TY - JOUR
T1 - Time-Efficient, High-Resistance Inspiratory Muscle Strength Training Increases Exercise Tolerance in Midlife and Older Adults
AU - Craighead, Daniel H.
AU - Freeberg, Kaitlin A.
AU - Heinbockel, Thomas C.
AU - Rossman, Matthew J.
AU - Jackman, Rachel A.
AU - McCarty, Narissa P.
AU - Jankowski, Lindsey R.
AU - Nemkov, Travis
AU - Reisz, Julie A.
AU - D’Alessandro, Angelo
AU - Chonchol, Michel
AU - Bailey, E. Fiona
AU - Seals, Douglas R.
N1 - Publisher Copyright:
Copyright © 2023 by the American College of Sports Medicine.
PY - 2024/2/1
Y1 - 2024/2/1
N2 - Purpose: This study aimed to determine if time-efficient, high-resistance inspiratory muscle strength training (IMST), comprising 30 inhalation-resisted breaths per day, improves cardiorespiratory fitness, exercise tolerance, physical function, and/or regional body composition in healthy midlife and older adults. Methods: We performed a double-blind, randomized, sham-controlled clinical trial (NCT03266510) testing 6 wk of IMST (30 breaths per day, 6 d·wk−1, 55%–75% maximal inspiratory pressure) versus low-resistance sham training (15% maximal inspiratory pressure) in healthy men and women 50–79 yr old. Subjects performed a graded treadmill exercise test to exhaustion, physical performance battery (e.g., handgrip strength, leg press), and body composition testing (dual x-ray absorptiometry) at baseline and after 6 wk of training. Results: Thirty-five participants (17 women, 18 men) completed high-resistance IMST (n = 17) or sham training (n = 18). Cardiorespiratory fitness (VO 2peak) was unchanged, but exercise tolerance, measured as treadmill exercise time during a graded exercise treadmill test, increased with IMST (baseline, 539 ± 42 s; end intervention, 606 ± 42 s; P = 0.01) but not sham training (baseline, 562 ± 39 s; end intervention, 553 ± 38 s; P = 0.69). IMST increased peak RER (baseline, 1.09 ± 0.02; end intervention, 1.13 ± 0.02; P = 0.012), peak ventilatory efficiency (baseline, 25.2 ± 0.8; end intervention, 24.6 ± 0.8; P = 0.036), and improved submaximal exercise economy (baseline, 23.5 ± 1.1 mL·kg−1min−1; end intervention, 22.1 ± 1.1 mL·kg−1min−1; P < 0.001); none of these factors were altered by sham training (all P > 0.05). Changes in plasma acylcarnitines (targeted metabolomics analysis) were consistently positively correlated with changes in exercise tolerance after IMST but not sham training. IMST was associated with regional increases in thorax lean mass (+4.4%, P = 0.06) and reductions in trunk fat mass (−4.8%, P = 0.04); however, peripheral muscle strength, muscle power, dexterity, and mobility were unchanged. Conclusions: These data suggest that high-resistance IMST is an effective, time-efficient lifestyle intervention for improving exercise tolerance in healthy midlife and older adults.
AB - Purpose: This study aimed to determine if time-efficient, high-resistance inspiratory muscle strength training (IMST), comprising 30 inhalation-resisted breaths per day, improves cardiorespiratory fitness, exercise tolerance, physical function, and/or regional body composition in healthy midlife and older adults. Methods: We performed a double-blind, randomized, sham-controlled clinical trial (NCT03266510) testing 6 wk of IMST (30 breaths per day, 6 d·wk−1, 55%–75% maximal inspiratory pressure) versus low-resistance sham training (15% maximal inspiratory pressure) in healthy men and women 50–79 yr old. Subjects performed a graded treadmill exercise test to exhaustion, physical performance battery (e.g., handgrip strength, leg press), and body composition testing (dual x-ray absorptiometry) at baseline and after 6 wk of training. Results: Thirty-five participants (17 women, 18 men) completed high-resistance IMST (n = 17) or sham training (n = 18). Cardiorespiratory fitness (VO 2peak) was unchanged, but exercise tolerance, measured as treadmill exercise time during a graded exercise treadmill test, increased with IMST (baseline, 539 ± 42 s; end intervention, 606 ± 42 s; P = 0.01) but not sham training (baseline, 562 ± 39 s; end intervention, 553 ± 38 s; P = 0.69). IMST increased peak RER (baseline, 1.09 ± 0.02; end intervention, 1.13 ± 0.02; P = 0.012), peak ventilatory efficiency (baseline, 25.2 ± 0.8; end intervention, 24.6 ± 0.8; P = 0.036), and improved submaximal exercise economy (baseline, 23.5 ± 1.1 mL·kg−1min−1; end intervention, 22.1 ± 1.1 mL·kg−1min−1; P < 0.001); none of these factors were altered by sham training (all P > 0.05). Changes in plasma acylcarnitines (targeted metabolomics analysis) were consistently positively correlated with changes in exercise tolerance after IMST but not sham training. IMST was associated with regional increases in thorax lean mass (+4.4%, P = 0.06) and reductions in trunk fat mass (−4.8%, P = 0.04); however, peripheral muscle strength, muscle power, dexterity, and mobility were unchanged. Conclusions: These data suggest that high-resistance IMST is an effective, time-efficient lifestyle intervention for improving exercise tolerance in healthy midlife and older adults.
KW - ACYLCARNITINES
KW - BODY COMPOSITION
KW - CARDIORESPIRATORY FITNESS
KW - PHYSICAL FUNCTION
UR - http://www.scopus.com/inward/record.url?scp=85182348896&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85182348896&partnerID=8YFLogxK
U2 - 10.1249/mss.0000000000003291
DO - 10.1249/mss.0000000000003291
M3 - Article
C2 - 37707508
AN - SCOPUS:85182348896
SN - 0195-9131
VL - 56
SP - 266
EP - 276
JO - Medicine and science in sports and exercise
JF - Medicine and science in sports and exercise
IS - 2
ER -