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Mitch D. VanBruggen, Anthony C. Hackney, Robert G. McMurray, and Kristin S. Ondrak

Purpose:

The effect of exercise intensity on the tracking of serum and salivary cortisol responses was examined in 12 endurance-trained males (maximal oxygen uptake [VO2max] = 58.2 ± 6.4 mL/kg/min).

Methods:

Subjects rested for 30 min (control) and exercised on a cycle ergometer for 30 min at 40% (low), 60% (moderate), and 80% (high intensity) of VO2max on separate days. Serum and saliva samples were collected pretrial, immediately posttrial, and 30 min into the recovery period from each trial.

Results:

Cortisol responses increased significantly for both serum (40.4%; P = .001) and saliva (170.6%; P = .007) only in response to high-intensity exercise. Peak saliva cortisol occurred at 30 min of recovery, whereas peak serum was at the immediate posttrial sampling time point. The association between serum and saliva cortisol across all trials was examined using concordance correlation (R c) analysis, which accounts for repeated measures. The overall correlation between serum and saliva cortisol levels in all matched samples was significant (R c = 0.728; P = .001). The scatter plot revealed that salivary cortisol responses tracked closely to those of serum at lower concentrations, but not as well at higher concentrations.

Conclusions:

Findings suggest salivary measurements of cortisol closely mirror those in the serum and that peak salivary concentrations do not occur until at least 30 min into the recovery from intense exercise.

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Mary N. Woessner, Michael A. Welsch, Mitch D. VanBruggen, Neil M. Johannsen, Daniel P. Credeur, Carl F. Pieper, Richard Sloane, Conrad P. Earnest, Joaquin Ortiz De Zevallos Munoz, Timothy S. Church, Eric Ravussin, William E. Kraus, and Jason D. Allen

Exercise training beneficially moderates the effects of vascular aging. This study compared the efficacy of Peripheral Remodeling through Intermittent Muscular Exercise (PRIME), a novel training regimen, versus aerobic training on hemodynamic profiles in participants ≥70 years at risk for losing functional independence. Seventy-five participants (52 females, age: 76 ± 5 years) were assessed for hemodynamic and vascular function at baseline, after 4 weeks of either PRIME or aerobic training (Phase 1) and again after a further 8 weeks of aerobic and resistance training (Phase 2). Data were analyzed using 2 × 2 repeated-measures analysis of variance models on the change in each dependent variable. PRIME demonstrated reductions in brachial and aortic mean arterial pressure and diastolic blood pressure (p < .05) from baseline after Phase 1, which were sustained throughout Phase 2. Earlier and greater reductions in blood pressure following PRIME support the proposal that peripheral muscular training could beneficial for older individuals commencing an exercise program.