Are fixed-rate step tests medically safe for assessing physical fitness?

Jessa Hospital/Heart Centre Hasselt, Rehabilitation and Health Centre, Stadsomvaart 11, Hasselt, Belgium.
Arbeitsphysiologie (Impact Factor: 2.66). 03/2011; 111(10):2593-9. DOI: 10.1007/s00421-011-1886-3
Source: PubMed

ABSTRACT Maximal oxygen uptake (VO(2max)) can be predicted by fixed-rate step tests. However, it remains to be analyzed as to what exercise intensities are reached during such tests to address medical safety. In this study, we compared the physiological response to a standardized fixed-rate step test with maximal cardiopulmonary exercise testing (CPET). One hundred and thirteen healthy adults executed a maximal CPET on bike, followed by a standardized fixed-rate step test 1 week later. During these tests, heart rate (HR) and VO(2) were monitored continuously. From the maximal CPET, the ventilatory threshold (VT) was calculated. Next, the physiological response between maximal CPET and step testing was compared. The step test intensity was 85 ± 24% CPET VO(2max) and 88 ± 11% CPET HR(max) (VO(2max) and HR(max) were significantly different between CPET and step testing; p < 0.01). In 41% of the subjects, step test exercise intensities >95% CPET VO(2max) were noted. A greater step testing exercise intensity (%CPET VO(2max)) was independently related to higher body mass index, and lower body height, exercise capacity (p < 0.05). Standardized fixed-rate step tests elicit vigorous exercise intensities, especially in small, obese, and/or physically deconditioned subjects. Medical supervision might therefore be required during these tests.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Obesity is one of the greatest public health challenges of the 21st century. Overweight and obesity drastically increase a person's risk of developing chronic non-communicable diseases (NCDs), including cardiovascular disease, can-cer and diabetes. Furthermore, obesity is al-ready responsible for 2% -8% of health costs and 10% -13% of deaths in several industrial-ized countries. Lifestyle modifications involving changes in exercise, diet and psychological support are effective in reducing the incidence of overweight. Moreover, positive effects of physical activity (PA) for weight loss and pre-vention of weight regain are well documented. It was recognized that health benefits regarding both psychological and physiological aspects, such as improving cardiorespiratory and mus-cular fitness and/or decreasing depression symptoms, can be obtained from numerous ac-tivities. Public health institutions (American College of Sports Medicine, World Health Or-ganization) provide recommendations for PA (volume, frequency, intensity and type of exer-cise) to achieve positive effects, at all ages and for many diseases and disorders situations. Al-though exercise under guidelines can be safely performed by obese subjects, several questions still need to be fully answered. In facts, the ex-ercise program should be tailored according to an individual's habitual physical activity, physi-cal function, health status, exercise responses, and stated goals. Thus, this review analyzes the intensity of PA parameters. In the last years, re-search has been focused on the individualiza-tion of the right intensity in which different types of subjects' condition must undergo to achieve the health goals. Aerobic exercise has been commonly used to reach weight loss goal. Pre-scription of aerobic exercise in clinical practice is frequently based on the percentage of maxi-mum heart rate (%HR max), heart rate reserve (%HR reserve), rating of perceived exertion (RPE), maximal oxygen consumption (%VO 2max) and for unhealthy subjects, peak oxygen consumption (%VO 2peak). It has been shown that unhealthy subjects, such as individuals affected by diabe-tes, obesity and cardiovascular diseases have a reduced maximal aerobic exercise capacity. For instance, using the formula based on percent-age of HR max or VO 2max , it could be prescribed heavy exercises, which would result not appro-priated and fully functional for the specific indi-vidual goal. To avoid this problem, another ap-proach to individualize aerobic exercise could be to consider the gas exchange parameters such us aerobic gas exchange threshold (AerT GE). AerT GE corresponds to the first in-crease in blood lactate during incremental exer-cise. This review offers an overview of the dif-ferent methods to assess exercise intensity, considering the different subjects health char-acteristics, in order to choose the right methods to achieve the health goals in obese and over-weight subjects.
    Health 01/2013; 5:113-12156. · 2.10 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Cardiovascular disease is a major cause of mortality and morbidity and its prevalence is set to increase. While the benefits of medical and lifestyle interventions are established, the effectiveness of interventions which seek to improve the way preventive care is delivered in general practice is less so. The aim was to study and to compare the effectiveness of 2 intervention programmes for reducing cardiovascular risk factors within general practice. METHODS: A randomised controlled trial was conducted in Belgium between 2007-2010 with 314 highly educated and mainly healthy professionals allocated to a medical (MP) or a medical + lifestyle (MLP) program. The MP consisted of medical assessments (screening and follow-up) and the MLP added a tailored lifestyle change programme (web-based and individual coaching) to the MP. Primary outcomes were total cholesterol, blood pressure, and body mass index (BMI). The secondary outcomes were smoking status, fitness-score, and total cardiovascular risk. RESULTS: The mean age was 41 years, 95 (32%) participants were female, 7 had a personal cardiovascular event in their medical history and 3 had diabetes. There were no significant differences found between MP and MLP in primary or secondary outcomes. In both study conditions decreases of cholesterol, systolic blood pressure, and diastolic blood pressure were found. Unfavourable increases were found for BMI (p < .05). A significant decrease of the overall cardiovascular risk was reported (p < .001). CONCLUSIONS: Both interventions are effective in reducing cardiovascular risk. In our population the combined medical and lifestyle programme was not superior to the medical program.Trial Registration: ISRCTN23940498.
    BMC Cardiovascular Disorders 06/2013; 13(1):38. · 1.46 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this study was to determine the validity of a submaximal exercise test, the Step Test Exercise Prescription (STEP), in a broad age range and in individuals in the earliest stages of Alzheimer's disease (AD). Individuals (n = 102) underwent treadmill-based maximal exercise testing and a STEP. The STEP failed to predict peak oxygen consumption (VO2 peak), and was a biased estimate of VO2 peak (p < .0001). Only 43% of subjects' STEP results were within 3.5 ml x kg-1 x min-1 of VO2 peak. When categorized into fitness levels these two measures demonstrated moderate agreement (kappa = .59). The validity of the STEP was not supported in our participants, including those with AD. The STEP may not be appropriate in the clinic as a basis for exercise recommendations in these groups, though it may continue to have utility classifying fitness in research or community health screenings.
    Journal of Aging and Physical Activity 12/2012;

Full-text (3 Sources)

Available from
Jun 2, 2014