Effects of strict prolonged bed rest on cardiorespiratory fitness: systematic review and meta-analysis

2017 ◽  
Vol 123 (4) ◽  
pp. 790-799 ◽  
Author(s):  
Mathias Ried-Larsen ◽  
Hugo M. Aarts ◽  
Michael J. Joyner
Keyword(s):  
Systematic Review ◽  
Body Weight ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Cardiovascular Response ◽  
Meta Analysis ◽  
Bed Rest ◽  
Total Body Weight ◽  
Aerobic Exercise Training ◽  
Younger Women

The aim of this systematic review and meta-analysis [International Prospective Register of Systematic Reviews (PROSPERO) CRD42017055619] was to assess the effects of strict prolonged bed rest (without countermeasures) on maximal oxygen uptake (V̇o2max) and to explore sources of variation therein. Since 1949, 80 studies with a total of 949 participants (>90% men) have been published with data on strict bed rest and V̇o2max. The studies were conducted mainly in young participants [median age (interquartile range) 24.5 (22.4–34.0) yr]. The duration of bed rest ranged from 1 to 90 days. V̇o2max declined linearly across bed rest duration. No statistical difference in the decline among studies reporting V̇o2max as l/min (−0.3% per day) compared with studies reporting V̇o2max normalized to body weight (ml·kg−1·min−1; −0.43% per day) was observed. Although both total body weight and lean body mass declined in response to bed rest, we did not see any associations with the decline in V̇o2max. However, 15–26% of the variation in the decline in V̇o2max was explained by the pre-bed-rest V̇o2max levels, independent of the duration of bed rest (i.e., higher pre-bed-rest V̇o2max levels were associated with larger declines in V̇o2max). Furthermore, the systematic review revealed a gap in the knowledge about the cardiovascular response to extreme physical inactivity, particularly in older subjects and women of any age group. In addition to its relevance to spaceflight, this lack of data has significant translational implications because younger women sometimes undergo prolonged periods of bed rest associated with the complications of pregnancy and the incidence of hospitalization including prolonged periods of bed rest increases with age. NEW & NOTEWORTHY Large interindividual responses of maximal oxygen uptake (V̇o2max) to aerobic exercise training exist. However, less is known about the variability in the response of V̇o2max to prolonged bed rest. This systematic review and meta-analysis showed that pre-bed-rest V̇o2max values were inversely associated with the change in V̇o2max independent of the duration of bed rest. Moreover, we identified a large knowledge gap about the causes of decline in V̇o2max, particularly in postmenopausal women, which may have clinical implications.

scholarly journals A Systematic Review and Meta-Analysis of Submaximal Exercise-Based Equations to Predict Maximal Oxygen Uptake in Young People

2014 ◽  
Vol 26 (3) ◽  
pp. 342-357 ◽  
Author(s):  
Katia Ferrar ◽  
Harrison Evans ◽  
Ashleigh Smith ◽  
Gaynor Parfitt ◽  
Roger Eston
Keyword(s):  
Systematic Review ◽  
Young People ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Meta Analysis ◽  
Submaximal Exercise ◽  
Gas Analysis ◽  
Exercise Tests ◽  
Exercise Mode ◽  
Selection Of

Many equations to predict maximal oxygen uptake (V̇O2max) from submaximal exercise tests have been proposed for young people, but the composition and accuracy of these equations vary greatly. The purpose of this systematic review was to analyze all submaximal exercise-based equations to predict V̇O2max measured via direct gas analysis for use with young people. Five databases were systematically searched in February 2013. Studies were included if they used a submaximal, exercise-based method to predict V̇O2max; the actual V̇O2max was gas analyzed; participants were younger than 18 years; and equations included at least one submaximal exercise-based variable. A meta-analysis and narrative synthesis were conducted. Sixteen studies were included. The mean equation validity statistic was strong, r = .786 (95% CI 0.747–0.819). Subgroup meta-analysis suggests exercise mode may contribute to the overall model, with running- and walking-based predictive equations reporting the highest mean r values (running r = .880; walking r = .821) and cycling the weakest (r = .743). Selection of the most appropriate equation should be guided by factors such as purpose, logistic limitations, appropriateness of the validation sample, the level of study bias, and the degree of accuracy. Suggestions regarding the most accurate equation for each exercise mode are provided.

scholarly journals Is a verification phase useful for confirming maximal oxygen uptake in apparently healthy adults? A systematic review and meta-analysis

PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0247057
Author(s):  
Victor A. B. Costa ◽  
Adrian W. Midgley ◽  
Sean Carroll ◽  
Todd A. Astorino ◽  
Tainah de Paula ◽  
...  
Keyword(s):  
Systematic Review ◽  
Oxygen Uptake ◽  
Cardiorespiratory Fitness ◽  
Maximal Oxygen Uptake ◽  
Meta Analysis ◽  
Healthy Adults ◽  
Phase Duration ◽  
Funnel Plot ◽  
Exercise Modality ◽  
Apparently Healthy

Background The ‘verification phase’ has emerged as a supplementary procedure to traditional maximal oxygen uptake (VO2max) criteria to confirm that the highest possible VO2 has been attained during a cardiopulmonary exercise test (CPET). Objective To compare the highest VO2 responses observed in different verification phase procedures with their preceding CPET for confirmation that VO2max was likely attained. Methods MEDLINE (accessed through PubMed), Web of Science, SPORTDiscus, and Cochrane (accessed through Wiley) were searched for relevant studies that involved apparently healthy adults, VO2max determination by indirect calorimetry, and a CPET on a cycle ergometer or treadmill that incorporated an appended verification phase. RevMan 5.3 software was used to analyze the pooled effect of the CPET and verification phase on the highest mean VO2. Meta-analysis effect size calculations incorporated random-effects assumptions due to the diversity of experimental protocols employed. I2 was calculated to determine the heterogeneity of VO2 responses, and a funnel plot was used to check the risk of bias, within the mean VO2 responses from the primary studies. Subgroup analyses were used to test the moderator effects of sex, cardiorespiratory fitness, exercise modality, CPET protocol, and verification phase protocol. Results Eighty studies were included in the systematic review (total sample of 1,680 participants; 473 women; age 19–68 yr.; VO2max 3.3 ± 1.4 L/min or 46.9 ± 12.1 mL·kg-1·min-1). The highest mean VO2 values attained in the CPET and verification phase were similar in the 54 studies that were meta-analyzed (mean difference = 0.03 [95% CI = -0.01 to 0.06] L/min, P = 0.15). Furthermore, the difference between the CPET and verification phase was not affected by any of the potential moderators such as verification phase intensity (P = 0.11), type of recovery utilized (P = 0.36), VO2max verification criterion adoption (P = 0.29), same or alternate day verification procedure (P = 0.21), verification-phase duration (P = 0.35), or even according to sex, cardiorespiratory fitness level, exercise modality, and CPET protocol (P = 0.18 to P = 0.71). The funnel plot indicated that there was no significant publication bias. Conclusions The verification phase seems a robust procedure to confirm that the highest possible VO2 has been attained during a ramp or continuous step-incremented CPET. However, given the high concordance between the highest mean VO2 achieved in the CPET and verification phase, findings from the current study would question its necessity in all testing circumstances. PROSPERO Registration ID CRD42019123540.

scholarly journals The effect of L‐arginine supplementation on maximal oxygen uptake: A systematic review and meta‐analysis

2021 ◽  
Vol 9 (3) ◽  
Author(s):  
Shahla Rezaei ◽  
Maryam Gholamalizadeh ◽  
Reza Tabrizi ◽  
Peyman Nowrouzi‐Sohrabi ◽  
Samira Rastgoo ◽  
...  
Keyword(s):  
Systematic Review ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Meta Analysis ◽  
Arginine Supplementation

scholarly journals Size Exponents for Scaling Maximal Oxygen Uptake in Over 6500 Humans: A Systematic Review and Meta-Analysis

2017 ◽  
Vol 47 (7) ◽  
pp. 1405-1419 ◽  
Author(s):  
Lorenzo Lolli ◽  
Alan M. Batterham ◽  
Kathryn L. Weston ◽  
Greg Atkinson
Keyword(s):  
Systematic Review ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Meta Analysis

scholarly journals Effects of a Low-Carbohydrate High-Fat Diet Combined with High-Intensity Interval Training on Body Composition and Maximal Oxygen Uptake: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 18 (20) ◽  
pp. 10740
Author(s):  
Jing Hu ◽  
Zhen Wang ◽  
Bingkai Lei ◽  
Junping Li ◽  
Ruiyuan Wang
Keyword(s):  
Systematic Review ◽  
Body Composition ◽  
Oxygen Uptake ◽  
Maximal Oxygen Uptake ◽  
Meta Analysis ◽  
Interval Training ◽  
High Intensity Interval Training ◽  
High Fat ◽  
Low Carbohydrate ◽  
High Intensity Interval

The low-carbohydrate high-fat (LCHF) diet has recently been subject to attention on account of its reported influences on body composition and physical performance. However, the combined effect of LCHF with high-intensity interval training (HIIT) is unclear. A systematic review and meta-analysis were conducted to explore the effect of the LCHF diet combined with HIIT on human body composition (i.e., body weight (BM), body mass index (BMI), fat mass (FM), body fat percentage (BFP), fat-free mass (FFM)) and maximal oxygen uptake (VO2max). Online libraries (PubMed, Web of Science, EMBASE, Cochrane Library, EBSCO, CNKI, Wan Fang) were used to search initial studies until July 2021, from which 10 out of 2440 studies were included. WMD served as the effect size with a confidence interval value of 95%. The results of meta-analysis showed a significant reduction in BM (WMD = −5.299; 95% CI: −7.223, −3.376, p = 0.000), BMI (WMD = −1.150; 95% CI: −2.225, −0.075, p = 0.036), BFP (WMD = −2.787; 95% CI: −4.738, −0.835, p = 0.005) and a significant increase in VO2max (WMD = 3.311; 95% CI: 1.705, 4.918, p = 0.000), while FM (WMD = −2.221; 95% CI: −4.582, 0.139, p = 0.065) and FFM (WMD = 0.487; 95% CI: −3.512, 4.469, p = 0.814) remained unchanged. In conclusion, the LCHF diet combined with HIIT can reduce weight and fat effectively. This combination is sufficient to prevent muscle mass loss during LCHF, and further enhance VO2max. Further research might be required to clarify the effect of other types of exercise on body composition and physical performance during LCHF.

Effects of diacerein intake on cardiometabolic profiles in type 2 diabetics: a systematic review and meta-analysis of clinical trials.

2020 ◽  
Vol 27 ◽  
Author(s):  
Peyman Nowrouzi-Sohrabi ◽  
Reza Tabrizi ◽  
Mohammad Jalali ◽  
Navid Jamali ◽  
Shahla Rezaei ◽  
...  
Keyword(s):  
Systematic Review ◽  
Clinical Trials ◽  
Body Weight ◽  
Total Cholesterol ◽  
Ldl Cholesterol ◽  
Meta Analysis ◽  
Hdl Cholesterol ◽  
Cochrane Central Register ◽  
Statistical Heterogeneity

Introduction: A systematic review and meta-analysis of clinical trials was undertaken to evaluate the effect of diacerein intake on cardiometabolic profiles in patients with type 2 diabetes mellitus (T2DM). Methods: Electronic databases such as PubMed, EMBASE, Scopus, Web of Science, Google Scholar, and Cochrane Central Register of Controlled Trials were searched from inception to 31 July 2019. Statistical heterogeneity was evaluated using Cochran’s Q test and I-square (I2 ) statistic. Data were pooled using random-effect models and weighted mean difference (WMD). Results: From 1,733 citations, seven clinical trials were eligible for inclusion and meta-analysis. A significant reduction in hemoglobin A1c (HbA1c) (WMD -0.73; 95%CI -1.25 to -0.21; P= 0.006; I2 = 72.2%) and body mass index (BMI) (WMD -0.55; 95%CI -1.03 to -0.07; P= 0.026; I2 = 9.5%) were identified. However, no significant effect of diacerein intake was identified on fasting blood sugar (FBS) (WMD - 9.00; 95%CI -22.57 to 4.57; P= 0.194; I2 = 60.5%), homeostatic model assessment for insulin resistance (HOMA-IR) (WMD 0.39; 95%CI 0.95 to 1.73; P= 0.569; I2 = 2.2%), body weight (WMD -0.54; 95%CI -1.10 to 0.02; P= 0.059), triglycerides (WMD -0.56; 95%CI -24.16 to 23.03; P= 0.963; I2 = 0.0%), total-cholesterol (WMD -0.21; 95%CI -12.19 to 11.78; P= 0.973; I2 = 0.0%), HDL-cholesterol (WMD -0.96; 95%CI -2.85 to 0.93; P= 0.321; I2 = 0.0%), and LDL-cholesterol levels (WMD -0.09; 95%CI -8.43 to 8.25; P= 0.983; I2 = 37.8%). Conclusion: Diacerein intake may reduce HbA1c and BMI; however, no evidence of effect was observed for FBS, HOMA-IR, body weight, triglycerides, total-cholesterol, HDL-cholesterol or LDL-cholesterol.

scholarly journals Hair Loss After Metabolic and Bariatric Surgery: a Systematic Review and Meta-analysis

2021 ◽  
Author(s):  
Wen Zhang ◽  
◽  
Meiling Fan ◽  
Cunchuan Wang ◽  
Kamal Mahawar ◽  
...  
Keyword(s):  
Systematic Review ◽  
Bariatric Surgery ◽  
Folic Acid ◽  
Hair Loss ◽  
Meta Analysis ◽  
Serum Zinc ◽  
Serum Levels ◽  
Mean Difference ◽  
Younger Women ◽  
Metabolic And Bariatric Surgery

Abstract Background Hair loss is a common complication after metabolic and bariatric surgery (MBS). There is a lack of published systematic review in the scientific literature on this topic. The aim of this study was to perform a systematic review and meta-analysis on hair loss after MBS in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) guidelines. Methods PubMed, CINAHL, EMBASE, Web of Science, SCOPUS, and four Chinese databases were searched. Data were pooled using Review Manager 5.3 and Stata 12.0, and subgroups were performed if necessary and feasible. Results A total of 18 studies (n = 2538) were included. The pooled results showed that the incidence of hair loss after MBS was 57% (95% CI 42–71%). It decreased with longer follow-up times. Hair loss was significantly more common in younger (mean difference (MD), − 2.45; 95% CI, − 4.26 to − 0.64; p = 0.008) women (OR, 3.87; 95% CI, 0.59 to 17.59; p = 0.08). Serum zinc (standardized mean difference (SMD), − 1.13; 95% CI, − 2.27 to 0.01, p = 0.05), folic acid (SMD = − 0.88, 95% CI − 1.29 to − 0.46, p < 0.0001), and ferritin levels (SMD, − 0.22; 95% CI, − 0.38 to − 0.05; p = 0.01), but not serum iron and vitamin B12, were associated with hair loss following MBS. Conclusions Hair loss is common after MBS especially in younger women, and those with low serum levels of zinc, folic acid, and ferritin. Prospective studies on larger cohorts are needed.

scholarly journals Effectiveness of Oral Nutritional Supplements on Older People with Anorexia: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 835
Author(s):  
Mengqi Li ◽  
Si Zhao ◽  
Shuang Wu ◽  
Xiufen Yang ◽  
Hui Feng
Keyword(s):  
Systematic Review ◽  
Body Weight ◽  
Older People ◽  
Energy Intake ◽  
Meta Analysis ◽  
Nutritional Supplements ◽  
The Elderly ◽  
Randomized Controlled ◽  
Oral Nutritional Supplements ◽  
Positive Effect

Background: Nutrition plays an important role in maintaining the overall health of older people. Inadequate intake may lead to impaired body function, higher morbidity, and mortality. Oral nutritional supplements (ONS) showed positive effect on the nutritional status of the elderly; however, systematic evidence is currently lacking on the effect of ONS on the elderly with anorexia. Aims: The current systematic review and meta-analysis included randomized controlled trial (RCT) articles to investigate the effectiveness of ONS on the main aspects of anorexia of aging (AA). Methods: By using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method, researchers independently searched PubMed/MEDLINE, EMBASE, CINAHL, PsycINFO, the Cochrane Library, China National Knowledge Infrastructure (CNKI) and other gray literature resources for publications that met the inclusion criteria by October 2020. The Cochrane Risk of Bias Tools were used for quality assessment. The inverse-variance method was used for the fixed model (FM) while the DerSimonian–Laird method was used for the random model (RM). Respective 95% confidence intervals (95% CIs), mean difference (MD) or standardized mean difference (SMD) was used for indices in terms of effect size (ES). Results: 2497 records were found through the systematic search, while 17 RCTs (n = 1204) were included, with a mean age of 81.9 years (range: 74–87 years). Supplementation occurred in the morning, mid-day, and evening, while the times varied from one to three times a day. The results of meta-analysis showed that, generally, ONS had a positive effect on the overall appetite, MD = 0.18, 95% CI (0.03, 0.33), p = 0.02, and consumption, MD = 1.43, 95% CI (0.01, 2.86), p = 0.05; but not significant in terms of other aspects of appetite: hunger, p = 0.73; fullness, p = 0.60; desire to eat, p = 0.80; preoccupation, p = 0.15. Additionally, it showed an increase in the overall energy intake, SMD = 0.46, 95% CI (0.29, 0.63), p < 0.001, in protein intake, SMD = 0.59, 95% CI (0.16, 1.02), p = 0.007, and in fat intake, MD = 3.47, 95% CI (1.98, 4.97), p < 0.001, while no positive effect was found on carbohydrates intake, p = 0.06. Significance differences were also found in the body weight, SMD = 0.53, 95% CI (0.41, 0.65), p < 0.001, and body mass index (BMI), MD = 0.53, 95% CI (0.12, 0.95), p = 0.01. Moreover, subgroup analyses were conducted according to the nutrient density with no positive results showed except for the low-density ONS on overall energy intake. Conclusions: The results of the present study indicated that ONS had beneficial effects on overall appetite, energy intake, body weight and BMI.

What Types of Exercise Are More Effective in Reducing Obesity and Blood Pressure for Middle-Aged Women? A Systematic Review With Meta-Analysis

2021 ◽  
pp. 109980042110154
Author(s):  
Seong-Hi Park ◽  
Chul-Gyu Kim
Keyword(s):  
Systematic Review ◽  
Blood Pressure ◽  
Metabolic Syndrome ◽  
Body Weight ◽  
Waist Circumference ◽  
Meta Analysis ◽  
Physical Activities ◽  
Risk Of Bias ◽  
Cochrane Library ◽  
Middle Aged

Background: A systematic review was performed to identify the types of physical activities effective as interventions in preventing metabolic syndrome in middle-aged women. Methods: Electronic databases (MEDLINE, EMBASE, the Cochrane Library, and CINAHL) served as the data sources. Cochrane’s Risk of Bias 2 was applied to assess the risk of bias of the randomized controlled trials. Meta-analyses were performed on selected studies using Review Manager 5.3. Thirty-one trials enrolling 2,202 participants were included. Results: Compared to controls, the effects of physical activity were indicated by pooled mean differences, which were −0.57 kg for body weight, −0.43 kg/m2 for body mass index, −1.63 cm for waist circumference, −4.89 mmHg for systolic blood pressure (BP), and −2.71 mmHg for diastolic BP. The effects were greater on the measurements of waist circumference and BP than on body weight and BMI. The types of physical activities were further analyzed according to sub-groups. Only aerobic exercise did not affect body weight and resistance exercise did not significantly change any results. Contrarily, combined exercises significantly reduced measurements of waist circumference and BP. Conclusion: This review can provide valuable information for research and implementation of measures to prevent metabolic syndrome in middle-aged women.

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