Cardiac Rehabilitation Combined Training Improves Lower Limb Strength After 12 Sessions In Elderly Patients

Abstract

Increased quadriceps muscle strength has shown to decrease the risk of cardiovascular mortality by 34% in patients with coronary heart disease. Muscle mass and strength declines progressively in the elderly and training effects have been generally reported after 12 weeks. Adherence to cardiac rehabilitation programs is usually low, with less than 50% of patients completing 36 sessions in 12 weeks. There is still no consistent evidence that muscle strength in elderly patients can be improved after just 12 sessions of cardiac rehabilitation. PURPOSE: To evaluate the effect of 12 sessions of combined training on lower limb strength, in elderly patients attending a cardiac rehabilitation program 2-3 times per week. METHODS: Patients included eighty-four elderly (>60 yrs) (21 women, age 67 ± 6 yrs; 63 male, age 70 ± 7 yrs) attending a cardiac rehabilitation program in a university hospital in Bogotá city, Colombia. They were evaluated from January to September 2019 before and after 12 training sessions 2-3 times per week, which included 30 minutes of cardiovascular aerobic and 15 minutes of multifunctional strength training. Aerobic training was performed at 60 - 85% of the estimated maximal heart rate. Progressive resistance strength training included 3 sets of 10-15 repetitions of major muscle groups with 50 - 70% estimated 1-repetition maximum (1-RM) including elastic bands, cuff weights, free weights and gym machines. Baseline and follow up evaluation at the 12th session were performed by a horizontal leg press machine with 1-RM estimation according to Brzycki formula: (1-RM: 100* load repetition / (102.78 - 2.78 *rep). Pre/post training changes were assessed by paired t tests. RESULTS: After 12 training sessions a significant maximum strength increase was found, both for men (189.6 ± 42.6 vs 203.0 ± 47.4; p = 0.000), and women (116.1 ± 18.8 vs 140.6 ± 31.0; p = 0.000). CONCLUSIONS: This study showed that twelve sessions of combined training in elderly patients attending a cardiac rehabilitation program, improved lower limb strength in less time than usually reported. This finding supports the importance and feasibility of including strength in addition to aerobic training to reduce cardiovascular risk in this growing population.