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1.
The effect of 2 walking programs on aerobic fitness, body composition, and physical activity in sedentary office employees.
Rodriguez-Hernandez, MG, Wadsworth, DW
PloS one. 2019;(1):e0210447
Abstract
PURPOSE The present study examined changes in body composition, maximum oxygen uptake, and physical activity in sedentary office employees prescribed with two different walking programs during a 10-week intervention. METHODS 68 sedentary employees were randomly assigned to one of three groups: multiple bouts of walking (n = 24 (5 male, 19 female) Age = 46±9, BMI = 30.5±5.78 kg/m2), continuous walking (n = 22 (6 male, 16 female) Age = 48±9, BMI = 30.6±6.2 kg/m2) and the control group (n = 22 (5 male, 17 female) Age = 42±10, BMI = 27.5±5.23 kg/m2). Dual-energy X-ray absorptiometry (iDXA) assessed body composition and a Bruce protocol treadmill test assessed aerobic fitness at baseline and week 11. At baseline, week 6 and week 11 a waist worn accelerometer measured physical activity and sedentary behavior. Physical activity was measured throughout the program with a wrist worn accelerometer. RESULTS The results from the mixed-design ANOVA show that fat mass (p < .000) and fat percentage (p < .000) decreased for all three groups as a main effect of time. Sedentary behavior did not change (p>0.05) for all three groups. Moderate intensity physical activity increased significantly from pre-test to week 6 (p<0.05), then decreased from week 6 to post-test (p<0.05), with no significant changes observed from pre-test to post-test (p>0.05) for all groups. No changes in VO2 were observed (p>0.05) for all groups. CONCLUSIONS Continuous or intermittent walking activity produce similar benefits on body weight, fat mass and body fat percentage in sedentary employees. Meanwhile, intermittent walking allowed these sedentary employees to increase lean mass and fat free mass. Intermittent walking could provide at least similar benefits on body composition compared to a continuous walking program.
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2.
Contemporary Nutrition Strategies to Optimize Performance in Distance Runners and Race Walkers.
Burke, LM, Jeukendrup, AE, Jones, AM, Mooses, M
International journal of sport nutrition and exercise metabolism. 2019;(2):117-129
Abstract
Distance events in Athletics include cross country, 10,000-m track race, half-marathon and marathon road races, and 20- and 50-km race walking events over different terrain and environmental conditions. Race times for elite performers span ∼26 min to >4 hr, with key factors for success being a high aerobic power, the ability to exercise at a large fraction of this power, and high running/walking economy. Nutrition-related contributors include body mass and anthropometry, capacity to use fuels, particularly carbohydrate (CHO) to produce adenosine triphosphate economically over the duration of the event, and maintenance of reasonable hydration status in the face of sweat losses induced by exercise intensity and the environment. Race nutrition strategies include CHO-rich eating in the hours per days prior to the event to store glycogen in amounts sufficient for event fuel needs, and in some cases, in-race consumption of CHO and fluid to offset event losses. Beneficial CHO intakes range from small amounts, including mouth rinsing, in the case of shorter events to high rates of intake (75-90 g/hr) in the longest races. A personalized and practiced race nutrition plan should balance the benefits of fluid and CHO consumed within practical opportunities, against the time, cost, and risk of gut discomfort. In hot environments, prerace hyperhydration or cooling strategies may provide a small but useful offset to the accrued thermal challenge and fluid deficit. Sports foods (drinks, gels, etc.) may assist in meeting training/race nutrition plans, with caffeine, and, perhaps nitrate being used as evidence-based performance supplements.
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3.
A lifestyle intervention of weight loss via a low-carbohydrate diet plus walking to reduce metabolic disturbances caused by androgen deprivation therapy among prostate cancer patients: carbohydrate and prostate study 1 (CAPS1) randomized controlled trial.
Freedland, SJ, Howard, L, Allen, J, Smith, J, Stout, J, Aronson, W, Inman, BA, Armstrong, AJ, George, D, Westman, E, et al
Prostate cancer and prostatic diseases. 2019;(3):428-437
Abstract
PURPOSE The objective of this study was to test a low-carbohydrate diet (LCD) plus walking to reduce androgen deprivation therapy (ADT)-induced metabolic disturbances. MATERIALS AND METHODS This randomized multi-center trial of prostate cancer (PCa) patients initiating ADT was designed to compare an LCD (≤20g carbohydrate/day) plus walking (≥30 min for ≥5 days/week) intervention vs. control advised to maintain usual diet and exercise patterns. Primary outcome was change in insulin resistance by homeostatic model assessment at 6 months. To detect 20% reduction in insulin resistance, 100 men were required. The study was stopped early after randomizing 42 men due to slow accrual. Secondary outcomes included weight, body composition, lipids, and prostate-specific antigen (PSA). Changes from baseline were compared between arms using rank-sum tests. RESULTS At 6 months, LCD/walking reduced insulin resistance by 4% vs. 36% increase in control (p = 0.13). At 3 months, vs. control, LCD/walking arm significantly lost weight (7.8kg; p<0.001), improved insulin resistance (↑36%; p = 0.015), hemoglobin A1c (↓3.3%; p = 0.01), high-density lipoprotein (HDL) (↑13%; p = 0.004), and triglyceride (↓37%; p = 0.036). At 6 months, weight loss (10.6kg; p<0.001) and HDL (↑27%; p = 0.003) remained significant. LCD/walking preserved total body bone mineral count (p = 0.025), reduced fat mass (p = 0.002), lean mass (p = 0.036), and percent body fat (p = 0.004). There were no differences in PSA. Limitations include the effect of LCD, weight loss vs. walking instruction are indistinguishable, and small sample size. CONCLUSIONS In an underpowered study, LCD/walking did not improve insulin sensitivity at 6 months. Given most secondary outcomes were improved at 3 months with some remaining improved at 6 months and a secondary analysis showed that LCD/walking reduced insulin resistance over the study, supporting future larger studies of LCD/walking intervention to reduce ADT-induced disturbances.
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4.
Effect of Breaks in Prolonged Sitting or Low-Volume High-Intensity Interval Exercise on Markers of Metabolic Syndrome in Adults With Excess Body Fat: A Crossover Trial.
Freire, YA, Macêdo, GAD, Browne, RAV, Farias-Junior, LF, Bezerra, ÁDL, Fayh, APT, Farias Júnior, JC, Boreskie, KF, Duhamel, TA, Costa, EC
Journal of physical activity & health. 2019;(9):727-735
Abstract
BACKGROUND This study analyzed the effect of walking breaks or low-volume high-intensity interval exercise (LV-HIIE) on markers of metabolic syndrome relative to a day of prolonged sitting. METHODS Twenty-five adults with excess body fat participated in this crossover trial: (1) 10-hour sitting day (SIT), (2) LV-HIIE followed by a sitting day (EX+SIT), and (3) sitting day with 5-minute walking breaks for every 20 minutes (SIT+WB). Glucose and blood pressure (BP) were measured before and 1 hour after 4 meals and 2 hours after lunch. Triglycerides were measured at baseline, 2, and 3.5 hours after lunch. Generalized mixed models were used to identify differences in the area under the curve (AUC) of BP and incremental AUC (iAUC) of glucose and triglycerides among the sessions. RESULTS iAUC-glucose was lower in SIT+WB than SIT (β = -35.3 mg/dL·10 h; 95% confidence interval, -52.5 to -8.2). AUC-diastolic BP was lower in SIT+WB than SIT (β = -14.1 mm Hg·10 h; 95% confidence interval, -26.5 to -1.6) and EX+SIT (β = -14.5 mm Hg·10 h; 95% confidence interval, -26.9 to -2.1). There were no differences in triglycerides and systolic BP levels among the sessions. CONCLUSION Adults with excess body fat present lower glucose and diastolic BP during a day with breaks in sitting time compared with a prolonged sitting day with or without an LV-HIIE session.
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5.
Sedentarism, Physical Activity, Steps, and Neurotrophic Factors in Obese Children.
Mora-Gonzalez, J, Migueles, JH, Esteban-Cornejo, I, Cadenas-Sanchez, C, Pastor-Villaescusa, B, Molina-García, P, Rodriguez-Ayllon, M, Rico, MC, Gil, A, Aguilera, CM, et al
Medicine and science in sports and exercise. 2019;(11):2325-2333
Abstract
PURPOSE This study aimed to examine the associations of sedentary time, physical activity (PA) and step-related behaviors with neurotrophic growth factors. METHODS A total of 97 children with overweight/obesity age 8 to 11 yr participated in this study. Sedentary time, PA, and steps were measured by GT3X+ accelerometers in hip and nondominant wrist. Estimates of light, moderate, vigorous, and moderate-to-vigorous PA (MVPA) were obtained. Steps per daytime, peak 60-, 30-, and 1-min cadence were computed. The time accumulated (min·d) in different cadence bands of steps was also computed from hip accelerometer. Plasma levels of brain-derived neurotrophic factor (BDNF), vascular endothelial growth factor (VEGF), and insulin growth factor-1 (IGF-1) were determined by the XMap technology (Luminex IS 100/200 system, Luminex Corporation, Austin, TX). RESULTS Light PA, moderate PA, MVPA, and the peak 60-min cadence were positively related with BDNF concentrations (all P < 0.05), and only light PA to VEGF (P = 0.048). No association was observed for IGF-1 (P > 0.05). The associations of light PA with BDNF and VEGF disappeared (all P > 0.05) after performing analyses with nondominant wrist-placement data. However, moderate PA and MVPA remained significantly associated with BDNF (both P < 0.05). The time accumulated in cadence bands of 40 to 59 steps per day and 60 to 79 steps per day (i.e., walking at slow pace) was positively associated with plasma BDNF (all P < 0.05). CONCLUSIONS In conclusion, PA is positively related to plasma BDNF, whereas no relationship was observed for VEGF or IGF-1. Higher amounts of time spent in slow walking cadence bands could increment BDNF levels. Exercise-based randomized controlled trials in children with overweight/obesity should be carried out to better understand the influence of PA behaviors on the neurotrophic factors.
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6.
'Walk this way': results from a pilot randomised controlled trial of a health coaching intervention to reduce sedentary behaviour and increase physical activity in people with serious mental illness.
Williams, J, Stubbs, B, Richardson, S, Flower, C, Barr-Hamilton, L, Grey, B, Hubbard, K, Spaducci, G, Gaughran, F, Craig, T
BMC psychiatry. 2019;(1):287
Abstract
BACKGROUND Cardiovascular disease (CVD) is the leading cause of premature death among people with serious mental illness (SMI). Sedentary behaviour (SB) is an independent risk factor for CVD and mortality and people with SMI are highly sedentary. We developed a health coaching intervention called 'Walk this Way' to reduce SB and increase physical activity (PA) in people with SMI and conducted a pilot randomised controlled trial (RCT) to test its feasibility and acceptability. METHODS We randomised people with SMI from three community mental health teams into either the WTW intervention or treatment as usual. The WTW intervention lasted 17 weeks and included an initial education session, fortnightly coaching, provision of pedometers and access to a weekly walking group. Objective SB and PA were measured with accelerometers. Cardiometabolic risk factors and wellbeing measures were collected. RESULTS We recruited 40 people of whom 33 (82.5%) were followed up. 13/20 (65%) of participants allocated to the coaching intervention completed it. In the intervention group SB decreased by 56 min and total PA increased by 32 min per day on average which was sustained 6 months later. There was no change in PA or SB in the control group. When interviewed, participants in the intervention found the intervention helpful and acceptable. No adverse events were reported from the intervention. CONCLUSIONS The intervention was feasible and acceptable to participants. Preliminary results were encouraging with improvement seen in both SB and PA. A larger study is needed to assess the effectiveness of the intervention and address any implementation challenges. TRIAL REGISTRATION ISRCTN Registry identifier: ISRCTN37724980 , retrospectively registered 25 September 2015.
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7.
Diurnal influences of fasted and non-fasted brisk walking on gastric emptying rate, metabolic responses, and appetite in healthy males.
McIver, VJ, Mattin, LR, Evans, GH, Yau, AMW
Appetite. 2019;:104411
Abstract
Growing evidence suggests circadian rhythms, nutrition and metabolism are intimately linked. Intermittent fasting (IMF) has become an increasingly popular intervention for metabolic health and combining IMF with exercise may lead to benefits for weight management. However, little is known about the diurnal variation of fasted exercise. This study aimed to investigate the diurnal influences on gastric emptying rate (GER), metabolic responses, and appetite to fasted and non-fasted exercise. Twelve healthy males completed four 45 min walks in a randomised order. Walks were completed in the morning (AM) and evening (PM) and either fasted (FASTED) or after consumption of a standardised meal (FED). GER of a semi-solid lunch was subsequently measured for 2 h using the 13C breath test. Blood glucose concentration, substrate utilisation, and ratings of appetite were measured throughout. Energy intake was also assessed for the following 24 h. GER Tlag was slower in PM-FASTED compared to AM-FASTED, AM-FED, and PM-FED (75 ± 18 min vs. 63 ± 14 min, P = 0.001, vs. 65 ± 10 min, P = 0.028 and vs. 67 ± 16 min, P = 0.007). Blood glucose concentration was greater in the FED trials in comparison to the FASTED trials pre-lunch (P < 0.05). Fat oxidation was greater throughout exercise in both FASTED trials compared to FED, and remained higher in FASTED trials than fed trials post-exercise until 30 min post-lunch ingestion (all P < 0.05). No differences were found for appetite post-lunch (P > 0.05) or 24 h post-energy intake (P = 0.476). These findings suggest that evening fasted exercise results in delayed GER, without changes in appetite. No compensatory effects were observed for appetite, and 24 h post-energy intake for both fasted exercise trials, therefore, increased fat oxidation holds positive implications for weight management.
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8.
Computer interactions during walking workstation use moderately affects spatial-temporal gait characteristics.
Eggleston, JD, Chavez, EA, Harry, JR, Dufek, JS
Gait & posture. 2019;:200-204
Abstract
BACKGROUND Due to increased sedentary workstyles, active workstations have shown the ability to increase activity while only moderately affecting work ability. However, previous examinations have not examine fine motor mousing tasks on tripping descriptors. RESEARCH QUESTION What affect do mousing tasks of varying target size have on tripping descriptors during walking workstation use? METHODS Three-dimensional kinematic data were collected while participants used a walking workstation completing one baseline and three mousing conditions of varying target sizes. RESULTS Target size main effects (p < 0.001) detected decreased stride length in all experimental conditions, which were supported by moderate effect sizes, and decreased stance width and time in double limb support (p < 0.001 for both comparisons). Stance width differences resulted in large effect sizes between baseline and all conditions, while only moderate effect sizes were observed between time in double limb support in baseline compared to all conditions. No changes in knee flexion range of motion were observed in response to target size (p = 0.278). SIGNIFICANCE These results indicate that walking workstation users shorten their stride length and decrease their base of support while completing mousing tasks. The placement of the upper extremities on the workstation desk likely acted as the primary mechanism to increase stability. It is concluded that performing mousing tasks of varying target size using a walking workstation does not pose greater risk for adverse gait events.
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9.
Progressive changes in walking kinematics throughout pregnancy-A follow up study.
Forczek, W, Ivanenko, Y, Curyło, M, Frączek, B, Masłoń, A, Salamaga, M, Suder, A
Gait & posture. 2019;:518-524
Abstract
BACKGROUND Progressive weight gain and changes in its distribution following pregnancy may be challenging for the gravidas' ability to move in a stable way. RESEARCH QUESTION How is gait kinematics changing throughout pregnancy and to what extend is it affected by physical activity level and energy balance? METHODS 30 women were enrolled. Three experimental sessions were arranged according to the same protocol in the first, second and third trimesters of pregnancy. Walking kinematics at a self-selected speed was registered. The total physical activity (TPA) was assessed from the subjects' questionnaires. Energy balance ('positive', 'balanced' or 'negative') was estimated as the difference between dietary energy intake and energy expenditure during 7 days. RESULTS No significant differences were found in the spatiotemporal variables between experimental sessions. However, the gait analysis revealed significant increments in the single support and base of support (BoS) measures. Generally, the sagittal plane mobility of the lower limb joints did not differ, however, the pelvic tilt increased in late pregnancy. The hip and pelvis angles were significantly different over the gait cycle throughout gestation. The 'balanced' energy was dominant in the first trimester although the relative number of participants with negative balance increased over pregnancy. Overall, gait parameters were independent of the energy balance. However, significant correlation was found between gait parameters, such as BoS, velocity, stride length, and TPA in the advanced pregnancy. SIGNIFICANCE The longitudinal assessment of walking kinematics demonstrates few changes adopted to accommodate for pregnancy. The enlargement of BoS is considered as a strategy to provide safety and stability. The increased pelvic tilt is likely to compensate for changes in the body mass distribution. The physical activity correlates with the BoS measures and stride length and thus may be important for enhancing gait stability.
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10.
Low bone mineral density in ambulatory persons with cerebral palsy? A systematic review.
Mus-Peters, CTR, Huisstede, BMA, Noten, S, Hitters, MWMGC, van der Slot, WMA, van den Berg-Emons, RJG
Disability and rehabilitation. 2019;(20):2392-2402
Abstract
Purpose: Non-ambulatory persons with cerebral palsy are prone to low bone mineral density. In ambulatory persons with cerebral palsy, bone mineral density deficits are expected to be small or absent, but a consensus conclusion is lacking. In this systematic review bone mineral density in ambulatory persons with cerebral palsy (Gross Motor Function Classification Scales I-III) was studied. Materials and methods: Medline, Embase, and Web of Science were searched. According to international guidelines, low bone mineral density was defined as Z-score ≤ -2.0. In addition, we focused on Z-score ≤ -1.0 because this may indicate a tendency towards low bone mineral density. Results: We included 16 studies, comprising 465 patients aged 1-65 years. Moderate and conflicting evidence for low bone mineral density (Z-score ≤ -2.0) was found for several body parts (total proximal femur, total body, distal femur, lumbar spine) in children with Gross Motor Function Classification Scales II and III. We found no evidence for low bone mineral density in children with Gross Motor Function Classification Scale I or adults, although there was a tendency towards low bone mineral density (Z-score ≤ -1.0) for several body parts. Conclusions: Although more high-quality research is needed, results indicate that deficits in bone mineral density are not restricted to non-ambulatory people with cerebral palsy. Implications for Rehabilitation Although more high-quality research is needed, including adults and fracture risk assessment, the current study indicates that deficits in bone mineral density are not restricted to non-ambulatory people with CP. Health care professionals should be aware that optimal nutrition, supplements on indication, and an active lifestyle, preferably with weight-bearing activities, are important in ambulatory people with CP, also from a bone quality point-of-view. If indicated, medication and fall prevention training should be prescribed.