Respiratory muscle endurance training reduces the O₂ cost of cycling and perceived exertion in obese adolescents

Abstract

In obesity, the increased O cost of breathing negatively affects the O cost of exercise and exercise tolerance. The purpose of the study was to determine whether, in obese adolescents, the addition of respiratory muscle endurance training (RMET) (isocapnic hyperpnea) to a standard body mass reduction program decreases the O cost of exercise and perceived exertion. Nine male obese adolescents [16.0 ± 1.4 yr ( ± SD), body mass 114.4 ± 22.3 kg] underwent 3 wk of RMET (5 days/week) in addition to a standard body mass reduction program. Eight age- and sex-matched obese adolescents underwent only the standard program (CTRL). Before and after interventions, patients performed on a cycle ergometer: incremental exercise; 12-min exercises at a constant work rate (CWR) of 65% and 120% at the gas exchange threshold (GET) determined before the intervention. Breath-by-breath pulmonary ventilation (V̇e) and O uptake (V̇o), heart rate (HR), and ratings of perceived exertion for dyspnea/respiratory discomfort (RPE) and leg effort (RPE) were determined. Body mass decreased (by ~3.0 kg) after both RMET ( = 0.003) and CTRL ( = 0.002). Peak V̇o was not affected by both interventions. Peak work rate was slightly, but significantly ( = 0.04), greater after RMET but not after CTRL. During CWR < GET, no changes were observed after both interventions. During CWR > GET, the O cost of cycling at the end of exercise ( = 0.02), the slope of V̇o vs. time (3-12 min) ( = 0.01), RPE ( = 0.01), and RPE ( = 0.01) decreased following RMET, but not following CTRL. HR decreased after both RMET ( = 0.02) and CTRL ( = 0.03), whereas V̇e did not change. In obese adolescents RMET, superimposed on a standard body mass reduction program, lowered the O cost of cycling and perceived exertion during constant heavy-intensity exercise.

Three weeks of respiratory muscle endurance training improve the O2 cost of walking and exercise tolerance in obese adolescents

“…This difference corresponds to the mean difference previously observed following RMET in obese adolescents during cycling (Salvadego et al. ). A two‐way analysis of variance (ANOVA) with repeated measures (2 groups × 2 times) was used to assess changes in anthropometry, spirometry parameters and exercise tolerance in two groups (RMET vs. CTRL) over the protocol period (pre vs. post).…”

“…; Salvadego et al. ). The device consists of a hand‐held unit with a respiratory pouch and a base station.…”

“…The patients were admitted as in‐patients (Division of Auxology, Italian Institute for Auxology, Piancavallo, Italy) for a 3‐week in‐hospital multidisciplinary BM reduction intervention (Salvadego et al. ), involving the following: (1) Moderate energy restriction, with a personalized diet entailing an energy intake ~500 kcal lower than the measured resting energy expenditure. Diet composition was formulated according to the Italian recommended daily allowances (Società Italiana di Nutrizione Umana); the compliance to the diet was monitored daily by a dietician.…”

“…; Salvadego et al. , ). Obesity has indeed a profound effect on the physiology of breathing (Luce ; Koenig ).…”

“…; Salvadego et al. , ). This is exacerbated by the higher pulmonary ventilation at the same work rate observed in obese patients versus normal weight controls (Cherniack ; Kress et al.…”