Personalized exercise prescription as a tool for hypertension management and cardiovascular prevention: evidence and pending issues

Are There Interindividual Responses of Cardiovascular Disease Risk Markers to Acute Exercise? A Replicate Crossover Trial

PURPOSE

Using a replicated crossover design, we quantified the response heterogeneity of postprandial cardiovascular disease risk marker responses to acute exercise.

METHODS

Twenty men (mean (SD) age, 26 (6) yr; body mass index, 23.9 (2.4) kg·m -2 ) completed four 2-d conditions (two control, two exercise) in randomized orders. On days 1 and 2, participants rested and consumed two high-fat meals over 9 h. Participants ran for 60 min (61 (7)% of peak oxygen uptake) on day 1 (6.5 to 7.5 h) of both exercise conditions. Time-averaged total area under the curve (TAUC) for triacylglycerol, glucose, and insulin were calculated from 11 venous blood samples on day 2. Arterial stiffness and blood pressure responses were calculated from measurements at baseline on day 1 and at 2.5 h on day 2. Consistency of individual differences was explored by correlating the two replicates of control-adjusted exercise responses for each outcome. Within-participant covariate-adjusted linear mixed models quantified participant-by-condition interactions and individual response SDs.

RESULTS

Acute exercise reduced mean TAUC-triacylglycerol (-0.27 mmol·L -1 ·h; Cohen's d = 0.29, P = 0.017) and TAUC-insulin (-25 pmol·L -1 ·h; Cohen's d = 0.35, P = 0.022) versus control, but led to negligible changes in TAUC-glucose and the vascular outcomes (Cohen's d ≤ 0.36, P ≥ 0.106). Small-to-moderate, but nonsignificant, correlations were observed between the two response replicates ( r = -0.42 to 0.15, P ≥ 0.066). We did not detect any individual response heterogeneity. All participant-by-condition interactions were P ≥ 0.137, and all individual response SDs were small with wide 95% confidence intervals overlapping zero.

CONCLUSIONS

Large trial-to-trial within-subject variability inhibited detection of consistent interindividual variability in postprandial metabolic and vascular responses to acute exercise.

A comparison of two Tai Chi interventions tailored for different health outcomes

OBJECTIVES

We compared the health benefits of two different Tai Chi interventions tailored for improving blood pressure (BP) (PRESSURE) or balance (BALANCE).

DESIGN

randomized controlled trial.

SETTING

Community dwelling older adults (≥60yr) practiced Tai Chi at the fitness center of a continuous care community.

INTERVENTIONS

We tailored PRESSURE to emphasize breathing techniques and mental relaxation and BALANCE to emphasize movement principles that challenged balance. Subjects were randomized to PRESSURE (n = 12), BALANCE (n = 13), or CONTROL (n = 10). Tai Chi was practiced 3 sessions/wk, 60 min/session for 12 wk. CONTROL performed normal daily activities.

MAIN OUTCOME MEASURES

We compared the change in cardiometabolic health, balance, and functional fitness between groups with ANCOVA using baseline values, age, and body mass index as covariates.

RESULTS

Subjects were physically active, Tai Chi naive (97.1 %), white, mostly female (82.9 %), and older (78.9 ± 5.7 yr) with resting systolic BP (SBP) of 126.5 ± 14.4 mmHg and diastolic BP of 69.3 ± 8.4 mmHg. PRESSURE significantly improved Chair Sit-to-Stand Test (CSTS) (1.0 ± 1.8 vs.-0.6 ± 0.8times/30s,p = 0.03) versus CONTROL, and gait speed (12.8±43.3 vs.-24.1±22.4cm/sec, p = 0.02) versus BALANCE. Meanwhile, BALANCE significantly improved Single Leg Stance Test (5.4±18.0 vs.-8.2±10.3 s, p = 0.049) and CSTS (1.0±1.7 vs.-0.6±0.8times/30s, p = 0.03), and tended to lower SBP (-4.2±16.0 vs. 3.5±8.3mmHg, p = 0.052) versus CONTROL.

CONCLUSION

Within 3 months, Tai Chi improved several health outcomes independent of the type of practice among physically active, Tai Chi naive older adults. Therefore, healthcare and exercise professionals may recommend Tai Chi to physically active older adults without specifying the type of practice.