Table II.

Mean adrenal and thymus weights (g per 100 g body weight, ±SEM) for rats from Experiment no. 2 that were exercising (Ex) or sedentary (Sed) for 6 weeks prior to 11 consecutive daily 30 min presentations of 98-dB noise stress, 60-dB background noise, or 10 days of background noise followed by one acute 98-dB noise stress presentation on Day 11 of testing. Only a significant main effect of Activity Status on mean adrenal and thymus weights was found such that, as a function of body weight, adrenals weighed more and the thymus weighed less in Ex as compared to Sed rats (p < 0.05).

Treatment group (n = 8/group for each tissue analyzed)	Mean adrenal weight (g/100 g body weight (SEM))	Mean thymus weight (g/100 g body weight (SEM))
Ex/Acute noise	0.0138 (0.0004)	0.0899 (0.0033)
Ex/Repeated noise	0.0145 (0.0011)	0.0795 (0.0051)
Ex/No noise	0.0143 (0.0004)	0.0839 (0.0082)
Sed/Acute noise	0.0124 (0.0005)	0.0933 (0.0059)
Sed/Repeated noise	0.0129 (0.0006)	0.0981 (0.0077)
Sed/No noise	0.0128 (0.0004)	0.0939 (0.0047)