Loss Of Cardiorespiratory Fitness Research Articles

Pilot Study-Estimated VO2max via Modified Harvard Step Test (MHST) in Anterior Cruciate Ligament Injury Patients Undergoing Pre-Op Rehabilitation

Introduction: Anterior Cruciate Ligament (ACL) injury ranging from partial to full thickness tear causes much dysfunction physically and psychologically. It affects both daily & sporting activities with potential of creating long term complications such as post-traumatic osteoarthritis of knee, functional limitations, increase in body mass index (BMI) and loss of cardiorespiratory fitness. Cardiorespiratory fitness is an important indicator for functional and fitness capacity and VO2max is used to measure cardiorespiratory fitness. VO2max is the maximum rate of oxygen consumption during a vigorous exercise. Cardiopulmonary exercise testing is usually done on a treadmill with gaseous exchange system, a process that is time consuming, expensive and difficult to assess and not available in our public health setting. Modified Harvard step test is easy to do, cost friendly and allows mass testing to measure cardiorespiratory fitness (VO2max) however there are inadequate data on ACL injury and its influence on cardiorespiratory fitness using modified Harvard step test. Method: A prospective study was done using patients attending Sports Medicine Gym Hospital Tuanku Ja’afar 2023 and data from 20 patients who were undergoing pre-ACL reconstruction rehabilitation were evaluated. Patients were divided into two groups according to post trauma duration; (<6 months of injury and rehabilitation and >6 months injury and rehabilitation). Patients were required to do modified Harvard step test and translated into VO2max scores. Anthropometric data were also taken from patients. Results: The mean age for our study is 21.9±4.3 years. The mean VO2max for the entire participant was 43.2ml/kg/min. Mean VO2max for groups <6 months injury rehabilitation and >6 months injury rehabilitation was at 35.4±1.8 ml/kg/min and 49.0± 5.8ml/kg/min respectively. We report difference in both groups VO2max Conclusion: Cardiorespiratory fitness is often reduced during earlier phase of injury due to inability to perform aerobic exercises. Progressive rehabilitation can improve cardiorespiratory fitness, aid in patients return to sports and reduces morbidity post operatively. Modified Harvard step test is a reliable and cost-effective method to test VO2max. It is also important to increase cardiorespiratory fitness to maintain healthy BMI.

Loss of cardiorespiratory fitness and its recovery following two weeks of head-down bed rest and the protective effects of exercise in 55- to 65-yr-old adults.

Cardiorespiratory fitness declines with age and this decline can be accelerated by inactivity and bed rest. Recovery of fitness is possible, but the timeline in 55- to 65-yr-old adults is unknown. Furthermore, the effectiveness of exercise to prevent deconditioning during bed rest is unexplored in this age group. Twenty-two adults (11 women, 59 ± 3 yr) completed 2 wk of strict 6° head-down bed rest (HDBR). Half of the participants performed approximately 1 h of daily exercises, including high-intensity interval cycling, aerobic cycling, and upper- and lower-body resistance training, whereas control participants were inactive. Step-incremental cycling tests to exhaustion were conducted pre-HDBR and at three times during the recovery phase (day 1 or 2, day 6, and 4 wk) to assess peak oxygen uptake (V̇o2). Peak V̇o2 was reduced in the control group throughout the first 6 days of recovery, but did return to pre-HDBR levels by the 4-wk recovery time point (interaction: P = 0.002). In the exercise group, peak V̇o2 was not different at any time point during recovery from pre-HDBR. Ventilatory threshold V̇o2 (interaction: P = 0.002) and heart rate at 15 W (interaction: P = 0.055) mirrored the changes in peak V̇o2 in each respective group. Overall, this study showed that approximately 1 h of daily exercise effectively protected 55- to 65-yr-old adults' cardiorespiratory fitness during 2 wk of HDBR. HDBR without exercise countermeasures caused substantial reductions in cardiorespiratory fitness, but fitness recovered within 4 wk of resuming daily activities. These findings highlight the importance of physical activity in late middle-age adults.NEW & NOTEWORTHY We report the complete time-course of cardiorespiratory fitness recovery back to baseline levels following 2 wk of head-down bed rest in 55- to 65-yr-old adults and found that multimodal training, consisting of high-intensity interval, aerobic and resistive exercises, performed throughout the 2 wk of head-down bed rest prevented reductions in cardiorespiratory fitness.

The Impact of Training on the Loss of Cardiorespiratory Fitness in Aging Masters Endurance Athletes.

Elite masters endurance athletes are considered models of optimal healthy aging due to the maintenance of high cardiorespiratory fitness (CRF) until old age. Whereas a drop in VO2max in masters athletes has been broadly investigated, the modifying impact of training still remains a matter of debate. Longitudinal observations in masters endurance athletes demonstrated VO2max declines between −5% and −46% per decade that were closely related to changes in training volume. Here, using regression analyses, we show that 54% and 39% of the variance in observed VO2max decline in male and female athletes, respectively is explained by changes in training volume. An almost linear VO2max decrease was observed in studies on young and older athletes, as well as non-athletes, starting a few days after training cessation, with a decline of as much as −20% after 12 weeks. Besides a decline in stroke volume and cardiac output, training cessation was accompanied by considerable reductions in citrate synthase and succinate dehydrogenase activity (reduction in mitochondrial content and oxidative capacity). This reduction could largely be rescued within similar time periods of training (re)uptake. It is evident that training reduction or cessation leads to a considerably accelerated VO2max drop, as compared to the gradual aging-related VO2max decline, which can rapidly nullify many of the benefits of preceding long-term training efforts.

Impact of a year-round school calendar on children's BMI and fitness: Final outcomes from a natural experiment.

Structure may mitigate children's accelerated summer BMI gain and cardiorespiratory-fitness (CRF) loss. Examine BMI and CRF change during school and summer for year-round and traditional calendar school children. Three schools (N=2279, 1 year-round) participated in this natural experiment. Children's BMI z-score (zBMI) and CRF (PACER laps) were measured from 2017 to 2019 each May/August. Mixed effects regression estimated monthly zBMI and CRF change during school/summer. Secondary analyses examined differences by weight status and race. Spline regression models estimated zBMI and CRF growth from kindergarten-sixth grade. Compared to traditional school, children attending a year-round school gained more zBMI (difference=0.015; 95CI=0.002, 0.028) during school, and less zBMI (difference=-0.029; 95CI=-0.041, -0.018), and more CRF (difference=0.834; 95CI=0.575, 1.093) monthly during summer. Differences by weight status and race were observed during summer and school. Growth models demonstrated that the magnitude of overall zBMI and CRF change from kindergarten-sixth grade was similar for year-round or traditional school children. Contrary to traditional school children zBMI increased during the traditional 9-month school calendar and zBMI decreased during the traditional summer vacation for year-round school children. Structured summer programming may mitigate accelerated summer BMI gain and CRF loss especially for overweight or obese, and/or Black children.

Childhood obesity and SARS-CoV2: dangerous liaisons

ABSTRACT BACKGROUND: Nowadays obesity and CoronaVIrus Disease-19 (COVID-19), for some extent, represent two major public health problems worldwide. These diseases, albeit extremely different, have a pandemic pattern of diffusion and have enormous direct and indirect effects both on health and lifestyle.AIM: Aim of our narrative review was to analyze in the pediatric population, the relationship between these two diseases using a holistic approach.MATERIALS AND METHODS: We performed a quasi-review with a systematic literature search through the Cochrane Library and Medline/PubMed databases from 1 January 2013 to 1 October 2020. Two authors independently extracted data using predefined data fields and rated study quality. Two main key words were considered, obesity and COVID-19, pointing a particular focus on pediatric patients. We also analysed the relationship between obesity and COVID-19 in adults for comparison.CONCLUSION: Evidences showed that during quarantine due to COVID-19, children and adolescents were physically less active, have much longer screen time exposure, sleep patterns disturbances, and less favorable diets, possibly resulting in weight gain and in a loss of cardio-respiratory fitness. Such negative effects on health are likely to be much worse in subjects that are overweight or have obesity. Moreover, stressors emerging from the prolonged national lock-down around the world and from social distancing could have even more problematic and enduring effects considering that obese children are more susceptible to psychiatric disorders.Obesity represents also a risk factor for COVID-19 severity in younger adults but at the moment in pediatric population we have very limited data.Public health interventions are urgently called in order to promote an active lifestyle and engagement in social activities in children and possibly to mitigate the adverse impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in pediatric subjects that are overweight or have obesity.

Physical deterioration and adaptive recovery in physically inactive breast cancer patients during adjuvant chemotherapy: a randomised controlled trial

Cardiorespiratory fitness is an independent risk factor for cardiovascular disease and shortened life expectancy in breast cancer survivors. This randomised controlled trial (n = 153) was designed for patients with a physically inactive lifestyle prediagnosis and concurrently referred to adjuvant chemotherapy. We compared two 12-week exercise interventions aimed at physiological and patient-reported outcomes (cardiorespiratory fitness, muscle strength, metabolic markers, physical activity, pain, fatigue), including a 39-week follow-up. A supervised hospital-based moderate to high intensity group exercise intervention was compared to an instructed home-based individual pedometer intervention. The two 12-week interventions included oncologists’ recommendations and systematic health counselling. Outcomes were measured at baseline and week 6, 12 and 39. Primary outcome cardiorespiratory fitness declined significantly during chemotherapy and was restored in both interventions at follow-up. The interventions effectively engaged breast cancer patients in sustaining physical activities during and following adjuvant treatment. A composite metabolic score improved significantly. Positive cardiorespiratory fitness responders had improved clinical effects on fatigue, pain and dyspnoea versus negative responders. We conclude that a loss of cardiorespiratory fitness among physically inactive breast cancer patients may be restored by early initiated interventions and by adapting to physical activity recommendations, leading to a decreased cardiovascular risk profile in breast cancer survivors.

Cardio-Oncology Rehabilitation to Manage Cardiovascular Outcomes in Cancer Patients and Survivors: A Scientific Statement From the American Heart Association.

Cardiovascular disease is a competing cause of death in patients with cancer with early-stage disease. This elevated cardiovascular disease risk is thought to derive from both the direct effects of cancer therapies and the accumulation of risk factors such as hypertension, weight gain, cigarette smoking, and loss of cardiorespiratory fitness. Effective and viable strategies are needed to mitigate cardiovascular disease risk in this population; a multimodal model such as cardiac rehabilitation may be a potential solution. This statement from the American Heart Association provides an overview of the existing knowledge and rationale for the use of cardiac rehabilitation to provide structured exercise and ancillary services to cancer patients and survivors. This document introduces the concept of cardio-oncology rehabilitation, which includes identification of patients with cancer at high risk for cardiac dysfunction and a description of the cardiac rehabilitation infrastructure needed to address the unique exposures and complications related to cancer care. In this statement, we also discuss the need for future research to fully implement a multimodal model of cardiac rehabilitation for patients with cancer and to determine whether reimbursement of these services is clinically warranted.

Trajectories of cardio-metabolic health in successful aging.

Maximal oxygen uptake (V̇O2max ) and muscle mass decrease with age. The loss of cardiorespiratory fitness and muscle strength is accelerated with physical inactivity and has well-documented consequences for morbidity and all-cause mortality. Participation in exercise training programs will improve one or more of the cardio-metabolic risk factors, but the long-term effects of such programs are questionable. Here, we re-examined 25 old (72±4years.) men and women who considered him/herself as "success-full agers" and were participants in a 3-month alpine skiing training program 6years earlier. The program focused on healthy aging and included health questionnaires, measurement of lipids and glycemic parameters in blood and a VO2max test. Thirteen and 12 subjects were in the intervention (IG) and the control group (CG), respectively. In response to the training program, subjects improved their cardio-metabolic risk factors. However, after 6years all positive effects had disappeared. Approximately 80% of the subjects had total cholesterol and LDL cholesterol above and HDL cholesterol below the recommended values, but these subjects remained the most metabolically deteriorated, including an increase in fasting glucose concentrations. We conclude that people seem to follow their individual trajectory in terms of cardio-metabolic risk factors, and participation in a relatively short lasting exercise training program with emphasis on healthy aging does not change that. Long-lasting change in lifestyle probably requires a continued attentional focus, goal setting, and feedback.

Cardiorespiratory fitness in breast cancer patients undergoing adjuvant therapy

Purpose. The aim of this work was to investigate cardiorespiratory fitness in breast cancer patients at different time points of anti-cancer treatment.Patients and methods. Non-metastatic breast cancer patients (n = 222, mean age 55 years) were categorized into four subgroups according to their treatment status. Cardiopulmonary exercise testing (CPET) was used to measure patients’ cardiorespiratory fitness, including oxygen delivery and metabolic muscle function. Testing was performed by bicycle ergometry, and maximal oxygen uptake (VO2peak) was measured. Heart rate during exercise at 50 watts (HR50) was assessed as a cardiocirculatory parameter and ventilatory threshold (VT) was used as an indicator of the O2 supply to muscle. Analysis of covariance was used to estimate the impact of different cancer treatments on cardiorespiratory fitness with adjustment for clinical factors.Results. Submaximal measures were successfully assessed in 220 (99%) and 200 (90%) patients for HR50 and VT, while criteria for maximal exercise testing were met by 176 patients (79%), respectively. The mean VO2peak was 20.6 ± 6.7 ml/kg/min, mean VT 10.7 ± 2.9 ml/min/kg and mean HR50 112 ± 16 beats/min. Chemotherapy was significantly associated with decreased VO2peak, with significantly lower adjusted mean VO2peak among patients post adjuvant chemotherapy compared to patients with no chemotherapy or those who just started chemotherapy regime (all p < 0.01). Patients post adjuvant chemotherapy reached only 63% of the VO2peak level expected for their age- and BMI-category (mean VO2peak 15.5 ± 4.8 ml/kg/min). Similarly, HR50 was significantly associated with treatment. However, VT was not associated with treatment.Conclusion. Breast cancer patients have marked and significantly impaired cardiopulmonary function during and after chemotherapy. Hereby, chemotherapy appears to impair cardiorespiratory fitness by influencing the oxygen delivery system rather than impacting metabolic muscle function. Our findings underline the need of exercise training in breast cancer patients to counteract the loss of cardiorespiratory fitness during the anti-cancer treatment.