Skip Navigation LinksHome > April 2007 - Volume 39 - Issue 4 > Effect of Free-Living Daily Physical Activity on Salivary Se...
Medicine & Science in Sports & Exercise:
doi: 10.1249/mss.0b013e318031306d
CLINICAL SCIENCES: Clinically Relevant

Effect of Free-Living Daily Physical Activity on Salivary Secretory IgA in Elderly


Collapse Box


Purpose: The aim of this work was to assess the relationship in elderly subjects between free-living daily physical activity and mucosal immunity, especially salivary secretory immunoglobulin A (SIgA).

Methods: Elderly volunteers (114 men and 170 women) aged 71.3 ± 0.3 yr (range: 65-86 yr) participated in this study. Resting saliva samples were collected in the morning. Saliva samples stimulated by chewing a sterile cotton ball at a frequency of 60/60 s were collected. The SIgA concentration was measured using enzyme-linked immunosorbent assay (ELISA), and the SIgA secretion rate was calculated. Free-living step count (steps per day), energy expenditure (kJ·kg−1·d−1), and activity durations (min·d−1) at specific intensity levels (inactive, light, moderate, and vigorous) were evaluated using an electric pedometer. The data obtained were stratified by pedometer-determined steps per day using quartiles (Q1-Q4) for distribution.

Results: Elderly in quartiles showed step counts of 2962 ± 94, 5118 ± 62, 6832 ± 59, and 9951 ± 264 steps per day. Significant differences were found in the mean step count (P < 0.0001), energy expenditure (P < 0.0001), and activity duration (P < 0.0001) with increasing pedometer-determined activity quartiles. Both SIgA concentration and SIgA-secretion rate were significantly higher for Q3 than for Q1 (P < 0.05). Meanwhile, saliva flow rates showed no significant differences across quartiles.

Conclusion: These results suggest that a free-living daily physical activity level of approximately 7000 steps per day might be regarded as a moderate daily physical activity target for elderly people to improve mucosal immune function.

©2007The American College of Sports Medicine


Article Tools


Article Level Metrics

Search for Similar Articles
You may search for similar articles that contain these same keywords or you may modify the keyword list to augment your search.

Connect With Us