Maximal fitness testing in sedentary elderly at substantial risk of disability: LIFE-P study experience

Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA, USA.
Journal of aging and physical activity (Impact Factor: 1.97). 11/2008; 16(4):408-15.
Source: PubMed


The authors sought to evaluate the acceptability and feasibility of maximal fitness testing in sedentary older individuals at risk for mobility disability.
Maximal cycle-ergometer testing was performed at baseline and 6 and 12 months later in a subset of LIFE-P study participants at the Cooper Institute site. The mean age of the 20 participants (80% female) tested was 74.7 +/- 3.4 years. The following criteria were used to determine whether participants achieved maximal effort: respiratory-exchange ratio (RER) >1.1, heart rate within 10 beats/min of the maximal level predicted by age, and rating of perceived exertion (RPE) >17.
Participants' mean peak VO2 was 12.1 (3.7) mL . kg-1 . min-1. At baseline testing, only 20% of participants attained an RER >1.10, only 35% achieved a peak heart rate within 10 beats of their age-predicted maximum, and 18% had an RPE of >17. Subsequent testing at 6 and 12 months produced similar results.
In this pilot study of sedentary older persons at risk for mobility disability, very few participants were able to achieve maximal effort during graded cycle-ergometer testing.

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Available from: Thomas Gill, Apr 21, 2015
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    • "It is noteworthy that for all patients VO 2peak and HR peak were achieved at the same 10-s interval. The Borg CR-10 perceived exertion scale was used to estimate the degree of exertion every minute (Borg, 1998). Subjects were verbally encouraged to exercise to volitional fatigue. "
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    • "However, this criterion is not straight forward to use in practical settings [2]. Therefore, a large variety of other end criteria have been used, such as an elevated respiratory exchange ratio (RER) ≥1.0 [3]–[5], 1.10 [6], [7], or 1.15 [8], [9], the achievement of a certain percentage of the age-adjusted estimate of HRmax [7], [10], [11], high postexercise blood lactate levels (≥8 mmol•L–1) [8], [12], the subject's rating of perceived exertion (Borg Scale rating or Visual Analog Scale) [13], or a combination of the above mentioned variables [14]. Thus, there is currently no consensus regarding the assessment of maximal effort during a continuous graded exercise test on the treadmill – especially among women and the elderly – and the knowledge about how different end criteria variables are affected by gender and aging is scarce. "
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    • "Substantial declines in the ability to tolerate physical exertion generally predict mobility problems and cardiovascular morbidity and mortality, particularly in the sedentary elderly [3] [4]. Despite the importance of CRF assessment , very low functional capacity and frailty may hinder the use of exercise tests in this population [5] [6]. In this context , nonexercise prediction models become practical alternatives to estimate CRF [7] and may have important applications both in clinical and epidemiological settings. "
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