Article

During senescence, despite the loss of strength (force-generating
capability) associated with sarcopenia, muscle endurance may improve for
isometric contractions.
The purpose of this study was to perform a
systematic meta-analysis of young versus older adults, considering likely
moderators (ie, contraction type, joint, sex, activity level, and task
intensity). DATA SOURCES:
A 2-stage systematic review identified potential
studies from PubMed, CINAHL, PEDro, EBSCOhost: ERIC, EBSCOhost: Sportdiscus, and
The Cochrane Library. STUDY SELECTION: Studies reporting fatigue tasks (voluntary
activation) performed at a relative intensity in both young (18-45 years of age)
and old (>/= 55 years of age) adults who were healthy were considered. DATA
EXTRACTION: Sample size, mean and variance outcome data (ie, fatigue index or
endurance time), joint, contraction type, task intensity (percentage of maximum),
sex, and activity levels were extracted. DATA SYNTHESIS: Effect sizes were (1)
computed for all data points; (2) subgrouped by contraction type, sex, joint or
muscle group, intensity, or activity level; and (3) further subgrouped between
contraction type and the remaining moderators. Out of 3,457 potential studies, 46
publications (with 78 distinct effect size data points) met all inclusion
criteria. LIMITATIONS: A lack of available data limited subgroup analyses (ie,
sex, intensity, joint), as did a disproportionate spread of data (most
intensities >/= 50% of maximum voluntary contraction). CONCLUSIONS: Overall,
older adults were able to sustain relative-intensity tasks significantly longer
or with less force decay than younger adults (effect size=0.49). However, this
age-related difference was present only for sustained and intermittent isometric
contractions, whereas this age-related advantage was lost for dynamic tasks. When
controlling for contraction type, the additional modifiers played minor roles.
Identifying muscle endurance capabilities in the older adult may provide an
avenue to improve functional capabilities, despite a clearly established decrement in peak torque.

Langue : ANGLAIS