic exercise which is in accordance with Daly and Kelin (1998). Furthermore, results of this study do not support the data given by O’Connor et al. (1991). The equivocal nature of these observations may be due to the difference in intensity, duration and mode of exercise, the place of exercise, and the age of the subjects in each study (O’CONNOR et al.1991).

We found a lack of correlation between IgA and cortisol concentrations. Specifically, we observed that IgA concentration in daily two-session exercise did not change while cortisol concentration changed. Our findings those , reporting that during heavy and moderate exercises cortisol secretion had no relationship with inhibition of salivary IgA. We conclude that IgA level is not influenced by the intensity of exercise, but cortisol concentration seems to be influenced by daily exercise load. No changes in IgA level after two sessions exercise daily indicates that the daily exercise performed by Non – Atleth female may not have be of sufficient load to impair immune defense.