Impact of unhealthy lifestyle on cardiorespiratory fitness and heart rate recovery of medical science students

Background: Medical science students represent valuable labour resources for better future medicine and medical technology. However, little attention was given to the health and well-being of these early career medical science professionals. The aim of this study is to investigate the impact of lifestyle components on cardiorespiratory fitness and heart rate recovery measured after moderate exercise in this population. Methods: Volunteers without documented medical condition were recruited randomly and continuously from the first-year medical science students during 2011-2014 at the University of Surrey, UK. Demographics and lifestyle components (the levels of smoking, alcohol intake, exercise, weekend outdoor activity and screen-time, daily sleep period, and self-assessment of fitness) were gathered through pre-exercise questionnaire. Cardiorespiratory fitness (VO2max) and heart rate recovery were determined using Åstrand–Rhyming submaximal cycle ergometry test. Data were analysed using SPSS version 25. Results: Among 614 volunteers, 124 had completed both lifestyle questionnaire and the fitness test and were included for this study. Within 124 participants (20.6±4 years), 46.8% were male and 53.2% were female, 11.3% were overweight and 8.9% were underweight, 8.9% were current smokers and 33.1% consumed alcohol beyond the UK recommendation. There were 34.7% of participants admitted to have <3 h/week of moderate physical activity assessed according to UK Government National Physical Activity Guidelines and physically not fit (feeling tiredness). Fitness test showed that VO2max distribution was inversely associated with heart rate recovery at 3 min and both values were significantly correlated with the levels of exercise, self-assessed fitness and BMI. Participants who had <3h/week exercise, or felt not fit or were overweight had significantly lower VO2max and heart rate recovery than their peers. Conclusion: One in three new medical science students were physically inactive along with compromised cardiorespiratory fitness and heart rate recovery, which put them at risk of cardiometabolic diseases. Promoting healthy lifestyle at the beginning of career is crucial in keeping medical science professionals healthy

Association between Changes in Muscle Quality with Exercise Training and Changes in Cardiorespiratory Fitness Measures in Individuals with Type 2 Diabetes Mellitus: Results from the HART-D Study

Introduction: Type 2 diabetes mellitus (T2DM) is associated with a reduction in muscle quality. However, there is inadequate empirical evidence to determine whether changes in muscle quality following exercise are associated with improvement in cardiorespiratory fitness (CRF) in individuals with T2DM. The objective of this study was to investigate the association between change in muscle quality following a 9-month intervention of aerobic training (AT), resistance training (RT) or a combination of both (ATRT) and cardiorespiratory fitness (CRF) in individuals with T2DM. Material and Methods A total of 196 participants were randomly assigned to a control, AT, RT, or combined ATRT for a 9-months intervention. The exposure variable was change in muscle quality [(Post: leg muscle strength/leg muscle mass)-[(Pre: leg muscle strength/leg muscle mass)]. Dependent variables were change in CRF measures including absolute and relative VO2peak, and treadmill time to exhaustion (TTE) and estimated metabolic equivalent task (METs). Results Continuous change in muscle quality was independently associated with change in absolute (β = 0.015; p = 0.019) and relative (β = 0.200; p = 0.005) VO2peak, and TTE (β = 0.170; p = 0.043), but not with estimated METs (p > 0.05). A significant trend was observed across tertiles of change in muscle quality for changes in absolute (β = 0.050; p = 0.005) and relative (β = 0.624; p = 0.002) VO2peak following 9 months of exercise training. No such association was observed for change in TTE and estimated METs (p > 0.05). Discussion: The results from this ancillary study suggest that change in muscle quality following exercise training is associated with a greater improvement in CRF in individuals with T2DM. Given the effect RT has on increasing muscle quality, especially as part of a recommended training program (ATRT), individuals with T2DM should incorporate RT into their AT regimens to optimize CRF improvement

Do obese but metabolically normal women differ in intra-abdominal fat and physical activity levels from those with the expected metabolic abnormalities? A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Obesity remains a major public health problem, associated with a cluster of metabolic abnormalities. However, individuals exist who are very obese but have normal metabolic parameters. The aim of this study was to determine to what extent differences in metabolic health in very obese women are explained by differences in body fat distribution, insulin resistance and level of physical activity.</p> <p>Methods</p> <p>This was a cross-sectional pilot study of 39 obese women (age: 28-64 yrs, BMI: 31-67 kg/m²) recruited from community settings. Women were defined as 'metabolically normal' on the basis of blood glucose, lipids and blood pressure. Magnetic Resonance Imaging was used to determine body fat distribution. Detailed lifestyle and metabolic profiles of participants were obtained.</p> <p>Results</p> <p>Women with a healthy metabolic profile had lower intra-abdominal fat volume (geometric mean 4.78 l [95% CIs 3.99-5.73] vs 6.96 l [5.82-8.32]) and less insulin resistance (HOMA 3.41 [2.62-4.44] vs 6.67 [5.02-8.86]) than those with an abnormality. The groups did not differ in abdominal subcutaneous fat volume (19.6 l [16.9-22.7] vs 20.6 [17.6-23.9]). A higher proportion of those with a healthy compared to a less healthy metabolic profile met current physical activity guidelines (70% [95% CIs 55.8-84.2] vs 25% [11.6-38.4]). Intra-abdominal fat, insulin resistance and physical activity make independent contributions to metabolic status in very obese women, but explain only around a third of the variance.</p> <p>Conclusion</p> <p>A sub-group of women exists who are metabolically normal despite being very obese. Differences in fat distribution, insulin resistance, and physical activity level are associated with metabolic differences in these women, but account only partially for these differences. Future work should focus on strategies to identify those obese individuals most at risk of the negative metabolic consequences of obesity and on identifying other factors that contribute to metabolic status in obese individuals.</p

EFFECT OF BLOOD FLOW RESTRICTION TRAINING AT VARIABLE LOADS AND REPETITION SPEEDS ON MUSCULAR FATIGUE

John C. Sieverdes, Korey C. Little, Wesley D. Dudgeon. College of Charleston, Charleston, SC. BACKGROUND: Blood flow restriction (BFR) is a training method used to restrict venous return by partially occluding limbs to increase metabolic stress using lighter loads during exercise training. This modality has been proven to increase muscular conditioning and elicit changes in muscular cross-sectional area and endurance. Conventional BFR training methodologies often utilize a 30-15-15-15 rep scheme. The purpose of this study is to investigate the feasibility of other exercise parameters on time-under tension (TUT) and load interactions on muscular fatigue. METHODS: Five resistance-trained men (mean age = 21.0 [SD1.9] yrs) attended 3 laboratory visits. Baseline biceps brachii peak torque was assessed using an isokinetic arm curl protocol on a Biodex dynamometer. Four BFR arm-curl conditions (i.e., all 30% occlusion with 30 second rest between sets) were randomized to each arm for per visit resulting in 5 measures for each condition (A: standard 30% 1RM, 30,15,15,15 reps 3 sec/rep; B: 50% 1RM, 15, 10, 10, 10 reps, 6 sec/rep; C: 30%1RM, 12, 9, 9, 9 reps, 6 sec/rep; D:50%1RM, 15, 10, 10, 10, 10, 3 sec/rep. Blood lactate was assessed for 5 minutes after the exercise with peak arm isokinetic curl torque measured at 7 minutes. RESULTS: Participants were able to complete 91% of condition A’s repetitions, 41% of condition B, 99% of condition C, and 68% of condition D. RPE was highest for condition B, followed by D, A, then C. Muscular time by load burden was calculated by TUT and TUT x load. Condition A had notably higher session TUT (191 sec; p = .035) and TUT x load = 7388.11 sec*kg (p = .001) compared to the next highest condition C (TUT = 109, TUT * load = 1994.9 sec*kg. Non-statistically significant changes in max isokinetic torque between baseline and conditions showed fatigue for A (-3.9 [SD8.62]) but not for B (1.27 [SD 11.04]), C (3.47 [SD 10.17]), or D (2.17 [SD 9.4]). Peak lactate trended higher for condition A at 3.8 (SD.86) and B at 3.5 (SD.61) with conditions D (3.0 [SD1.02]) and C (2.4 [SD.68]) being lower (p-value = .074). CONCLUSION: Increasing the %1RM and or slowing rep speed resulted in participants not meeting the repetition targets and resulted in significantly lower exercise volume than the standard 30%1RM with a 30, 15, 15, 15 repetition scheme

ROLE OF SHORT DURATION INTERMITTENT FASTING ON ACUITY AND BODY COMPOSITION IN YOUNG ADULT FEMALES

Lauren P. Durkee, John C. Sieverdes, Wesley D. Dudgeon. College of Charleston, Charleston, SC. BACKGROUND: Intermittent fasting (IF) is a dietary method to restrict caloric intake during a limited time of day. Clinical trials have found mixed results in changes of body composition and improved cognitive affective states such as concentration and mental acuity. Evidence to date has predominantly focused on middle-aged adults with pre-existing conditions. Therefore, the primary purpose of this feasibility study was to explore the effects of short-term (4-weeks) IF on mental acuity in young women, with secondary interest changes in body composition. METHODS: Twenty-two female subjects were randomized to either IF (n = 11) or a control groups (n = 11). The IF group was instructed to only consume calories in an 8-hour window each day for 4 weeks without intentionally changing the type/amounts of food they consumed. Baseline, mid-point and follow-up physical measures included Dual-X-ray absorptiometry (DEXA) to assess body composition while acuity testing included Cogstate computer-based testing with additional measures of alertness (i.e., Zogim-A and fatigue (FSS)). RESULTS: No statistically significant differences between groups were found for Cogstate testing measurements including psychomotor function, information processing speed, visual attention, visual learning, working memory and attention or for FSS or Zogim-A scales. IF group analysis showed improvements in visual learning (i.e. One Card Learning test) at 2 weeks (delta = .077 [SD.11], p = .05) and at 4 weeks (delta = .078 [SD .06], p = .002) with effect sizes of .674 and 1.30, respectively. Additionally, both groups increased their paired associate learning scores at 2 weeks (IF: p = .02, Cohen’s d = .832; control: p = .10 Cohen’s d = .884) and 4 weeks (IF: p = .001, Cohen’s d = 1.346, control: p = .023, Cohen’s d = .808). There were no observed changes in weight status, body fat, or lean mass over the course of the 4-week intervention. CONCLUSIONS: This pilot feasibility study found small changes in the visual learning domain of acuity during the 4-week trial IF trial. Implications of the trial suggest that other cognitive or acuity measures may be more sensitive to IF as the present study reported minimal findings. Future studies could focus on longer intervention durations, other cognitive measures or investigate diet restriction in conjunction with IF

Effects of exercise on dual-task ability and balance in older adults: a systematic review.

The interest in research on exercise and physical activity effects on dual-task performance has grown rapidly in the last decade due to the aging global population. Most of the available literature is focused on exercise benefits for the risk of falls, attention, and gait-speed; however, there is a lack of evidence reporting the exercise effects on balance in healthy older adults during dual-task performance. The objective of this study was to critically review the existing evidence of a potential relationship between exercise and improvement of static and dynamic balance during dual-task in healthy older adults and secondary outcomes in other physical and cognitive indices. A systematic search using online databases was used to source articles. Inclusion criteria included articles classified as randomized controlled trials (RCT), controlled trials (CT) and uncontrolled trials (UT). Moreover, the studies had to include an exercise or physical activity protocol in the intervention. Eight studies met the eligibility criteria and included 6 RCTs, 1 CT, and 1 UT. Several limitations were identified, mainly focused on the lack of a common and standardized method to evaluate the balance during the dual-task performance. Additionally, exercise protocols were extensively different, and generally lacked reporting measures. Preliminary findings show that the current body of evidence does not support that exercises used in these interventions entail clear and noteworthy benefits on static or dynamic balance improvements during dual-task performance. Innovative measures and exercise programs may need to be developed before efficacious screening and treatment strategies can be used in clinical settings

Reliability and validity of the Mywellness Key physical activity monitor

John C Sieverdes,1 Eric E Wickel,2 Gregory A Hand,3 Marco Bergamin,4 Robert R Moran,5 Steven N Blair3,51Medical University of South Carolina, College of Nursing and Medicine, Charleson, SC, 2University of Tulsa, Exercise and Sport Science, Tulsa, OK, 3University of South Carolina, Department of Exercise Science, Division of Health Aspects of Physical Activity, Arnold School of Public Health, Columbia, SC, USA; 4University of Padova, Department of Medicine, Sports Medicine Division, Padova, Italy; 5University of South Carolina, Department of Epidemiology and Biostatistics, Arnold School of Public Health, Columbia, SC, USABackground: This study evaluated the reliability and criterion validity of the Mywellness Key accelerometer (MWK) using treadmill protocols and indirect calorimetry.Methods: Twenty-five participants completed two four-stage 20-minute treadmill protocols while wearing two MWK accelerometers. Reliability was assessed using raw counts. Validity was assessed by comparing the estimated VO2 calculated from the MWK with values from respiratory gas exchange.Results: Good overall and point estimates of reliability were found for the MWK (all intraclass correlations &amp;gt; 0.93). Generalizability theory coefficients showed lower values for running speed (0.70) versus walking speed (all &amp;gt; 0.84), with the majority of the overall percentage of variability derived from the participant (68%&amp;ndash;88% of the total 100%). Acceptable validity was found overall (Pearson&amp;rsquo;s r = 0.895&amp;ndash;0.902, P &amp;lt; 0.0001), with an overall mean absolute error of 16.22% and a coefficient of variance of 16.92%. Bland-Altman plots showed an overestimation of energy expenditure during the running speed, but total kilocalories were underestimated during the protocol by approximately 10%.Conclusion: Good validity was found during light and moderate walking, while running was slightly overestimated. The MWK may be useful for clinicians and researchers interested in promotion or assessment of physical activity.Keywords: physical activity, accelerometer, health monito

Effect of Exercise on Dual-Task and Balance on Elderly in Multiple Disease Conditions.

Investigations on how exercise and physical activity affect dual-task (DT) performance in the elderly are growing rapidly due to the fact that DT activities are commonplace with activities of daily living. Preliminary evidence has shown the benefit in exercise on DT balance, though it is unclear to what extent the effect exercise has on DT performance in elderly subjects with disease conditions, including subjects with a high risk of falls. Hence, the objective of this study was to critically review the existing evidence of a potential relationship between exercise and improvement of static and dynamic balance during DT conditions as well as secondary outcomes in elderly subjects with different disease conditions. A systematic search using online databases was performed to source documents. Inclusion criteria sourced articles classified as randomized controlled trials (RCT), controlled trials (CT) and uncontrolled trials (UT). Moreover, the studies had to administrate an exercise or physical activity protocol in the intervention. Seventeen studies met the eligibility criteria and were comprised of 12 RCTs, 3 CTs, and 2 UTs. Overall, 13 studies supported exercise being effective to improve parameters of static and dynamic balance during single or DT conditions. Despite the heterogeneity of pathologic conditions, exercise showed similar benefits to improve function in two main areas: neurological conditions and frailty conditions. The lack of a common method to assess DT performance limited the ability to compare different interventions directly. Future research is warranted to study the optimal dose and exercise modalities to best reduce the risk of falls in the elderly with multiple disease conditions