The Influence of Acute Resistance and Aerobic Exercise Order on Arterial Stiffness

Aerobic endurance exercise has been repeatedly shown to reduce arterial stiffness, while resistance training can increase arterial stiffness. PURPOSE: To determine whether acute cardiovascular responses are different when performing a resistance training then endurance training (RE) session vs. an endurance training then resistance training (ER) session. We hypothesized that post-exercise aortic systolic blood pressure (SBP), aortic augmentation index normalized to 75 beats per minute (AIx75), and central pulse wave velocity (cPWV) would be lower following RE than ER. METHODS: Non-invasive estimates of aortic SBP, AIx75, and cPWV were measured via applanation tonometry in 8 active adults (6 men; 2 women) before, between, immediately after, and 30 minutes after RE and ER. RE and ER were performed in a random order with about 1 week between testing sessions. Training sessions consisted of approximately 30 minutes of resistance training (6 exercises; 3 sets of 10 for each) and 30 minutes of endurance training (treadmill running). Data were analyzed using a repeated measures ANOVA with 4 times (pre, mid, post 0, and post 30) and 2 modes (RE and ER). RESULTS: Baseline (i.e. pre-exercise) aortic SBP (96±3 vs. 97±3mmHg; p=0.53), AIx75 (-12±4 vs. -16±5%; p=0.22), and cPWV (6.4±0.5 vs. 5.8±0.3 m/s; p=0.29) were similar prior to RE and ER respectively. Aortic SBP was significantly elevated at the end of each exercise bout independent of order (time x mode p=0.13), and returned to baseline values at 30 minutes post-exercise. Likewise, AIx75 increased during RE and ER (time p<0.01) independent of order (time x mode p=0.64), and 30 minute post-exercise values were similar to baseline. Changes in AIx75 (Δ8±6%) from baseline to between modes of exercise during RE were not significant, but changes from baseline to post RE were significant (Δ15±3%; p<0.01). The change in AIx75 (Δ14±4%; p<0.01) from baseline to between modes of exercise during ER and from baseline to post ER were significant (Δ13±4%; p<0.02). Finally, exercise order did not appear to influence cPWV responses (time x mode p=0.21). CONCLUSION: Exercise order did not appear to directly influence acute aortic SBP, AIx75, or cPWV responses. This project was funded in part by a Research Excellence Fund Seed Grant from Michigan Technological University to John Durocher.