Routine Exercise Alters Measures of Immunity and the Acute Phase Reaction

Purpose: To expand our understanding of the overall anti-inflammatory nature of routine exercise; we compared resting blood values from adults who habitually undertake frequent, moderate levels of exercise to reference interval values assumed to reflect values largely from non-exercisers. This information would be useful for clinicians interpreting blood tests assessing inflammatory, immune and acute phase responses.

Methods: Blood samples were collected from 119 community adult self-reported routine exercisers (61 males and 58 females aged 18-60 years). Samples were analysed for 20 cellular and non-cellular biomarkers which included 11 immunological and 9 acute phase reactants. These data were compared to reference intervals from the same hospital laboratory that performed the analyses on our participants' samples. Individual analyte values were also compared with participants' self-reported 150 day exercise patterns which included exercise frequency, intensity and duration.

Results: In general, mean values for routine exercise participants fell at the lower end of laboratory reference interval for most inflammatory analytes. More than 10 % of participants had numbers of CD19(+), CD8(+) and 16/56(+) NK cells below the low end of the respective reference interval. More than 10 % of observed acute phase reactant values (for C3, haptoglobin and ferritin) were also below the low end of the reference interval. At rest IgM (r = -0.22) and IgG (r = -0.31) values correlated negatively (p < 0.05) with exercise load.

Conclusions: Routine exercise appears to lower resting numbers of a variety of immune cell-types as well as the concentration of several classical acute phase reactants. These wide-ranging systemic effects are presumably adaptive changes, not pathology and collectively confirm the well-reported and clinically important anti-inflammatory effects of exercise.