Immune cell changes in response to a swimming training session during a 24 h recovery period
José Pedro Morgado Applied Physiology, Nutrition, and Metabolism 07 January 2016.
Understanding the impact of training sessions on the immune response is crucial for the adequate periodization of training, in order to prevent both the negative influence on health and the performance impairment of the athlete.
This study evaluated the acute systemic immune cell changes in response to an actual swimming session during a 24 h recovery period, controlling for sex, menstrual cycle phases, maturity, and swimming age groups.
Competitive swimmers (30 females; 15 ± 1.3 yrs., and 35 males; 16.5 ± 2.1 yrs.) performed a high intensity training session. Blood samples were collected before (Pre), immediately after (Post), 2 h after (Post 2h) and 24 h after (Post 24h) exercise. Subjects were grouped according to competitive age groups and pubertal Tanner stages. Menstrual cycle phase was monitored.
The training session induced neutrophilia, lymphopenia and low eosinophils count, lasting for at least 2 h, independently of sex and maturity. At Post 24h, the acquired immunity, expressed by total lymphocytes and total T lymphocytes (CD3+), of juniors (15 – 17 yrs.) was not fully recovered. This should be accounted for when planning the weekly training program. The observed lymphopenia suggests a lower immune surveillance at the end of the session that may depress immunity of athletes, highlighting the need of extra care when exposed to aggressive environmental agents, such as swimming pools.