The importance of ergonomics across several scientific domains, including biomechanics, psychology, sociology, and physiology, have been extensively explored. However, the role of other factors that ...may influence the health and productivity of workers, such as nutrition, is generally overlooked. Nutra-ergonomics describes the interface between workers, their work environment, and performance in relation to their nutritional status. It considers nutrition to be an integral part of a safe and productive workplace that encompasses physical and mental health as well as the long-term wellbeing of workers. This review explores the knowledge, awareness, and common practices of nutrition, hydration, stimulants, and fortified product use employed prior to physical employment standards testing and within the workplace. The influence of these nutra-ergonomic strategies on physical employment standards, worker safety, and performance will be examined. Further, the roles, responsibilities, and implications for the applicant, worker, and the employer will be discussed within the context of nutra-ergonomics, with reference to the provision and sustainability of an environment conducive to optimize worker health and wellbeing. Beyond physical employment standards, workplace productivity, and performance, the influence of extended or chronic desynchronization (irregular or shift work) in the work schedule on metabolism and long-term health, including risk of developing chronic and complex diseases, is discussed. Finally, practical nutra-ergonomic strategies and recommendations for the applicant, worker, and employer alike will be provided to enhance the short- and long-term safety, performance, health, and wellbeing of workers.
Celotno besedilo
Dostopno za:
DOBA, FSPLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Oral contraceptive (OC) use influences peak exercise responses to training, however, the influence of OC on central and peripheral adaptations to exercise training are unknown. This study ...investigated the influence of OC use on changes in time-to-fatigue, pulmonary oxygen uptake, cardiac output, and heart rate on-kinetics, as well as tissue saturation index to 4 weeks of sprint interval training in recreationally active women.
Women taking an oral contraceptive (OC;
= 25) or experiencing natural menstrual cycles (MC;
= 22) completed an incremental exercise test to volitional exhaustion followed by a square-wave step-transition protocol to moderate (90% of power output at ventilatory threshold) and high intensity (Δ50% of power output at ventilatory threshold) exercise on two separate occasions. Time-to-fatigue, pulmonary oxygen uptake on-kinetics, cardiac output, and heart rate on-kinetics, and tissue saturation index responses were assessed prior to, and following 12 sessions of sprint interval training (10 min × 1 min efforts at 100-120% PPO in a 1:2 work:rest ratio) completed over 4 weeks.
Time-to-fatigue increased in both groups following training (
< 0.001), with no difference between groups. All cardiovascular on-kinetic parameters improved to the same extent following training in both groups. Greater improvements in pulmonary oxygen up-take kinetics were seen at both intensities in the MC group (
< 0.05 from pre-training) but were blunted in the OC group (
> 0.05 from pre-training). In contrast, changes in tissue saturation index were greater in the OC group at both intensities (
< 0.05); with the MC group showing no changes at either intensity.
Oral contraceptive use may reduce central adaptations to sprint interval training in women without influencing improvements in exercise performance - potentially due to greater peripheral adaptation. This may be due to the influence of exogenous oestradiol and progestogen on cardiovascular function and skeletal muscle blood flow. Further investigation into female-specific influences on training adaptation and exercise performance is warranted.
PURPOSEOral contraceptive (OC) use reduces peak aerobic capacity (V˙O2peak); however, whether it also influences adaptations to training has yet to be determined. This study aimed to examine the ...influence of OC use on peak performance (peak power output PPO) and physiological adaptations (V˙O2peak and peak cardiac output Q˙peak) after sprint interval training (SIT) in recreationally active women.
METHODSWomen taking an OC (n = 25) or experiencing natural regular menstrual cycles (MC; n = 16) completed an incremental exercise test to assess V˙O2peak, PPO, and Q˙peak before, immediately after, and 4 wk after 12 sessions of SIT. The SIT consisted ten 1-min efforts at 100% to 120% PPO in a 1:2 work–rest ratio.
RESULTSThough V˙O2peak increased in both groups after SIT (both P < 0.001), the MC group showed greater improvement (OC, +8.5%; MC, +13.0%; P = 0.010). Similarly, Q˙peak increased in both groups, with greater improvement in the MC group (OC, +4.0%; MC, +16.1%; P = 0.013). PPO increased in both groups (OC, +13.1%; MC, +13.8%; NS). All parameters decreased 4 wk after SIT cessation, but remained elevated from pretraining levels; the OC group showed more sustained training effects in V˙O2peak (OC, −4.0%; MC, −7.7%; P = 0.010).
CONCLUSIONSIT improved peak exercise responses in recreationally active women. However, OC use dampened V˙O2peak and Q˙peak adaptation. A follow-up period indicated that OC users had spared V˙O2peak adaptations, suggesting that OC use may influence the time course of physiological training adaptations. Therefore, OC use should be verified, controlled for, and considered when interpreting physiological adaptations to exercise training in women.
People with multiple myeloma (MM) often experience disease symptoms and treatment toxicities that can be alleviated through physical activity (PA). However, the majority of people with MM are ...insufficiently active. This study explored PA among people with MM, including differences by treatment stage, symptoms and demographics, and programming preferences. Overall, 126 people with MM (77% response rate) completed the survey. Pre-diagnosis, 25.4% were sufficiently active, with 12.0% remaining active after treatment. Respondents who were physically active pre-diagnosis were 46.7 times (95% confidence intervals CI: 2.03, 1072.1) more likely to meet PA guidelines following an MM diagnosis compared to people not meeting guidelines pre-diagnosis. Experiencing MM symptoms and receiving PA advice from healthcare professionals were not associated with meeting PA guidelines. People with MM were interested in exercise programs (55%) that are low-cost (77%), offered at flexible times (74%), and at locations close to home (69%), both during active treatment and remission (57%), and supervised by an exercise oncology specialist (48%). People with MM, particularly those insufficiently active prior to diagnosis, should be offered convenient, low-cost exercise programs supervised by an exercise oncology specialist to increase PA participation.
BACKGROUND.Patients with advanced liver disease are at increased risk of infection and other complications. A significant proportion of patients also have poor fitness and low muscle mass. The ...primary aim of this study was to investigate if cardiorespiratory fitness and body composition are risk factors for sepsis and other complications of advanced liver disease.
METHODS.Patients being listed for liver transplantation underwent cardiopulmonary exercise testing to determine ventilatory threshold (VT). Computed tomography was used to measure skeletal muscle and subcutaneous and visceral adipose tissue indexes. All unplanned hospital admissions, deaths or delistings before transplantation were recorded.
RESULTS.Eighty-two patients (aged 55.1 50.6–59.4 years, median (interquartile range); male 87% achieved a median VT of 11.7 (9.7–13.4) mL·kg·min. Their median model of end-stage liver disease, incorporating serum sodium score was 18 (14–22); and 37 had hepatocellular carcinoma. There were 50 admissions in 31 patients; with 16 admissions for sepsis in 13 patients. Patients with sepsis had a significantly lower VT (sepsis, 9.5 7.8–11.9; no sepsis, 11.8 10.5–13.8 mL·kg·min; P = 0.003. No body composition variables correlated with sepsis, nor were there any significant associations between VT and unplanned admissions for other indications. Multivariate logistic regression demonstrated that VT was independently associated with a diagnosis of sepsis (P = 0.03). Poisson regression revealed that VT was a significant predictor for the number of septic episodes (P = 0.02); independent of age, model of end-stage liver disease, incorporating serum sodium score, hepatocellular carcinoma diagnosis, presence of ascites, and β-blocker use.
CONCLUSIONS.Poor cardiorespiratory fitness is an independent risk factor for the development of sepsis in advanced liver disease.
This study investigated the acceptable accuracy of common body composition techniques compared with the reference 4-compartment (4C-R) model, which has not been investigated in a sample with diverse ...characteristics, including age and sex. Techniques included components of the 4C-R model dual-energy X-ray absorptiometry, air displacement plethysmography, deuterium dilution (DD) and surrogate compartment models, which utilised bioelectrical impedance spectroscopy (BIS) rather than DD. Men and women (sex = 1:1, 18–85 years, n = 90) completed body composition testing under best-practice guidance. For measurement of individuals, only the reference 3-compartment (3C-R) equation met acceptable error limits (<5% error among individuals) within the a priori cut-point (80%) for fat-free mass (FFM; CV = 0.52%) and fat mass (FM; CV = 1.61%). However, all investigated techniques reached equivalency to the 4C-R model for FFM on average (CV = 0.52–4.31%), but for FM only the 3C and 4C equations that included quantification of total body water (TBW) by DD or BIS reached equivalency overall (CV = 1.61–6.68%). Sex and age minimally influenced accuracy. Only the 3C-R or 4C-R equations are supported for acceptable individual accuracy for both FFM and FM. For group estimates any investigated technique could be used with acceptable accuracy for FFM; however, for FM, inclusion of TBW measurement within a compartment model is necessary.
Novelty:
Only the referent 3C and 4C models (including deuterium dilution) provide accurate body composition results that are acceptable for measurement of individuals in the general population.
For group estimates of lean mass in the general population, compartments models that include TBW must be used for accurate measurement.
Celotno besedilo
Dostopno za:
DOBA, FSPLJ, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Body composition can substantially impact elite swimming performance. In practice, changes in fat and lean mass of elite swimmers are estimated using body mass, sum of seven skinfolds (∑7) and lean ...mass index (LMI). However, LMI may be insufficiently accurate to detect small changes in body composition which could meaningfully impact swimming performance. This study developed equations which estimate dual-energy x-ray absorptiometry (DXA)-derived lean and fat mass using body mass and ∑7 data. Elite Australian swimmers (n = 44; 18 male, 26 female) completed a DXA scan and standardised body mass and ∑7 measurements. Equations to estimate DXA-derived lean and fat mass based on body mass, ∑7 and sex were developed. The relationships between ∑7, body mass and DXA-derived lean and fat mass were non-linear. Fat mass (Adjusted R
2
= 0.91; standard error = 1.0 kg) and lean mass (Adjusted R
2
= 0.99; standard error = 1.0 kg) equations were considered sufficiently accurate. Lean mass estimates outperformed the LMI in identifying the correct direction of change in lean mass (82% correct; LMI 71%). Using the accurate estimations produced by these equations will enhance the prescription and evaluation of programmes to optimise the body composition and subsequent performance in swimmers.
Physical exercise may reduce dementia risk in aging, but varying reports on its effectiveness make it challenging to ascribe what level of exercise will have significant longer-term effects on ...important functions such as hippocampal-based learning and memory. This study compared the effect of three different 6-month exercise regimens on hippocampal-dependent cognition in healthy, elderly individuals. Participants, aged 65-85 with no cognitive deficits, were randomly assigned to one of three exercise interventions (low (LIT), medium (MIT), and High intensity interval training (HIIT), respectively). Each participant attended 72 supervised exercise sessions over a 6-month period. A total of 151 participants completed all sessions. Cognitive testing for hippocampal performance occurred monthly, as did blood collection, and continued for up to 5 years following initiation of the study. Multimodal 7 Tesla MRI scans were taken at commencement, 6 and 12 months. After 6 months, only the HIIT group displayed significant improvement in hippocampal function, as measured by paired associative learning (PAL). MRI from the HIIT group showed abrogation of the age-dependent volumetric decrease within several cortical regions including the hippocampus and improved functional connectivity between multiple neural networks not seen in the other groups. HIIT-mediated changes in the circulating levels of brain-derived neurotrophic factor (BDNF) and cortisol correlated to improved hippocampal-dependent cognitive ability. These findings demonstrate that HIIT significantly improves and prolongs the hippocampal-dependent cognitive health of aged individuals. Importantly, improvement was retained for at least 5 years following initiation of HIIT, suggesting that the changes seen in hippocampal volume and connectivity underpin this long-term maintenance. Sustained improvement in hippocampal function to this extent confirms that such exercise-based interventions can provide significant protection against hippocampal cognitive decline in the aged population. The changes in specific blood factor levels also may provide useful biomarkers for choosing the optimal exercise regimen to promote cognitive improvement.Physical exercise may reduce dementia risk in aging, but varying reports on its effectiveness make it challenging to ascribe what level of exercise will have significant longer-term effects on important functions such as hippocampal-based learning and memory. This study compared the effect of three different 6-month exercise regimens on hippocampal-dependent cognition in healthy, elderly individuals. Participants, aged 65-85 with no cognitive deficits, were randomly assigned to one of three exercise interventions (low (LIT), medium (MIT), and High intensity interval training (HIIT), respectively). Each participant attended 72 supervised exercise sessions over a 6-month period. A total of 151 participants completed all sessions. Cognitive testing for hippocampal performance occurred monthly, as did blood collection, and continued for up to 5 years following initiation of the study. Multimodal 7 Tesla MRI scans were taken at commencement, 6 and 12 months. After 6 months, only the HIIT group displayed significant improvement in hippocampal function, as measured by paired associative learning (PAL). MRI from the HIIT group showed abrogation of the age-dependent volumetric decrease within several cortical regions including the hippocampus and improved functional connectivity between multiple neural networks not seen in the other groups. HIIT-mediated changes in the circulating levels of brain-derived neurotrophic factor (BDNF) and cortisol correlated to improved hippocampal-dependent cognitive ability. These findings demonstrate that HIIT significantly improves and prolongs the hippocampal-dependent cognitive health of aged individuals. Importantly, improvement was retained for at least 5 years following initiation of HIIT, suggesting that the changes seen in hippocampal volume and connectivity underpin this long-term maintenance. Sustained improvement in hippocampal function to this extent confirms that such exercise-based interventions can provide significant protection against hippocampal cognitive decline in the aged population. The changes in specific blood factor levels also may provide useful biomarkers for choosing the optimal exercise regimen to promote cognitive improvement.
Cancer treatments exert vascular toxic effects that can lead to the development of cardiovascular disease. Exercise training has the potential to prevent or reduce cancer treatment-induced damage to ...vascular structure and function. This systematic review with meta-analyses aimed to determine the isolated effects of exercise training on vascular outcomes in people with cancer.
Seven electronic databases were searched on 20 September 2021 to identify randomised controlled trials, quasi-randomised trials, pilot and cohort studies. Included studies implemented a structured exercise intervention and assessed vascular structure and/or function in people during or following cancer treatment. Meta-analyses examined the effects of exercise training on endothelial function (via brachial artery flow-mediated dilation) and arterial stiffness (via pulse wave velocity). Methodological quality was assessed using the Cochrane Quality Assessment tool and modified Newcastle-Ottawa Quality Appraisal tool. Grading of Recommendations, Assessment, Development and Evaluations framework was used to assess the certainty of evidence.
Ten studies (discussed across 11 articles) met the inclusion criteria. Methodological quality of the included studies was moderate (71% average). Exercise improved vascular function when compared to control (standardised mean difference = 0.34, 95% CI (0.01, 0.67); p = 0.044: studies = 5, participants = 171), but not pulse wave velocity (standardised mean difference = - 0.64, 95% CI (- 1.29, 0.02); p = 0.056: studies = 4, participants = 333). The certainty of evidence was moderate for flow-mediated dilation and low for pulse wave velocity.
Compared to usual care, exercise training significantly improves flow-mediated dilation (endothelial function) but not pulse wave analysis, in people treated for cancer.
Exercise may improve vascular health in individuals during and following cancer treatment.
Regular exercise has been recommended as a potential strategy to counteract the age-related bone loss experienced by men; however, the optimal exercise prescription is not known.
To perform a pilot ...study to examine the osteogenic effect, safety and feasibility of a combined program of upper body resistance exercise and two doses of impact-loading exercise on bone mineral density (BMD) of middle-aged and older men.
Forty-two community-dwelling men aged 50-74 years were randomly assigned to either an exercise program of combined upper body resistance exercise and either high-dose impact-loading (HI; 80 jumps per session) or moderate-dose impact-loading (MOD; 40 jumps per session) or a control (CON) group. The 9-month intervention involved 4 sessions each week: 2 supervised clinic-based and 2 home-based. BMD of the lumbar spine, femoral neck, total hip, trochanter and whole body as well as lean and fat mass were assessed at baseline and 9 months by dual-energy X-ray absorptiometry. Bone turnover markers, hormone levels, physical function and muscle strength were also assessed.
Following 9 months of training, significant differences in BMD among groups were found at the total hip (p = 0.010) and trochanter (p = 0.047) with BMD in the MOD group decreasing relative to the HI group. Although not significant, the HI group consistently preserved BMD, whereas BMD of the MOD and CON groups declined at the hip sites. Mean change for all groups at all skeletal sites was approximately within ±1%. There was no change in bone turnover markers. There were no adverse events as a result of the intervention; however, overall attendance for the HI and MOD groups was 53% (clinic: 68%, home: 38%) and 65% (clinic: 74%, home: 55%), respectively.
This study indicates that while impact-loading exercise can be safely undertaken in middle-aged and older men, the current combined program did not elicit significant improvements in BMD.
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