Biomechanics and Medicine in Swimming XI

BiomechanicsandmedicineinswimmingXi
ered the most responsive of the inate immune system, being cytotoxic
and producing cytokines against target cells. Our data shows that the
count and the percentage of NK cells tend to exhibit a decrease in the
total NK population In addition the significant alterations observed in
NK cell subsets, with the NKCD56dim subpopulation showing reduced
cell numbers, could represent an impairment of cytotoxic activity with
consequences in immune function. The elevation of the NKCD56bright
/NKCD56dim ratio has been associated with a fall in cytotoxicity activity
(Susui et al. 2004).
In this study no significant alterations in B lymphocyte (CD19+)
cell counts and percentage were observed which is in accordance to previous
published papers (Gleesson et al. 1995).
conclusIon
The presented data confirm that alterations in the immune system may
occur during training periods. The real meaning of this response behaviour,
immune depression or adaptation process is still inconclusive.
The main findings of this study point to an impact on immune
function of progressive and light training loads at the initial phase of
preparation, after long periods of rest, which should be taken into account
by the coaches when adopting recovery strategies aimed at reducing
the negative impact of training. The results also stress the importance
of the use of daily logs or other strategies to monitor how
athletes are adapting to workload, which could be useful in detecting
early signs of difficulties in this process. For example, preventive measures
like nutritional supplementation or training load adjustment could
be implemented. Also important is the medical care support at times of
intensified training load, allowing for a rapid diagnosis and treatment of
the episodes of illness recorded.
In his study we did not look at the immune cells function, so there
is always the possibility that the alterations observed could be related
to blood redistribution factors. However the prevalence of URTIS observed
seems to reflect a real negative impact on immune function and
to the importance of monitoring the effects of training load in athletes.
reFerences
Bonifazi, M., Sardella, F. & Lupo, C. (2000). Preparatory versus main
competitions: differences in performances lactate responses and precompetition
plasma cortisol concentrations in elite male swimmers.
European Journal of Applied Physiology, 82(5-6), 368-373.
Cooper, M. A., Fehniger, T. A. & Caligiuri, M. A. (2001). The biology
of human natural killer-cell subsets. Trends Immunol, 22(11), 633-640.
Costill, D., Maglischo, E. & Richardson, A. (1992). Swimming. Handbook
of Sports Medecine and Science: Blackwell Scientific Publications.
Cox, A. J., Gleeson, M., Pyne, D. B., Saunders, P. U., Clancy, R. L. &
Fricker, P. A. (2004). ValtrexTM Therapy for Epstein-Barr Virus Reactivation
and Upper Respiratory Symptoms in Elite Runners. Med.
Sci. Sports Exerc., 36(7), 1104-1110.
Gleeson, M. (2006). Imune Function in Sport and Exercise (1ª ed.).
Churchill Livingstone Elsevier.
Gleeson, M. (2007). Immune function in sport and exercise. J Appl Physiol,
103(2), 693-699.
Gleeson, M., McDonald, W., Cripps, A., Pyne, D., Clancy, R. & Fricker,
P. (1995). The effect on immunity of long-term intensive training in
elite swimmers. Clin Exp Immunol, 102(1), 210-216.
Heath, G. W., Macera, C. A. & Nieman, D. C. (1992). Exercise and upper
respiratory tract infection: is there a relationship? Sports medicine,
14(6), 353-365.
Mackinnon, L. (2000). Chronic Exercise Training Effects on Immune
Function. Med Sci Sports Exerc., 32(7), S369-S376.
Maglischo, E. (2003). Swimming Fastest. The essential reference on technique,
training, and program design. Human Kinetics, Champaign.
Nagatomi, R. (2006). The implication of alterations in leukocyte subset
counts on immune function. Exerc Immunol Rev, 12, 54-71.
Shinkai, S., Watanabe, S., Asai, H. & Shek, P. N. (1996). Cortisol re-
376
sponse to exercise and post-exercise suppression of blood lymphocyte
subset counts. Int J Sports Med, 17(8), 597-603.
Spence, L., Brown, W. J., Pyne, D. B., Nissen, M. D., Sloots, T. P. & Mc-
Cormack, J. G., et al. (2007). Incidence, Etiology, and Symptomatology
of Upper Respiratory Illness in Elite Athletes. Medicine & Science
in Sports & Exercise, 39(4), 577-586
Suzui, M., Kawai, T., Kimura, H., Takeda, K., Yagita, H. & Okumura,
K., et al. (2004). Natural killer cell lytic activity and CD56dim and
CD56bright cell distributions during and after intensive training. J
Appl Physiol, 96(6), 2167-2173.
Timmons, B. W. & Cieslak, T. (2008). Human natural killer cell subsets
and acute exercise: a brief review. Exerc Immunol Rev, 14, 8-23.
Tyndall, G. L., Kobe, R. W. & Houmard, J. A. (1996). Cortisol, testosterone,
and insulin action during intense swimming training in
humans. Eur J Appl Physiol Occup Physiol, 73(1-2), 61-65.
Urhausen, A., Gabriel, H. & Kindermann, W. (1995). Blood hormones
as markers of training stress and overtraining. Sports Medicine, 20,
251-276.
AcKnoWledGeMents
This project was financed by the Portuguese foundation for Science and
Technology (FCT PTDC/ DES/ 68647/ 2006)