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Journal of Exercise Science and Fitness Oct 2023Enhancement in maximal oxygen consumption (VO) induced by hypoxic training is important for both athletes and non-athletes. However, the lack of comparison of multiple... (Review)
Review
BACKGROUND
Enhancement in maximal oxygen consumption (VO) induced by hypoxic training is important for both athletes and non-athletes. However, the lack of comparison of multiple paradigms and the exploration of related modulating factors leads to the inability to recommend the optimal regimen in different situations. This study aimed to investigate the efficacy of seven common hypoxic training paradigms on VO and associated moderators.
METHODS
Electronic (i.e., five databases) and manual searches were performed, and 42 studies involving 1246 healthy adults were included. Pairwise meta-analyses were conducted to compare different hypoxic training paradigms and hypoxic training and control conditions. The Bayesian network meta-analysis model was applied to calculate the standardised mean differences (SMDs) of pre-post VO alteration among hypoxic training paradigms in overall, athlete, and non-athlete populations, while meta-regression analyses were employed to explore the relationships between covariates and SMDs.
RESULTS
All seven hypoxic training paradigms were effective to varying degrees, with SMDs ranging from 1.45 to 7.10. Intermittent hypoxia interval training (IHIT) had the highest probability of being the most efficient hypoxic training paradigm in the overall population and athlete subgroup (42%, 44%), whereas intermittent hypoxic training (IHT) was the most promising hypoxic training paradigm among non-athletes (66%). Meta-regression analysis revealed that saturation hours (coefficient, 0.004; = 0.038; 95% CI [0.0002, 0.0085]) accounted for variations of VO improvement induced by IHT.
CONCLUSION
Efficient hypoxic training paradigms for VO gains differed between athletes and non-athletes, with IHIT ranking best for athletes and IHT for non-athletes. The practicability of saturation hours is confirmed with respect to dose-response issues in the future hypoxic training and associated scientific research.
REGISTRATION
This study was registered in the PROSPERO international prospective register of systematic reviews (CRD42022333548).
PubMed: 37854170
DOI: 10.1016/j.jesf.2023.09.001 -
Supportive Care in Cancer : Official... Oct 2023High-intensity interval training (HIIT) is an appropriate training modality to improve endurance and therefore contributes to physical performance. This review... (Meta-Analysis)
Meta-Analysis Review
Effects of high-intensity interval training on functional performance and maximal oxygen uptake in comparison with moderate intensity continuous training in cancer patients: a systematic review and meta-analysis.
INTRODUCTION
High-intensity interval training (HIIT) is an appropriate training modality to improve endurance and therefore contributes to physical performance. This review investigates the effect of HIIT on functional performance in cancer patients. We reviewed the relative peak oxygen uptake (relV̇O) and meta-analytical compared HIIT with moderate intensity continuous training (MICT). Furthermore, we took various training parameters under consideration.
METHODS
A systematic literature search was conducted in Scopus, PubMed, and Cochrane Library databases. For the review, we included randomized controlled trials containing HIIT with cancer patients. From this, we filtered interventions with additional MICT for the meta-analysis. Outcomes of interest were various functional performance assessments and V̇O.
RESULTS
The research yielded 584 records which fit the inclusion criteria, of which 31 studies with n=1555 patients (57.4±8.6 years) could be included in the overall review and 8 studies in the meta-analysis (n=268, 59.11±5.11 years) regarding relV̇O. Different functional outcomes were found, of which walking distance (+8.63±6.91% meters in 6-min walk test) and mobility (+2.7cm in sit and reach test) improved significantly due to HIIT. In terms of relV̇O, the performance of cancer patients was improved by HIIT (10.68±6.48%) and MICT (7.4±4.29%). HIIT can be favored to increase relV̇O (SMD 0.37; 95% CI 0.09-0.65; I=0%; p=0.009). Effect sizes for relV̇O improvements correlate moderately with total training volume (Spearman's ρ=0.49; p=0.03), whereas percentage increases do not (Spearman's ρ=0.24; p=0.14).
CONCLUSION
Functional and physical outcomes were positively altered by different HIIT protocols and forms of implementation, whereas a tendency toward more effectiveness of HIIT vs. MICT was found for relV̇O. Future studies should include functional parameters more often, to finally allow a comparison between both training protocols in this regard.
Topics: Humans; High-Intensity Interval Training; Oxygen Consumption; Nutritional Status; Physical Functional Performance; Oxygen; Neoplasms
PubMed: 37851104
DOI: 10.1007/s00520-023-08103-9 -
Sports Medicine (Auckland, N.Z.) Feb 2024Many sports require maximal strength and endurance performance. Concurrent strength and endurance training can lead to suboptimal training adaptations. However, how... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Many sports require maximal strength and endurance performance. Concurrent strength and endurance training can lead to suboptimal training adaptations. However, how adaptations differ between males and females is currently unknown. Additionally, current training status may affect training adaptations.
OBJECTIVE
We aimed to assess sex-specific differences in adaptations in strength, power, muscle hypertrophy, and maximal oxygen consumption ( O) to concurrent strength and endurance training in healthy adults. Second, we investigated how training adaptations are influenced by strength and endurance training status.
METHODS
A systematic review and meta-analysis was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, and a Cochrane risk of bias was evaluated. ISI Web of science, PubMed/MEDLINE, and SPORTDiscus databases were searched using the following inclusion criteria: healthy adults aged 18-50 years, intervention period of ≥ 4 weeks, and outcome measures were defined as upper- and lower-body strength, power, hypertrophy, and/or O. A meta-analysis was performed using a random-effects model and reported in standardized mean differences.
RESULTS
In total, 59 studies with 1346 participants were included. Concurrent training showed blunted lower-body strength adaptations in males, but not in females (male: - 0.43, 95% confidence interval [- 0.64 to - 0.22], female: 0.08 [- 0.34 to 0.49], group difference: P = 0.03). No sex differences were observed for changes in upper-body strength (P = 0.67), power (P = 0.37), or O (P = 0.13). Data on muscle hypertrophy were insufficient to draw any conclusions. For training status, untrained but not trained or highly trained endurance athletes displayed lower O gains with concurrent training (P = 0.04). For other outcomes, no differences were found between untrained and trained individuals, both for strength and endurance training status.
CONCLUSIONS
Concurrent training results in small interference for lower-body strength adaptations in males, but not in females. Untrained, but not trained or highly trained endurance athletes demonstrated impaired improvements in O following concurrent training. More studies on females and highly strength-trained and endurance-trained athletes are warranted.
CLINICAL TRIAL REGISTRATION
PROSPERO: CRD42022370894.
Topics: Adult; Humans; Male; Female; Endurance Training; Physical Endurance; Athletes; Sports; Hypertrophy; Muscle Strength; Resistance Training
PubMed: 37847373
DOI: 10.1007/s40279-023-01943-9 -
BMJ Open Respiratory Research Oct 2023Pectus excavatum (PEx) is the most common congenital chest wall abnormality affecting 1 in 400 births in the UK. PEx is associated with significant physiological and...
BACKGROUND
Pectus excavatum (PEx) is the most common congenital chest wall abnormality affecting 1 in 400 births in the UK. PEx is associated with significant physiological and psychological impairment. While readily surgically correctable, the benefits that surgery can bring have been debated and proven difficult to objectively measure. In the UK, this has led to the decommissioning of PEx surgery. The aim of this review is to conduct a systematic search of the literature on PEx surgery to assess physiological and psychological outcomes.
METHODS
A systematic review of the MEDLINE (PubMed), Embase and Cochrane databases was performed. Articles were sought which included patients undergoing surgery for PEx and reported on changes in cardiopulmonary measures, symptoms, quality of life and psychological assessments before and after surgical repair. Last search was performed in July 2022 and relevant findings were synthesised by narrative review.
RESULTS
Fifty-one articles were included in qualitative synthesis, with 34 studies relating to physiological outcomes and 17 studies relating to psychological and quality of life measures. Twenty-one studies investigated pulmonary function at rest. There was no change in forced vital capacity or forced expiratory volume in 1 second following open repair and transient reductions followed closed repair. In the 11 studies investigating echocardiography, transthoracic rarely demonstrated cardiac compression; however, transoesophageal demonstrated intraoperative relief in cardiac compression in severe cases. Sixteen studies investigated exercise testing (cardiopulmonary exercise testing, CPET), 12 of which demonstrated significant improvement following surgery, both in maximal oxygen consumption and oxygen pulse. Seventeen studies investigated quality of life, all but one of which showed improvement following repair of PEx. All papers that reported on patient satisfaction following surgery found high rates, between 80% and 97%.
DISCUSSION
While the majority of studies to date have been small and data heterogeneous, the literature shows that for many patients with PEx, there exists a cardiopulmonary limitation that while difficult to objectify, is likely to improve with surgical repair. Resting parameters offer little yield in aiding this except in the most severe cases. CPET therefore offers a better option for dynamic assessment of this limitation and improvements following repair. Surgery significantly improves psychological well-being and quality of life for patients with PEx.
Topics: Humans; Funnel Chest; Quality of Life; Lung; Vital Capacity; United Kingdom
PubMed: 37827806
DOI: 10.1136/bmjresp-2023-001665 -
PloS One 2023There is widespread agreement about the key role of hemoglobin for oxygen transport. Both observational and interventional studies have examined the relationship between... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
There is widespread agreement about the key role of hemoglobin for oxygen transport. Both observational and interventional studies have examined the relationship between hemoglobin levels and maximal oxygen uptake ([Formula: see text]) in humans. However, there exists considerable variability in the scientific literature regarding the potential relationship between hemoglobin and [Formula: see text]. Thus, we aimed to provide a comprehensive analysis of the diverse literature and examine the relationship between hemoglobin levels (hemoglobin concentration and mass) and [Formula: see text] (absolute and relative [Formula: see text]) among both observational and interventional studies.
METHODS
A systematic search was performed on December 6th, 2021. The study procedures and reporting of findings followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Article selection and data abstraction were performed in duplicate by two independent reviewers. Primary outcomes were hemoglobin levels and [Formula: see text] values (absolute and relative). For observational studies, meta-regression models were performed to examine the relationship between hemoglobin levels and [Formula: see text] values. For interventional studies, meta-analysis models were performed to determine the change in [Formula: see text] values (standard paired difference) associated with interventions designed to modify hemoglobin levels or [Formula: see text]. Meta-regression models were then performed to determine the relationship between a change in hemoglobin levels and the change in [Formula: see text] values.
RESULTS
Data from 384 studies (226 observational studies and 158 interventional studies) were examined. For observational data, there was a positive association between absolute [Formula: see text] and hemoglobin levels (hemoglobin concentration, hemoglobin mass, and hematocrit (P<0.001 for all)). Prespecified subgroup analyses demonstrated no apparent sex-related differences among these relationships. For interventional data, there was a positive association between the change of absolute [Formula: see text] (standard paired difference) and the change in hemoglobin levels (hemoglobin concentration (P<0.0001) and hemoglobin mass (P = 0.006)).
CONCLUSION
These findings suggest that [Formula: see text] values are closely associated with hemoglobin levels among both observational and interventional studies. Although our findings suggest a lack of sex differences in these relationships, there were limited studies incorporating females or stratifying results by biological sex.
Topics: Humans; Male; Female; Oxygen Consumption; Oxygen
PubMed: 37824583
DOI: 10.1371/journal.pone.0292835 -
Frontiers in Physiology 2023This study aimed to compare and rank the effect of hypoxic practices on maximum oxygen consumption (VOmax) in athletes and determine the hypoxic dose-response... (Review)
Review
This study aimed to compare and rank the effect of hypoxic practices on maximum oxygen consumption (VOmax) in athletes and determine the hypoxic dose-response correlation using network meta-analysis. The Web of Science, PubMed, EMBASE, and EBSCO databases were systematically search for randomized controlled trials on the effect of hypoxc interventions on the VOmax of athletes published from inception until 21 February 2023. Studies that used live-high train-high (LHTH), live-high train-low (LHTL), live-high, train-high/low (HHL), intermittent hypoxic training (IHT), and intermittent hypoxic exposure (IHE) interventions were primarily included. LHTL was further defined according to the type of hypoxic environment (natural and simulated) and the altitude of the training site (low altitude and sea level). A meta-analysis was conducted to determine the standardized mean difference between the effects of various hypoxic interventions on VOmax and dose-response correlation. Furthermore, the hypoxic dosage of the different interventions were coordinated using the "kilometer hour" model. From 2,072 originally identified titles, 59 studies were finally included in this study. After data pooling, LHTL, LHTH, and IHT outperformed normoxic training in improving the VOmax of athletes. According to the P-scores, LHTL combined with low altitude training was the most effective intervention for improving VOmax (natural: 0.92 and simulated: 0.86) and was better than LHTL combined with sea level training (0.56). A reasonable hypoxic dose range for LHTH (470-1,130 kmh) and HL (500-1,415 kmh) was reported with an inverted U-shaped curve relationship. Different types of hypoxic training compared with normoxic training serve as significant approaches for improving aerobic capacity in athletes. Regardless of the type of hypoxic training and the residential condition, LHTL with low altitude training was the most effective intervention. The characteristics of the dose-effect correlation of LHTH and LHTL may be associated with the negative effects of chronic hypoxia.
PubMed: 37745240
DOI: 10.3389/fphys.2023.1223037 -
Archives of Endocrinology and Metabolism Sep 2023To conduct a systematic review and meta-analysis assessing the cardiorespiratory fitness (CRF) among individuals with and without type 2 diabetes. (Meta-Analysis)
Meta-Analysis
OBJECTIVE
To conduct a systematic review and meta-analysis assessing the cardiorespiratory fitness (CRF) among individuals with and without type 2 diabetes.
MATERIALS AND METHODS
The current review was registered in PROSPERO under the number CRD42018082718. MEDLINE, EMBASE, and Cochrane Library databases were searched from inception through February 2022. Eligibility criteria consisted of observational or interventional studies that evaluated CRF through cardiopulmonary exercise testing or six-minute walk test in individuals with type 2 diabetes compared with individuals without type 2 diabetes. For data extraction, we used baseline CRF assessments of randomized clinical trials or follow-up CRF assessments in observational studies. We performed a meta-analysis using maximal oxygen consumption (VO max), and distance walked in the 6MWT as primary outcomes. They were extracted and expressed as mean differences (MDs) and 95% CIs between treatment and comparator groups. The meta-analysis was conducted using Review Manager (RevMan) software.
RESULTS
Out of 8,347 studies retrieved, 77 were included. Compared with individuals without type 2 diabetes, individuals with diabetes achieved a lower VO max (-5.84 mL.kg.min, 95% CI -6.93, -4.76 mL.kg.min, p = <0.0001; I = 91%, p for heterogeneity < 0.0001), and a smaller distance walked in 6MWT (-93.30 meters, 95% CI -141.2, -45.4 meters, p > 0.0001; I: 94%, p for heterogeneity < 0.0001).
CONCLUSION
Type 2 diabetes was associated with lower cardiorespiratory fitness, as observed by lower VO max on maximal tests, and smaller distance walked in 6MWT, however the quality of studies was low.
Topics: Humans; Diabetes Mellitus, Type 2; Cardiorespiratory Fitness; Exercise Test; Oxygen Consumption; Walk Test
PubMed: 37738467
DOI: 10.20945/2359-4292-2023-0040 -
PloS One 2023Aerobic capacity is a fitness measure reflecting the ability to sustain whole-body physical activity as fast and long as possible. Identifying the distribution of... (Comparative Study)
Comparative Study Meta-Analysis
Aerobic capacity is a fitness measure reflecting the ability to sustain whole-body physical activity as fast and long as possible. Identifying the distribution of aerobic capacity in a population may help estimate their health status. This study aimed to estimate standard values of aerobic capacity (peak oxygen uptake [Formula: see text] and anaerobic threshold [AT]/kg) for the Japanese population stratified by sex and age using a meta-analysis. Moreover, the comparison of the estimated standard values of the Japanese with those of other populations was performed as a supplementary analysis. We systematically searched original articles on aerobic capacity in the Japanese population using PubMed, Ichushi-Web, and Google Scholar. We meta-analysed [Formula: see text] (total: 78,714, men: 54,614, women: 24,100) and AT (total: 4,042, men: 1,961, women: 2,081) data of healthy Japanese from 21 articles by sex and age. We also searched, collected and meta-analysed data from other populations. Means and 95% confidence intervals were calculated. The estimated standard values of [Formula: see text] (mL/kg/min) for Japanese men and women aged 4-9, 10-19, 20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years were 47.6, 51.2, 43.2, 37.2, 34.5, 31.7, 28.6, and 26.3, and 42.0, 43.2, 33.6, 30.6, 27.4, 25.6, 23.4, and 23.1, respectively. The AT/kg (mL/kg/min) for Japanese men and women aged 20-29, 30-39, 40-49, 50-59, 60-69, and 70-79 years were 21.1, 18.3, 16.8, 15.9, 15.8, and 15.2, and 17.4, 17.0, 15.7, 15.0, 14.5, and 14.2, respectively. Herein, we presented the estimated standard values of aerobic capacity according to sex and age in a Japanese population. In conclusion, aerobic capacity declines with ageing after 20-29 years of age. Additionally, aerobic capacity is lower in the Japanese population than in other populations across a wide range of age groups. Standard value estimation by meta-analysis can be conducted in any country or region and for public health purposes.
Topics: Adult; Female; Humans; Male; Young Adult; Aging; Anaerobic Threshold; East Asian People; Exercise; Exercise Tolerance; Physical Fitness; Sex Factors; Age Factors; Japan; Oxygen Consumption; Child, Preschool; Child; Adolescent; Middle Aged; Aged
PubMed: 37713405
DOI: 10.1371/journal.pone.0286936 -
Sports Medicine (Auckland, N.Z.) Jan 2024It is important to consider biological sex as a variable that might influence exercise adaptation in order to optimize exercise prescription for men and women. (Meta-Analysis)
Meta-Analysis
Cardiorespiratory Fitness and Performance Adaptations to High-Intensity Interval Training: Are There Differences Between Men and Women? A Systematic Review with Meta-Analyses.
BACKGROUND
It is important to consider biological sex as a variable that might influence exercise adaptation in order to optimize exercise prescription for men and women.
OBJECTIVE
The aim of this study was to quantify the impact of biological sex on maximal oxygen uptake ([Formula: see text]O) and performance outcomes after high-intensity interval training (HIIT).
METHODS
A systematic search and review was conducted by two independent reviewers up to 8 September 2022 using MEDLINE, SPORTDiscus, and Sports Medicine & Education Index in ProQuest. Trials including healthy adults were included if they presented data for or compared male and female [Formula: see text]O or performance outcomes in response to HIIT. Performance outcomes included measures of exercise performance and concurrently measured physiological adaptations. Where appropriate, a random-effects, pre-post meta-analysis was undertaken. Data were sub-grouped for men and women, baseline training level, mean age, intervention type, and intervention length. Heterogeneity was assessed using Chi, Cochran's Q, and Higgins I and sensitivity analyses, where required. Study quality was assessed using the Newcastle-Ottawa Scale and publication bias was assessed through visual inspection of funnel plots.
RESULTS
Thirty-three references from 28 trials were included in the review (n = 965; 462 women and 503 men). Meta-analyses included 19 studies for [Formula: see text]O, eight for peak power output from [Formula: see text]O testing (PPO), and five for threshold power (power). Meta-analyses revealed similar increases in [Formula: see text]O in women (g = 0.57; 95% CI 0.44-0.69) and men (g = 0.57; 95% CI 0.42-0.72), and power in women (g = 0.38; 95% CI 0.13-0.64) and men (g = 0.38; 95% CI 0.11-0.64). Raw mean differences for change in [Formula: see text]O were Δ 0.32 L·min and 3.50 mL·kg·min in men, versus Δ 0.20 L·min and 3.34 mL·kg·min for women. No significant sex differences were present for the primary analysis of any outcome. After sub-grouping, significant differences were present for PPO where the effect size was higher for well-trained women (g = 0.37) compared with well-trained men (g = 0.17), and for [Formula: see text]O where interventions with a duration of 4 weeks or less had significantly smaller effect sizes compared with those longer than 4 weeks (p < 0.001). Unweighted mean percentage change in [Formula: see text]O, PPO, and power across studies was 11.16 ± 7.39%, 11.16 ± 5.99%, and 8.07 ± 6.55% for women, and 10.90 ± 5.75%, 8.22 ± 5.09%, and 7.09 ± 7.17% for men, respectively. Significant heterogeneity was present for both [Formula: see text]O and PPO (I, range: 62.06-78.80%). Sub-grouping by baseline training status and intervention length decreased heterogeneity in most groups. A qualitative synthesis of other outcomes indicated similar improvements in fitness and performance for men and women with some evidence suggesting differences in the mechanisms of adaptation.
LIMITATIONS AND RISK OF BIAS
Publication bias is unlikely to have significantly influenced results for [Formula: see text]O or power, but the meta-analysis of PPO could have benefitted from additional study data to strengthen results. The overlap in age categories and sensitivity of the analysis limits the accuracy of the results of the sub-grouping by age.
CONCLUSIONS
Findings indicated no sex-specific differences for any fitness or performance outcomes. Baseline training status and intervention length accounted for most variability in outcomes. PROSPERO registration number: CRD42021272615.
Topics: Adult; Female; Humans; Male; Cardiorespiratory Fitness; High-Intensity Interval Training; Oxygen Consumption
PubMed: 37676620
DOI: 10.1007/s40279-023-01914-0 -
Children (Basel, Switzerland) Aug 2023There is an association between very low birth weight (VLBW) and cardiovascular morbidity and mortality in adulthood. Aerobic fitness, measured as the maximal oxygen... (Review)
Review
There is an association between very low birth weight (VLBW) and cardiovascular morbidity and mortality in adulthood. Aerobic fitness, measured as the maximal oxygen consumption (VO max), is a good indicator of cardiopulmonary health and predictor of cardiovascular mortality. Our aim was to determine the effect of birth weight on aerobic exercise capacity and physical activity. We systematically identified studies reporting exercise capacity (VO max and VO peak) and physical activity levels in participants born at VLBW aged eighteen years or older compared to term-born controls from six databases (MEDLINE, OVID, EMBASE, CI NAHL, CENTRAL, and Google Scholar). Meta-analysis of eligible studies was conducted using a random effect model. We screened 6202 articles and identified 15 relevant studies, 10 of which were eligible for meta-analysis. VLBW participants had a lower VO max compared to their term counterparts (-3.35, 95% CI: -5.23 to -1.47, = 0.0005), as did VLBW adults who had developed bronchopulmonary dysplasia (-6.08, 95% CI -11.26 to -0.90, = 0.02). Five of nine studies reported significantly reduced self-reported physical activity levels. Our systematic review and meta-analysis demonstrated reduced maximal aerobic exercise capacity in adults born at VLBW compared to term-born controls.
PubMed: 37628426
DOI: 10.3390/children10081427