Wolf C; University of Pittsburgh & San Francisco, CA. USA
Blackwell TL; Johnson E; Glynn NW; Nicklas B; Kritchevsky SB;
Carnero EA; Cawthon PM; Cummings SR; Toledo FGS; Newman AB; Forman DE;
Goodpaster BH

Medicine & Science in Sports & Exercise. 56(9):1574-1584, 2024 Sep 01.

PURPOSE: Cardiorespiratory fitness (CRF) measured by peak oxygen
consumption (VO 2peak ) declines with aging and correlates with mortality
and morbidity. Cardiopulmonary exercise testing (CPET) is the criterion
method to assess CRF, but its feasibility, validity, and reliability in
older adults are unclear. Our objective was to design and implement a
dependable, safe, and reliable CPET protocol in older adults.
METHODS: VO 2peak was measured by CPET, performed using treadmill
exercise in 875 adults >=70 yr in the Study of Muscle, Mobility and Aging
(SOMMA). The protocol included a symptom-limited peak (maximal) exercise
and two submaximal walking speeds. An adjudication process was in place to
review tests for validity if they met any prespecified criteria (VO 2peak
<12.0 mL.kg -1 .min -1 ; maximum heart rate <100 bpm; respiratory exchange
ratio <1.05 and a rating of perceived exertion <15). A subset ( N = 30)
performed a repeat test to assess reproducibility.
RESULTS: CPET was safe and well tolerated, with 95.8% of participants
able to complete the VO 2peak phase of the protocol. Only 56 (6.4%)
participants had a risk alert and only two adverse events occurred: a fall
and atrial fibrillation. Mean +/- SD VO 2peak was 20.2 +/- 4.8 mL.kg -1
.min -1 , peak heart rate 142 +/- 18 bpm, and peak respiratory exchange
ratio 1.14 +/- 0.09. Adjudication was indicated in 47 tests; 20 were
evaluated as valid and 27 as invalid (18 data collection errors, 9 did not
reach VO 2peak ). Reproducibility of VO 2peak was high (intraclass
correlation coefficient = 0.97).
CONCLUSIONS: CPET was feasible, effective, and safe for older adults,
including many with multimorbidity or frailty. These data support a
broader implementation of CPET to provide insight into the role of CRF and
its underlying determinants of aging and age-related conditions.