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International Journal of Environmental... Mar 2023Strength training in prepubertal children is one of the topics that has aroused the most interest and controversy among training professionals in recent years.... (Review)
Review
Strength training in prepubertal children is one of the topics that has aroused the most interest and controversy among training professionals in recent years. Therefore, the aim of the present study was to analyze the available scientific evidence on the influence of strength training variables on morphological and/or neuromuscular adaptations in healthy prepubertal populations with no previous experience in this type of training according to the descriptive sample characteristics. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis, 22 studies were selected after a systematic search and selection process using four electronic databases: Google Scholar, PubMed, Scopus, and SPORT Discus. Furthermore, the internal validity of the studies included was assessed using the modified PEDro scale. The sample consisted of 604 prepubertal children (age, 10.02 ± 0.75 years), of whom 473 were boys and 131 were girls, with 104 strength training programs recorded. Strength training resulted in a significant increase in jumping ( = 29) and sprinting ( = 13) abilities. Moreover, muscle strength was increased in 100% of the cases. Morphologically, strength training resulted in a decrease in body fat percentage ( = 19) and an increase in lean body mass ( = 17). With regard to gender, increases in general sport skills and basic physical abilities were significant in males but not in females. Thus, the results are more heterogeneous in girls due to the small number of studies carried out. Therefore, this research provides practical applications for coaches to design and implement more effective training programs to maximize adaptations, enhance physical performance, and reduce injury risk.
Topics: Male; Female; Humans; Child; Resistance Training; Muscle Strength; Sports; Adaptation, Physiological; Acclimatization
PubMed: 36981742
DOI: 10.3390/ijerph20064833 -
Sports Medicine (Auckland, N.Z.) Sep 2023Augmented feedback is often used during resistance training to enhance acute physical performance and has shown promise as a method of improving chronic physical... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Augmented feedback is often used during resistance training to enhance acute physical performance and has shown promise as a method of improving chronic physical adaptation. However, there are inconsistencies in the scientific literature regarding the magnitude of the acute and chronic responses to feedback and the optimal method with which it is provided.
OBJECTIVE
This systematic review and meta-analysis aimed to (1) establish the evidence for the effects of feedback on acute resistance training performance and chronic training adaptations; (2) quantify the effects of feedback on acute kinematic outcomes and changes in physical adaptations; and (3) assess the effects of moderating factors on the influence of feedback during resistance training.
METHODS
Twenty studies were included in this systematic review and meta-analysis. This review was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Four databases were searched, and studies were included if they were peer-reviewed investigations, written in English, and involved the provision of feedback during or following dynamic resistance exercise. Furthermore, studies must have evaluated either acute training performance or chronic physical adaptations. Risk of bias was assessed using a modified Downs and Black assessment tool. Multilevel meta-analyses were performed to quantify the effects of feedback on acute and chronic training outcomes.
RESULTS
Feedback enhanced acute kinetic and kinematic outputs, muscular endurance, motivation, competitiveness, and perceived effort, while greater improvements in speed, strength, jump performance, and technical competency were reported when feedback was provided chronically. Furthermore, greater frequencies of feedback (e.g., following every repetition) were found to be most beneficial for enhancing acute performance. Results demonstrated that feedback improves acute barbell velocities by approximately 8.4% (g = 0.63, 95% confidence interval [CI] 0.36-0.90). Moderator analysis revealed that both verbal (g = 0.47, 95% CI 0.22-0.71) and visual feedback (g = 1.11, 95% CI 0.61-1.61) were superior to no feedback, but visual feedback was superior to verbal feedback. For chronic outcomes, jump performance might have been positively influenced (g = 0.39, 95% CI - 0.20 to 0.99) and short sprint performance was likely enhanced (g = 0.47, 95% CI 0.10-0.84) to a greater extent when feedback is provided throughout a training cycle.
CONCLUSIONS
Feedback during resistance training can lead to enhanced acute performance within a training session and greater chronic adaptations. Studies included in our analysis demonstrated a positive influence of feedback, with all outcomes showing superior results than when no feedback is provided. For practitioners, it is recommended that high-frequency, visual feedback is consistently provided to individuals when they complete resistance training, and this may be particularly useful during periods of low motivation or when greater competitiveness is beneficial. Alternatively, researchers must be aware of the ergogenic effects of feedback on acute and chronic responses and ensure that feedback is standardised when investigating resistance training.
Topics: Humans; Resistance Training; Muscle Strength; Exercise; Adaptation, Physiological; Acclimatization
PubMed: 37410360
DOI: 10.1007/s40279-023-01877-2 -
Sports Medicine (Auckland, N.Z.) Feb 2018Although the acquisition of heat acclimation (HA) is well-documented, less is known about HA decay (HAD) and heat re-acclimation (HRA). The available literature suggests... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Although the acquisition of heat acclimation (HA) is well-documented, less is known about HA decay (HAD) and heat re-acclimation (HRA). The available literature suggests 1 day of HA is lost following 2 days of HAD. Understanding this relationship has the potential to impact upon the manner in which athletes prepare for major competitions, as a HA regimen may be disruptive during final preparations (i.e., taper).
OBJECTIVE
The aim of this systematic review and meta-analysis was to determine the rate of HAD and HRA in three of the main physiological adaptations occurring during HA: heart rate (HR), core temperature (T ), and sweat rate (SR).
DATA SOURCES
Data for this systematic review were retrieved from Scopus and critical review of the cited references.
STUDY SELECTION
Studies were included when they met the following criteria: HA, HAD, and HRA (when available) were quantified in terms of exposure and duration. HA had to be for at least 5 days and HAD for at least 7 days for longitudinal studies. HR, T , or SR had to be monitored in human participants.
STUDY APPRAISAL
The level of bias in each study was assessed using the McMaster critical review form. Multiple linear regression techniques were used to determine the dependency of HAD in HR, T , and SR from the number of HA and HAD days, daily HA exposure duration, and intensity.
RESULTS
Twelve studies met the criteria and were systematically reviewed. HAD was quantified as a percentage change relative to HA (0% = HA, 100% = unacclimated state). Adaptations in end-exercise HR decreased by 2.3% (P < 0.001) for every day of HAD. For end-exercise T , the daily decrease was 2.6% (P < 0.01). The adaptations in T during the HA period were more sustainable when the daily heat exposure duration was increased and heat exposure intensity decreased. The decay in SR was not related to the number of decay days. However, protracted HA-regimens seem to induce longer-lasting adaptations in SR. High heat exposure intensities during HA seem to evoke more sustained adaptations in SR than lower heat stress. Only eight studies investigated HRA. HRA was 8-12 times faster than HAD at inducing adaptations in HR and T , but no differences could be established for SR.
LIMITATIONS
The available studies lacked standardization in the protocols for HA and HAD.
CONCLUSIONS
HAD and HRA differ considerably between physiological systems. Five or more HA days are sufficient to cause adaptations in HR and T ; however, extending the daily heat exposure duration enhances T adaptations. For every decay day, ~ 2.5% of the adaptations in HR and T are lost. For SR, longer HA periods are related to better adaptations. High heat exposure intensities seem beneficial for adaptations in SR, but not in T . HRA induces adaptations in HR and T at a faster rate than HA. HRA may thus provide a practical and less disruptive means of maintaining and optimizing HA prior to competition.
Topics: Acclimatization; Body Temperature Regulation; Cross-Sectional Studies; Exercise; Heart Rate; Heat Stress Disorders; Hot Temperature; Humans; Male; Oxygen Consumption; Physical Exertion
PubMed: 29129022
DOI: 10.1007/s40279-017-0808-x -
Undersea & Hyperbaric Medicine :... 2021Multiday hyperbaric exposure has been shown to reduce the incidence of decompression sickness (DCS) of compressed-air workers. This effect, termed acclimatization, has...
Multiday hyperbaric exposure has been shown to reduce the incidence of decompression sickness (DCS) of compressed-air workers. This effect, termed acclimatization, has been addressed in a number of studies, but no comprehensive review has been published. This systematic review reports the findings of a literature search. PubMed, Ovid Embase, The Cochrane Library and Rubicon Research Repository were searched for studies reporting DCS incidence, venous gas embolism (VGE) or subjective health reports after multiday hyperbaric exposure in man and experimental animals. Twenty-nine studies fulfilled inclusion criteria. Three epidemiological studies reported statistically significant acclimatization to DCS in compressed-air workers after multiday hyperbaric exposure. One experimental study observed less itching after standardized simulated dives. Two human experimental studies reported lower DCS incidence after multiday immersed diving. Acclimatization to DCS has been observed in six animal species. Multiday diving had less consistent effect on VGE after hyperbaric exposure in man. Four studies observed acclimatization while no statistically significant acclimatization was reported in the remaining eight studies. A questionnaire study did not report any change in self-perceived health after multiday diving. This systematic review has not identified any study suggesting a sensitizing effect of multiday diving, and there is a lack of data supporting benefit of a day off diving after a certain number of consecutive diving days. The results suggest that multiday hyperbaric exposure probably will have an acclimatizing effect and protects from DCS. The mechanisms causing acclimatization, extent of protection and optimal procedure for acclimatization has been insufficiently investigated.
Topics: Animals; Cats; Dogs; Humans; Rabbits; Rats; Acclimatization; Atmospheric Pressure; Decompression Sickness; Diagnostic Self Evaluation; Diving; Embolism, Air; Goats; Hyperbaric Oxygenation; Incidence; Occupational Diseases; Rats, Sprague-Dawley; Reference Values; Time Factors
PubMed: 33975403
DOI: 10.22462/03.04.2021.3 -
Sports Medicine (Auckland, N.Z.) Mar 2023Isotonic exercise is the most common mode of strength training. Isotonic strength is often measured in the movement that was exercised, but isometric and isokinetic... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Isotonic exercise is the most common mode of strength training. Isotonic strength is often measured in the movement that was exercised, but isometric and isokinetic movements are also commonly used to quantify changes in muscular strength. Previous research suggests that increasing strength in one movement may not lead to an increase in strength in a different movement. Quantifying the increase in strength in a movement not trained may be important for understanding strength training adaptations and making recommendations for resistance exercise and rehabilitation programs.
OBJECTIVE
To quantify changes in non-specific strength relative to a control.
DESIGN
A systematic review and random effects meta-analysis was conducted investigating the effects of isotonic strength training on isotonic and isokinetic/isometric strength.
SEARCH AND INCLUSION
This systematic review was conducted in Google scholar, PubMed, Academic Search Premier, and MENDELEY. To be included in this review paper the article needed to meet the following criteria: (1) report sufficient data for our variables of interest (i.e., changes in isotonic strength and changes in isokinetic or isometric strength); (2) include a time-matched non-exercise control; (3) be written in English; (4) include healthy human participants over the age of 18 years; (5) the participants had to train and test isotonically; (6) the participants had to be tested isokinetically or isometrically on a device different from that they trained on; (7) the non-specific strength task had to test a muscle involved in the training (i.e., could not have trained chest press and test handgrip strength); and (8) the control group and the experimental group had to perform the same number of strength tests.
RESULTS
We completed two separate searches. In the original search a total of 880 papers were screened and nine papers met the inclusion criteria. In the secondary search a total of 2594 papers were screened and three additional papers were added (total of 12 studies). The overall effect of resistance training on changes in strength within a movement that was not directly trained was 0.8 (Cohen's d) with a standard error of 0.286. This overall effect was significant (t = 2.821, p = 0.01) and the 95% confidence interval (CI) is 0.22-1.4. The overall effect of resistance training on strength changes within a movement that was directly trained was 1.84 (Cohen's d) with a standard error of 0.296. This overall effect was significant (t = 6.221, p < 0.001) and the 95% CI is 1.23-2.4.
CONCLUSION
The results of our meta-analysis suggest that strength increases in both the specific and non-specific strength tests. However, the smaller effect size associated with non-specific strength suggests that it will be difficult for a single study to meaningfully investigate the transfer of strength training adaptions.
Topics: Humans; Adult; Middle Aged; Hand Strength; Muscle, Skeletal; Muscle Strength; Adaptation, Physiological; Acclimatization; Resistance Training
PubMed: 36396899
DOI: 10.1007/s40279-022-01790-0 -
Physiological Reports Jun 2023Physiological properties and function of the lymphatic system is still somewhat of a mystery. We report the current knowledge about human lymphatic vessel contractility... (Review)
Review
Physiological properties and function of the lymphatic system is still somewhat of a mystery. We report the current knowledge about human lymphatic vessel contractility and capability of adaptation. A literature search in PubMed identified studies published January 2000-September 2022. Inclusion criteria were studies investigating parameters related to contraction frequency, fluid velocity, and lymphatic pressure in vivo and ex vivo in human lymphatic vessels. The search returned 2885 papers of which 28 met the inclusion criteria. In vivo vessels revealed baseline contraction frequencies between 0.2 ± 0.2 and 1.8 ± 0.1 min , velocities between 0.008 ± 0.002 and 2.3 ± 0.3 cm/s, and pressures between 4.5 (range 0.5-9.2) and 60.3 ± 2.8 mm Hg. Gravitational forces, hyperthermia, and treatment with nifedipine caused increases in contraction frequency. Ex vivo lymphatic vessels displayed contraction frequencies between 1.2 ± 0.1 and 5.5 ± 1.2 min . Exposure to agents affecting cation and anion channels, adrenoceptors, HCN channels, and changes in diameter-tension properties all resulted in changes in functional parameters as known from the blood vascular system. We find that the lymphatic system is dynamic and adaptable. Different investigative methods yields alternating results. Systematic approaches, consensus on investigative methods, and larger studies are needed to fully understand lymphatic transport and apply this in a clinical context.
Topics: Humans; Lymphatic System; Lymphatic Vessels; Adaptation, Physiological; Acclimatization
PubMed: 37269161
DOI: 10.14814/phy2.15697 -
Philosophical Transactions of the Royal... Jul 2022Vulnerable locations, such as coastlines, are at a high risk of loss and damage. Such places will suffer deleterious impacts as climate change impacts are increasingly... (Review)
Review
Vulnerable locations, such as coastlines, are at a high risk of loss and damage. Such places will suffer deleterious impacts as climate change impacts are increasingly realized. As societies try to adapt to these impacts, managed or planned retreat-aimed at moving people and assets away from vulnerable locations-is gaining increased attention. Despite this increased attention, systematic literature reviews of the retreat literature remain scarce. This paper undertakes such review and uncovers a marked increase in retreat scholarly research papers in the past 5 years. An analysis of 135 managed and planned retreat journal articles is completed. Findings include a strong emphasis on regional or local case studies exploring governance, policy or institutional settings and levers across a range of geographies. Property rights and market interventions, such as compensation schemes, evidence the prevalence of neoliberal predilections. This emphasizes the importance of renewed engagement with political economy scholarship vis-à-vis climate change adaptation, also supported by the sharp increase in the evidenced social and environmental justice impacts. This article is part of the theme issue 'Nurturing resilient marine ecosystems'.
Topics: Acclimatization; Adaptation, Physiological; Climate Change; Ecosystem; Humans
PubMed: 35574844
DOI: 10.1098/rstb.2021.0129 -
Journal of Thermal Biology Aug 2023Given the increasing trend of global warming and extreme weather conditions, including heat waves and its effects on health, the present study was done to investigate... (Review)
Review
BACKGROUND
Given the increasing trend of global warming and extreme weather conditions, including heat waves and its effects on health, the present study was done to investigate adaptive behaviors of communities in the world for combating heat waves.
METHOD
ology: In this systematic review, out of 1529 results, 57 relevant and authoritative English papers on adaptation to heat waves hazard were extracted and evaluated using valid keywords from valid databases (PubMed, WOS, EMBASE, and Scopus). In addition, multiple screening steps were done and then, the selected papers were qualitatively assessed. Evaluation results were summarized using an Extraction Table.
RESULTS
In this paper, the adaptive behaviors for combating heat waves hazard were summarized into 11 categories: Education and awareness raising, Adaptation of critical infrastructure, Governments measures, Health-related measures, Application of early warning system, Protective behaviors in workplace, Physical condition, Adaptive individual behaviors, Design and architecture of the building, Green infrastructure (green cover), and Urban design.
CONCLUSION
The findings of this study showed that community actions have significant effects on adaptation to heat wave. Therefore, for reducing heat wave-related negative health effects and vulnerability, more attention should be paid to the above-mentioned actions for mitigation, preparation, and responding regarding heat waves.
PROSPERO REGISTRATION NUMBER
CRD42021257747.
Topics: Hot Temperature; Acclimatization; Adaptation, Physiological; Global Warming; Adaptation, Psychological; Climate Change
PubMed: 37499408
DOI: 10.1016/j.jtherbio.2023.103588 -
Sports Medicine (Auckland, N.Z.) Jul 2023Heat adaptation regimes are used to prepare athletes for exercise in hot conditions to limit a decrement in exercise performance. However, the heat adaptation literature... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Heat adaptation regimes are used to prepare athletes for exercise in hot conditions to limit a decrement in exercise performance. However, the heat adaptation literature mostly focuses on males, and consequently, current heat adaptation guidelines may not be optimal for females when accounting for the biological and phenotypical differences between sexes.
OBJECTIVES
We aimed to examine: (1) the effects of heat adaptation on physiological adaptations in females; (2) the impact of heat adaptation on performance test outcomes in the heat; and (3) the impact of various moderators, including duration (minutes and/or days), total heat dose (°Cmin), exercise intensity (kcalmin), total energy expended (kcal), frequency of heat exposures and training status on the physiological adaptations in the heat.
METHODS
SPORTDiscus, MEDLINE Complete and Embase databases were searched to December 2022. Random-effects meta-analyses for resting and exercise core temperature, skin temperature, heart rate, sweat rate, plasma volume and performance tests in the heat were completed using Stata Statistical Software: Release 17. Sub-group meta-analyses were performed to explore the effect of duration, total heat dose, exercise intensity, total energy expended, frequency of heat exposure and training status on resting and exercise core temperature, skin temperature, heart rate and sweat rate. An explorative meta-regression was conducted to determine the effects of physiological adaptations on performance test outcomes in the heat following heat adaptation.
RESULTS
Thirty studies were included in the systematic review; 22 studies were meta-analysed. After heat adaptation, a reduction in resting core temperature (effect size [ES] = - 0.45; 95% confidence interval [CI] - 0.69, - 0.22; p < 0.001), exercise core temperature (ES = - 0.81; 95% CI - 1.01, - 0.60; p < 0.001), skin temperature (ES = - 0.64; 95% CI - 0.79, - 0.48; p < 0.001), heart rate (ES = - 0.60; 95% CI - 0.74, - 0.45; p < 0.001) and an increase in sweat rate (ES = 0.53; 95% CI 0.21, 0.85; p = 0.001) were identified in females. There was no change in plasma volume (ES = - 0.03; 95% CI - 0.31, 0.25; p = 0.835), whilst performance test outcomes were improved following heat adaptation (ES = 1.00; 95% CI 0.56, 1.45; p < 0.001). Across all moderators, physiological adaptations were more consistently observed following durations of 451-900 min and/or 8-14 days, exercise intensity ≥ 3.5 kcalmin, total energy expended ≥ 3038 kcal, consecutive (daily) frequency and total heat dose ≥ 23,000 °Cmin. The magnitude of change in performance test outcomes in the heat was associated with a reduction in heart rate following heat adaptation (standardised mean difference = - 10 beatsmin; 95% CI - 19, - 1; p = 0.031).
CONCLUSIONS
Heat adaptation regimes induce physiological adaptations beneficial to thermoregulation and performance test outcomes in the heat in females. Sport coaches and applied sport practitioners can utilise the framework developed in this review to design and implement heat adaptation strategies for females.
Topics: Male; Humans; Female; Hot Temperature; Thermotolerance; Adaptation, Physiological; Exercise; Body Temperature Regulation
PubMed: 37222863
DOI: 10.1007/s40279-023-01831-2 -
Sports Medicine (Auckland, N.Z.) Nov 2016Exercise training (ExT) prompts multiple beneficial adaptations associated with vascular health, such as increases in skeletal muscle capillarization and vascular... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Exercise training (ExT) prompts multiple beneficial adaptations associated with vascular health, such as increases in skeletal muscle capillarization and vascular dilator function and decreases in arterial stiffness. However, whether ExT performed in hypoxic conditions induces enhanced effects is unclear.
OBJECTIVE
We sought to systematically review the literature and determine whether hypoxic ExT leads to superior vascular adaptations compared with normoxic ExT.
METHODS
We searched MEDLINE, Scopus, and Web of Science from their inception until September 2015 for articles assessing vascular adaptations to ExT performed under hypoxic and normoxic conditions. We performed meta-analyses to determine the standardized mean difference (SMD) between the effects of ExT performed in hypoxia versus normoxia on vascular adaptations. We assessed heterogeneity among studies using I statistics and evaluated publication bias via the Begg and Mazumdar's rank correlation test and Egger's regression test.
RESULTS
After systematic review, we included 21 controlled studies, including a total of 331 individuals (mean age 19-57 years, 265 males). ExT programs primarily consisted of cycling endurance training performed in normobaric hypoxia or normoxia; duration ranged from 3 to 10 weeks. The exercise intensity was similar in relative terms in the groups trained in hypoxia and normoxia in the majority of studies (17 of 21). After data pooling, skeletal muscle capillarization (n = 182, SMD = 0.40, 95 % confidence interval [CI] 0.10-0.70; P = 0.01) and vascular dilator function (n = 71, SMD = 0.67, 95 % CI 0.17-1.18; P = 0.009) but not arterial stiffness (n = 112, SMD = -0.03, 95 % CI -0.69 to 0.63; P = 0.93), were enhanced with ExT performed in hypoxia versus normoxia. We only found heterogeneity among studies assessing arterial stiffness (I = 63 %, P = 0.02), and no publication bias was detected.
CONCLUSION
Based on current published studies, hypoxic ExT potentiates vascular adaptations related to skeletal muscle capillarization and dilator function. These findings may contribute to establishing effective exercise programs designed to enhance vascular health.
Topics: Acclimatization; Adult; Exercise; Humans; Hypoxia; Male; Middle Aged; Muscle, Skeletal; Oxygen Consumption; Vascular Stiffness; Young Adult
PubMed: 27286988
DOI: 10.1007/s40279-016-0570-5