Introduction:

High blood pressure has a high prevalence and is an important risk factor for the development of cardiovascular diseases, which mostly affect the elderly (PM). As a therapeutic strategy, the isometric hand grip strength training has demonstrated effective results in the hypotensive response. However, the physiological behavior of muscle oxygenation during and after exercise remains unspecified.

Objective:

Analyze the effects of an isometric training protocol for hand grip strength of ascending intensity compared to an isometric training protocol for hand grip strength at 30% of the maximum voluntary contraction on blood pressure and muscle oxygenation kinetics in hypertensive elderly people type1.

Materials and methods:

Quasi-experimental study with a control group in 50 physically active elderly people (men 20 and 30 women) pharmacologically controlled type 1 hypertensive, belonging to the YMCA Santiago, average age 69.6 (± 1.18). Intentional, non-probabilistic and random sampling, considering inclusion and exclusion criteria. An ascending intensity training (10%, 20%, 30% of the maximum voluntary contraction CMV) of hand grip strength was performed for 4 weeks, on an experimental group (GE; n: 25), contrasted with an isometric training (30% CMV) control group (GC; n: 25). The following hemodynamic and anthropometric variables were assessed: heart rate (HR), blood pressure (BP), muscle oxygenation (OM%), weight, height and body mass index (BMI), analyzing the changes before and after training.

Results:

Statistical analysis was performed using the Mann-Whitney U test. In both groups after the intervention, systolic blood pressure (SBP) decreased significantly (GC: 123.6 ± 2.42 to 114.6 ± 2.36 p = 0.01 and GE: 128.1 ± 1, 56 to 111.4 ± 2.31 p <0.000 mmHg) and FC (70.84 ± 1.92 to 64.08 ± 1.87 p = 0.01 and 69.72 ± 2.01 to 64 ± 1.98 p = 0.04 bpm) respectively. The greatest change in muscle oxygenation (OM) is observed only in the GE (57.68 ± 1.34 to 64.56 ± 1.05 p = 0.00 OM%).

Conclusion:

Isometric training protocol for hand grip strength of ascending intensity is a valuable and better tolerated method in older people to decrease BP and improve the percentage of post-exercise muscle oxygenation. Regarding the use of Moxy near infrared spectroscopy (NIRS) sensors, they could play an important role in improving scientific knowledge regarding oxidative muscle metabolism. However, future evaluations are required to determine baseline muscle oxygenation limits.