VO2 Reserve and the Minimal Intensity for Improving Cardiorespiratory Fitness

Purpose: The American College of Sports Medicine has stated that aerobic: training needs to occur at a minimum threshold intensity of 50% VO2max for most healthy adults and at 40% VO2max for those with a very low initial fitness. Recently, the concept of VO2 reserve (% VO2R, i.e., a percentage of the difference between maximum and resting VO2 has been introduced for prescribing exercise intensity, This analysis was designed to determine the threshold intensity for improving cardiorespiratory fitness expressed as %VO2R units. Methods: Previous studies in healthy subjects (N = 18) that evaluated the result, of training at low-to-moderate intensities (i.e., less than or equal to 60% VO2max) were identified. The original studies described the intensity of exercise variously as %VO2max, %HRR, %HRmax or as a specific HR value. In each case, the intensity was translated into %VO2R units. Results: Exercise training intensities below approximately 45% VO2R were consistently ineffective at increasing VO2max in studies that used subjects with mean initial VO2max values \u3e 40 mL.min-1 kg-1. In studies using subjects with mean initial VO2max values \u3c 40 mL.min-1.kg-1, no intensity A as found to be ineffective. For this latter group of subjects, the lowest intensities examined A ere approximately 30% VO2R. Conclusion: Although evidence for a threshold intensity was not strong, this analysis of training studies support the use of 45% VO2R as a minimal effective training intensity for higher fit subjects and 30% VO2R for lower fit subjects

Influence of central obesity in estimating maximal oxygen uptake

OBJECTIVE: To assess the influence of central obesity on the magnitude of the error of estimate of maximal oxygen uptake in maximal cycling exercise testing. METHOD: A total of 1,715 adults (68% men) between 18-91 years of age underwent cardiopulmonary exercise testing using a progressive protocol to volitional fatigue. Subjects were stratified by central obesity into three quartile ranges: Q1, Q2-3 and Q4. Maximal oxygen uptake [mL.(kg.min)-1] was estimated by the attained maximal workload and body weight using gender- and population-specific equations. The error of estimate [mL.(kg.min)-1] and percent error between measured and estimated maximal oxygen uptake values were compared among obesity quartile ranges. RESULTS: The error of estimate and percent error differed (mean ± SD) for men (Q1=1.3±3.7 and 2.0±10.4; Q2-3=0.5±3.1 and -0.5±13.0; and Q4=-0.3±2.8 and -4.5±15.8 (

Effects of Supervised Exercise-based Telerehabilitation on Walk Test Performance and Quality of Life in Patients in India with Chronic Disease: Combatting COVID-19

Background: The world is currently undergoing a pandemic, caused by the SARS-CoV-2 virus (COVID-19). According to the World Health Organization, patients with chronic illnesses appear to be at the highest risk for COVID-19 associated sequelae. Inability to participate in outpatient-based rehabilitation programs and being home-bound can increase the risk for and potential worsening of chronic health conditions. This study evaluated the short-term effects of telerehabilitation on patients’ walk test performance and health related quality of life (HRQoL).  Methods: 47 patients (23 cardiovascular, 15 pulmonary, 9 oncology) participated in the telerehabilitation program. At baseline and following a 1-month intervention, patients had their 6-minute walk test distance (6MWTD) and HRQoL assessed. Average daily step counts were measured by the PACER App. Conclusion: Our results indicate that a short-term, supervised virtual telerehabilitation program had significant positive effects on 6MWTD and HRQoL in cardiac, pulmonary and oncology patients during COVID-19

Subclinical coronary atherosclerosis identified by coronary computed tomographic angiography in asymptomatic morbidly obese patients

Obesity is a common public health problem and obese individuals in particular have a disproportionate incidence of acute coronary events. This study was undertaken to identify coronary artery lesions as well as associated clinical features, risk factors and demographics in patients with a body mass index (BMI) >40 kg/m2 without known coronary artery disease (CAD). Morbidly obese subjects were prospectively recruited to undergo coronary computed tomographic angiography (CCTA) using a dual-source computed tomography (CT) system. CAD was defined as the presence of any atherosclerotic lesion in any one coronary artery segment. The presence, location, and severity of atherosclerosis were related to patient characteristics. Forty-one patients (28 women, mean age, 50.4±10.0 years, mean BMI, 43.8±4.8 kg/m2) served as the study population. Of these, 25 patients (61%) had at least one coronary stenosis. All but 2 patients within the CAD cohort had coronary artery calcium (CAC) scores >0, and most plaques identified (75.4%) were non-calcified. There was a predilection of calcified and non-calcified atherosclerosis involving the left anterior descending (LAD) coronary artery compared with other coronary segments. Univariate predictors of CAD included older age, dyslipidemia, and diabetes. In this preliminary study of young morbidly obese patients, CCTA detected a high prevalence of calcified and non-calcified CAD, although the later predominated

Impact of Cardiorespiratory Fitness on Survival in Men with Low Socioeconomic Status

Aims Although both low socioeconomic status (SES) and poor cardiorespiratory fitness (CRF) are associated with increased chronic disease and heightened mortality, it remains unclear whether moderate-to-high levels of CRF are associated with survival benefits in low SES populations. This study evaluated the hypothesis that SES and CRF predict all-cause mortality and cardiovascular disease mortality and that moderate-to-high levels of CRF may attenuate the association between low SES and increased mortality. Methods This study included 2368 men, who were followed in the Kuopio Ischaemic Heart Disease Study cohort. CRF was directly measured by peak oxygen uptake during progressive exercise testing. SES was characterized using self-reported questionnaires. Results During a 25-year median follow-up, 1116 all-cause mortality and 512 cardiovascular disease mortality events occurred. After adjusting for potential confounders, men with low SES were at increased risks for all-cause mortality (hazard ratio 1.49, 95% confidence interval: 1.30–1.71) and cardiovascular disease mortality (hazard ratio1.38, 1.13–1.69). Higher levels of CRF were associated with lower risks of all-cause mortality (hazard ratio 0.54, 0.45–0.64) and cardiovascular disease mortality (hazard ratio 0.53, 0.40–0.69). In joint associations of SES and CRF with mortality, low SES-unfit had significantly higher risks of all-cause mortality (hazard ratio 2.15, 1.78–2.59) and cardiovascular disease mortality (hazard ratio 1.95, 1.48-2.57), but low SES-fit was not associated with a heightened risk of cardiovascular disease mortality (hazard ratio 1.09, 0.80-1.48) as compared with their high SES-fit counterparts. Conclusion Both SES and CRF were independently associated with subsequent mortality; however, moderate-to-high levels of CRF were not associated with an excess risk of cardiovascular disease mortality in men with low SES.peerReviewe

Updating ACSM's Recommendations for Exercise Preparticipation Health Screening

The purpose of the American College of Sports Medicine's (ACSM) exercise preparticipation health screening process is to identify individuals who may be at elevated risk for exercise-related sudden cardiac death and/or acute myocardial infarction. Recent studies have suggested that using the current ACSM exercise preparticipation health screening guidelines can result in excessive physician referrals, possibly creating a barrier to exercise participation. In addition, there is considerable evidence that exercise is safe for most people and has many associated health and fitness benefits; exercise-related cardiovascular events are often preceded by warning signs/symptoms; and the cardiovascular risks associated with exercise lessen as individuals become more physically active/fit. Consequently, a scientific roundtable was convened by the ACSM in June 2014 to evaluate the current exercise preparticipation health screening recommendations. The roundtable proposed a new evidence-informed model for exercise preparticipation health screening on the basis of three factors: 1) the individual's current level of physical activity, 2) presence of signs or symptoms and/or known cardiovascular, metabolic, or renal disease, and 3) desired exercise intensity, as these variables have been identified as risk modulators of exercise-related cardiovascular events. Identifying cardiovascular disease risk factors remains an important objective of overall disease prevention and management, but risk factor profiling is no longer included in the exercise preparticipation health screening process. The new ACSM exercise preparticipation health screening recommendations reduce possible unnecessary barriers to adopting and maintaining a regular exercise program, a lifestyle of habitual physical activity, or both, and thereby emphasize the important public health message that regular physical activity is important for all individuals

RELIABILITY AND ACCURACY OF A STANDARDIZED SHALLOW WATER RUNNING TEST TO DETERMINE CARDIORESPIRATORY FITNESS

A standardized fitness assessment is critical for the development of an individualized exercise prescription. Although the benefits of aquatic exercise have been well established, there remains the need for a standardized nonswimming protocol to accurately assess cardiorespiratory fitness (CRF) in shallow water. The present investigation was designed to assess (a) the reliability of a standardized shallow water run (SWR) test of CRF and (b) the accuracy of a standardized SWR compared with a land-based treadmill (LTM)test. Twenty-three healthy women (20 6 3 years), with body mass index (23.5 6 3 kg$m22), performed 2 shallow water peak oxygen consumption (V_ O2peak) running tests (SWRa and SWRb), and 1 V_ O2max LTM. Intraclass correlation coefficients indicated moderately strong reliability for V_ O2peak (ml$kg21$min21) (r = 0.73, p , 0.01), HR peak (b$min21) (r = 0.82; p , 0.01), and O2pulse (V_ O2 [ml$kg21$min21]$HR [b$min21]) (r = 0.77, p , 0.01). Using paired t-tests and Pearson’s correlations, SWR V_ O2peak and HR peak were significantly lower than during LTM (p # 0.05) and showed moderate correlations of 0.60 and 0.58 (p , 0.001) to LTM. O2pulse was similar (p . 0.05) for the SWR and LTM tests with a moderate correlation of 0.63. A standardized SWR test asa measure of CRF is a reliable, and to some degree, valid alternative to conventional protocols and may be used by strength and conditioning professionals to measure program outcomes and monitor training progress. Furthermore, this protocol provides a water-based option for CRF assessment among healthy women and offers insight toward the development of an effective protocol that can accommodate individuals with limited mobility, or those seeking less musculoskeletal impact from traditional land-based types of training