Respiratory muscle endurance training improves exercise performance but does not affect resting blood pressure and sleep in healthy active elderly

Abstract

Purpose: Ageing is associated with increased blood pressure (BP), reduced sleep, decreased pulmonary function and exercise capacity. The main purpose of this study was to test whether respiratory muscle endurance training (RMET) improves these parameters.

Methods: Twenty-four active normotensive and prehypertensive participants (age: 65.8 years) were randomized and balanced to receive either RMET (N = 12) or placebo (PLA, N = 12). RMET consisted of 30 min of volitional normocapnic hyperpnea at 60% of maximal voluntary ventilation while PLA consisted of 1 inhalation day^-1 of a lactose powder. Both interventions were performed on 4-5 days week^-1 for 4-5 weeks. Before and after the intervention, resting BP, pulmonary function, time to exhaustion in an incremental respiratory muscle test (incRMET), an incremental treadmill test (IT) and in a constant-load treadmill test (CLT) at 80% of peak oxygen consumption, balance, sleep at home, and body composition were assessed. Data was analyzed with 2 × 2 mixed ANOVAs.

Results: Compared to PLA, there was no change in resting BP (independent of initial resting BP), pulmonary function, IT performance, sleep, body composition or balance (all p > 0.05). Performance significantly increased in the incRMET (+ 6.3 min) and the CLT (+ 3.2 min), resulting in significant interaction effects (p < 0.05).

Conclusion: In the elderly population, RMET might be used to improve respiratory and whole body endurance performance either as an adjunct to physical exercise training or as a replacement thereof for people not being able to intensively exercise even if no change in BP or sleep may be expected.

Keywords: Blood pressure; Exercise performance; Hyperpnea; Hypertension; Lung function; Sleep efficiency.

Fig. 1

Systolic and diastolic blood pressure before and after respiratory muscle endurance training (RMET) and placebo inhalations (PLA). Grey lines show individual data and black lines give group means. SBP systolic blood pressure, DBP diastolic blood pressure

Fig. 2

Time to exhaustion during the constant load treadmill test (CLT) before and after respiratory muscle endurance training (RMET) and placebo inhalations (PLA). Grey lines show individual data and black lines give group the mean. **p < 0.01, within group comparison, paired t test; ^#p < 0.05, mixed ANOVA, interaction effect

Fig. 3

Relationship between constant load test (CLT) performance and respiratory exertion. Left relative change (post vs. pre) in time to exhaustion (TTE) vs. change in respiratory effort (RE) averaged until isotime. Right relative change (post vs. pre) in TTE vs ratio RE and leg exertion (LE) at the end of the CLT performed on the 2nd visit (pre). RMET respiratory muscle endurance training, PLA placebo