Dose-response relationship of cardiorespiratory fitness adaptation to controlled endurance training in sedentary older adults

Eur J Prev Cardiol. 2016 Mar;23(5):518-29. doi: 10.1177/2047487315582322. Epub 2015 Apr 21.


Background: The purpose of this investigation was to identify a quantitative dose-response relationship for enhancing maximal oxygen consumption (VO2max) in healthy sedentary older adults after controlled endurance training.

Methods and results: This meta-analysis of controlled clinical trials included 1257 exercisers and 845 controls with a mean age of 67.45 ± 5.25 years. Effect sizes were calculated for training-induced VO2max changes. Different training regimens were analyzed and compared. The weighted net change of the mean VO2max values showed a significant increase of 3.78 ml/kg per min (95% confidence interval = 3.29 to 4.27; p < 0.0001) in response to aerobic training. Interstudy differences in VO2max changes were significantly related to exercise intensity, and explained approximately 11% of the variance of the VO2max responses. VO2max improved significantly at 35%-50% heart rate reserve (HRR) and continued improving at a greater rate with increasing "dose". The largest VO2max-improvement adaptation was achieved with a mean intensity of 66%-73% HRR. The magnitudes of the VO2max adaptation are identical to exercise at 57%-65% HRR and at 75%-80% HRR. Higher intensity doses more than 75-80% HRR did not lead to greater enhancement of VO2max improvements but, conversely, resulted in large declines.

Conclusions: Our data provide quantitative insight into the magnitude of VO2max alterations as affected by exercise intensity, duration, frequency, and program length. The shapes of the dose-response curves are not simply linear, but with many similar trends and noteworthy characteristics. Aerobic training at a mean intensity of 66%-73% HRR with 40-50 min per session for 3-4 day/week for 30-40 weeks appears to be effective and optimal for maximum cardiorespiratory benefits in healthy sedentary older adults.

Keywords: Controlled clinical trials; VO2max; aerobic exercise; aerobic fitness; aging; elderly; intensity; meta-analysis; optimal prescription; sedentary.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Controlled Clinical Trials as Topic
  • Exercise Therapy / methods*
  • Exercise Tolerance
  • Female
  • Health Status
  • Humans
  • Male
  • Middle Aged
  • Oxygen Consumption*
  • Physical Endurance*
  • Physical Fitness
  • Sedentary Behavior*
  • Time Factors
  • Treatment Outcome