The efficacy of high-intensity interval training (HIIT) to elicit physiological and performance adaptations in endurance athletes has been established in men and to a lesser extent in women. This ...study compared lactate threshold (LT
2
) and performance adaptations to HIIT between men and women. Nine male and eight female cyclists and triathletes completed trials to determine their LT
2
and 40 km cycling performance before, and after 10 HIIT sessions. Each HIIT session consisted of 10 × 90 s at peak power output, separated by 60 s active recovery. Main effects showed that HIIT improved peak power output (p = 0.05; ES: 0.2); relative peak power output (W.kg
−1
; p = 0.04; ES: 0.3 and W.kg
−0.32
; p = 0.04; ES: 0.3); incremental time to fatigue (p = 0.01; ES: 0.4), time trial time (p < 0.001; ES: 0.7) and time trial power output (p < 0.001; ES: 0.7) equally in both sexes. Although LT
2
power output explained 77% of the performance improvement in women, no variable explained the performance improvement in men, suggesting another mechanism(s) was involved. Although HIIT improved cycling performance in men and women, it might not be appropriate to evaluate the effectiveness of HIIT using the same variables for both sexes.
Physical activity (PA) is an independent predictor of mortality and frailty in middle-aged women, but fatigue remains a major barrier in this group. While caffeine intake has been associated with ...reduced exertion and perceived fatigue, it is not well understood whether consumption of naturally caffeinated drinks is associated with physical activity. The aim of this study was to determine whether habitual consumption of coffee and tea is associated with participation in physical activity. Women (
= 7580) from the Australian Longitudinal Study on Women's Health were included in this investigation. Participants reported average tea and coffee intake over the last 12 months and usual PA. Logistic regression models were adjusted for relevant health and lifestyle confounders, and Sobel test was used for mediation analysis. Participants who consumed 1⁻2 cups of coffee/day were 17% more likely to meet the recommended 500 metabolic equivalent (MET).min/week than women who had <1 cup/day (odds ratio (OR) 1.17, 95% confidence interval (CI) 1.04⁻1.32). Participants who reported drinking either 1⁻2 cups or >3 cups/day of tea were 13⁻26% more likely to meet 500 MET.min/week than those who had <1 cup/day (OR 1.26, 95% CI 1.08⁻1.46 and OR 1.13, 95% CI 1.01⁻1.26, respectively). Tiredness and energy mediated associations between intake of coffee (fully) and tea (partially) and PA. Middle-aged women who drink 1⁻2 cups of coffee or >1 cup of tea/day are more likely to meet the moderate-to-vigorous PA guidelines than those who drink <1 cup/day. Future research is warranted to investigate causality and effects of specific coffee and tea amounts.
Purpose
To explore the attitudes and practices of clinical haematologists towards promoting physical activity (PA) and exercise for patients with multiple myeloma (MM).
Methods
Using a quantitative ...cross-sectional survey, clinical haematologists reported on the perceived benefits and acceptability of PA and exercise and frequency, confidence and barriers to providing exercise advice.
Results
Clinical haematologists (n=34; 68% response rate), who cumulatively treated ~340 patients with MM each week, completed the survey. Almost all (97%) agreed that PA was important, with benefits for quality of life, activities of daily living, mental health and fatigue. Whilst 88% discussed PA at least occasionally with their patients, approximately two-thirds were not confident advising specific exercises (68%) or identifying PA resources (62%). Despite this, 44% never referred patients to exercise professionals, with 18% only doing so if the patient asked. Over half did not recommend exercise when patients had spine fractures or were physically unwell. No differences were observed in individual factors (age, gender, practice type and own PA participation) and promotion of PA.
Conclusions
Clinical haematologists perceive PA as important, but lack confidence on what exercise/s to recommend and if exercise is appropriate for specific disease complications. They tend to not refer patients to exercise professionals.
Implications for Cancer Survivors
Patients with MM often suffer from symptoms and toxicities that may be alleviated through PA. However, PA participation rates are low. Support for clinical haematologists for when and how to discuss exercise, and clearer referral pathways to exercise professionals may improve PA uptake and hence ensure access to optimal care, thereby improving patient outcomes.
Fluid replacement during cycling exercise evolves on a spectrum from simply drinking to thirst to planned structured intake, with both being appropriate recommendations. However, with mixed findings ...suggesting fluid intake may or may not improve endurance cycling performance (ECP) in a diverse range of trained individuals, there is a clear need for summarised evidence regarding the effect of fluid consumption on ECP.
(1) Determine the magnitude of the effect of drinking fluid on performance during cycling exercise tasks of various durations, compared with no drinking; (2) examine the relationship between rates of fluid intake and ECP; and (3) establish fluid intake recommendations based on the observations between rates of fluid intake and ECP.
Meta-analysis.
Studies were located via database searches and cross-referencing. Performance outcomes were converted to a similar metric to represent percentage change in power output. Fixed- and random-effects weighted mean effect summaries and meta-regression analyses were used to identify the impact of drinking fluid on ECP.
A limited number of research manuscripts (n = 9) met the inclusion criteria, producing 15 effect estimates. Meta-regression analyses demonstrated that the impact of drinking on ECP under 20-33 °C ambient temperatures was duration-dependent. Fluid consumption of, on average, 0.29 mL/kg body mass/min impaired 1 h high-intensity (80% peak oxygen uptake Formula: see texto
) ECP by -2.5 ± 0.8% (95% confidence interval CI -4.1 to -0.9%) compared with no fluid ingestion. In contrast, during >1 to ≤2 h and >2 h moderate-intensity (60-70% Formula: see texto
) cycling exercise, ECP improved by 2.1 ± 1.5% (95% CI 1.2-2.9%) and 3.2 ± 1.2% (95% CI 0.8-5.6%), respectively, with fluid ingestion compared with no fluid intake. The associated performance benefits were observed when the rates of fluid intake were in the range of 0.15-0.20 mL/kg body mass/min for >1 to ≤2 h cycling exercise and ad libitum or 0.14-0.27 mL/kg body mass/min for cycling exercise >2 h.
A rate of fluid consumption of between 0.15 and 0.34 mL/kg body mass/min during high-intensity 1 h cycling exercise is associated with reductions in ECP. When cycling at moderate intensity for >1 to ≤2 h, cyclists should expect a gain in performance of at least 2% if fluid is consumed at a rate of 0.15-0.20 mL/kg body mass/min. For cycling exercise >2 h conducted at moderate intensity, consuming fluid ad libitum or at a rate of 0.14-0.27 mL/kg body mass/min should improve performance by at least 3%. Until further research is conducted, these recommendations should be used as a guide to inform hydration practices.
Exercise and physical activity have been shown to reduce the risk of many common cancers and strongly influence tumor biology. A cause-effect mechanism explaining this relationship is dependent on ...cellular pathways that can influence tumor growth and are exercise responsive. The insulin-like growth factor (IGF) axis is reported to promote the development and progression of carcinomas through cellular signaling in cancerous tissues. This review summarizes the physiologic basis of the role of the IGF axis in oncology and the influence of exercise on this process. We examined the effects of exercise prescription on the IGF axis in cancer survivors by evaluating the current scope of the literature. The current research demonstrates a remarkable heterogeneity and inconsistency in the responses of the IGF axis to exercise in breast, prostate, and colorectal cancer survivors. Finally, this review presents an in-depth exploration of the physiologic basis and mechanistic underpinnings of the seemingly disparate relationship between exercise and the IGF axis in oncology. Although there is currently insufficient evidence to categorize the effects of exercise prescription on the IGF axis in cancer survivors, the inconsistency of results suggests a multifaceted relationship, the complexities of which are considered in this review.
Reliability of body composition measurement techniques is essential to the accurate reporting of intervention outcomes. However, the between-day precision error of commonly used techniques, as well ...as the reference multi-compartment model, in a population-representative sample are currently unknown.
To quantify technical and biological precision error of body composition techniques in comparison to the referent 4-compartment (4C) model.
Men and women (1:1 ratio; 18–85 years old; n = 90) completed 2 consecutive-day body composition testing sessions, including individual components of the referent 4C model. Testing was undertaken in accordance with best practice guidance for each technique, including standardized presentation and a consistent time of day. Repeat measurements were conducted on day 1 for technical precision, and between-day measurements were conducted for biological precision quantification.
On average, all measurements met acceptable error limits and presented typically low technical and biological error <2% fat-free mass (FFM) and < 3% fat mass (FM) precision error. For technical precision of FFM, all techniques met a priori cut points (80%; CV = 0.45–0.81%). For FM, all techniques were equivalent to the best-rating method on average (CV = 0.78–1.35%), except air displacement plethysmography (CV = 2.13%). For biological precision, only 3-compartment (3C) and 4C equations sufficiently met the a priori determined cut point for estimates for FFM (CV = 0.77–0.79%), and only DXA met the 80% cut point (CV = 1.17%) for FM.
The primary purpose of a study design is imperative when deciding on body composition assessment techniques used for longitudinal measurements. If reliable longitudinal assessments of FFM are central, a 3C or 4C model may be indicated. If FM is a primary outcome, DXA may be preferable. However, considering the low error rates presented within the current study across a broad age span of healthy adults with implementation of best-practice guidelines, any technique assessed here may be used, provided that strict protocols are adhered to.
▪
Perturbation of the insulin/insulin-like growth factor (IGF) signaling system is often cited as a mechanism driving breast cancer risk. A systematic review identified prospective cohort studies and ...Mendelian randomization studies that examined the effects of insulin/IGF signaling (IGF, their binding proteins (IGFBP), and markers of insulin resistance on breast cancer risk. Meta-analyses generated effect estimates; risk of bias was assessed and the Grading of Recommendations Assessment, Development and Evaluation system applied to evaluate the overall quality of the evidence. Four Mendelian randomization and 19 prospective cohort studies met our inclusion criteria. Meta-analysis of cohort studies confirmed that higher IGF-1 increased risk of breast cancer; this finding was supported by the Mendelian randomization studies. IGFBP-3 did not affect breast cancer. Meta analyses for connecting-peptide and fasting insulin showed small risk increases, but confidence intervals were wide and crossed the null. The quality of evidence obtained ranged from 'very low' to 'moderate'. There were insufficient studies to examine other markers of insulin/IGF signaling. These findings do not strongly support the biological plausibility of the second part of the physical activity-insulin/IGF signaling system-breast cancer pathway. Robust conclusions cannot be drawn due to the dearth of high quality studies. See related article by Swain et al., p. 2106.
Aviation Rescue Firefighters (ARFF) require physical fitness specific to the aviation environment. This study aims to determine the physical fitness of ARFF and predictors of performance on ...ARFF-specific tasks from laboratory-based fitness measures.
Cross-sectional, observational study.
Forty-two male ARFF (mean±SD; age 38.4±7.6 years, body mass index 26.2±2.2kgm−2) completed a physical fitness testing battery, comprising maximal aerobic capacity (V˙O2max), lactate threshold, anaerobic power, body composition (dual-energy X-ray absorptiometry), muscular strength (3 repetition maximum (3RM) bench and leg press) and muscular endurance (maximum curl ups and push ups) under controlled laboratory conditions. On a separate occasion, ARFF completed timed work-related tasks including a hose drag, dummy drag, Stihl saw hold, stair climb and simulated ARFF emergency protocol.
All participants finished the simulated ARFF emergency protocol under the criterion time (5min 50s); the average completion time was 4min and 31s. Performance time on the simulated ARFF emergency protocol was inversely correlated to V˙O2max (r=−0.514; p<0.001), anaerobic step test performance (r=−0.549; p<0.001), height (r=−0.325; p=0.038) and lean mass (r=−0.429; p=0.005). Higher fat mass (r=0.318; p=0.043) and % body fat (r=0.481; p=0.001) were associated with slower performance time. Muscular strength, muscular endurance and flexibility were not related to performance on the simulated ARFF emergency protocol.
Aerobic and anaerobic capacities, as well as body composition are the strongest predictors of simulated ARFF emergency protocol performance. This study highlights the importance of aerobic and anaerobic fitness, compared to muscular strength or muscular endurance, for ARFF job-specific performance, employment and training.
Purpose
Exercise interventions can increase physical activity and wellbeing of people living with/beyond cancer. However, little is known about maintenance of physical activity in this population ≥ ...6 months post-exercise intervention, when theoretical evidence suggests behaviour maintenance occurs. Study aims are to (i) systematically review maintenance of physical activity ≥ 6-month post-exercise intervention, and (ii) investigate the influence of behaviour change techniques (BCTs) on physical activity maintenance in people living with/beyond cancer.
Methods
CINAHL, CENTRAL, EMBASE and PubMed databases were searched for randomised controlled trials up to August 2021. Trials including adults diagnosed with cancer that assessed physical activity ≥ 6 months post-exercise intervention were included.
Results
Of 142 articles assessed, 21 reporting on 18 trials involving 3538 participants were eligible. Five (21%) reported significantly higher physical activity ≥ 6 months post-exercise intervention versus a control/comparison group. Total number of BCTs (M = 8, range 2–13) did not influence intervention effectiveness. The BCTs Social support, Goal setting (behaviour), and Action planning, alongside supervised exercise, were important, but not sufficient, components for long-term physical activity maintenance.
Conclusions
Evidence for long-term physical activity maintenance post-exercise intervention for people living with/beyond cancer is limited and inconclusive. Further research is required to ensure the physical activity and health benefits of exercise interventions do not quickly become obsolete.
Implications for Cancer Survivors
Implementation of the BCTs Social support, Goal setting (behaviour), and Action planning, alongside supervised exercise, may enhance physical activity maintenance and subsequent health outcomes in people living with/beyond cancer.
Physical activity may reduce the risk of developing breast cancer via its effect on the insulin/insulin-like growth factor (IGF) signaling system. A systematic review searched for randomized ...controlled trials (RCT), Mendelian randomization and prospective cohort studies that examined the effects of physical activity on insulin/IGF signaling IGFs, their binding proteins (IGFBP), and markers of insulin resistance in adult women. Meta-analyses were performed to generate effect estimates. Risk of bias was assessed, and the Grading of Recommendations Assessment, Development, and Evaluation system used to determine the overall quality of the evidence. Fifty-eight RCTs met our inclusion criteria, no observational or Mendelian randomization studies met the criteria for inclusion. Meta-analyses indicated that physical activity interventions (vs. control) reduced fasting insulin, the Homeostatic Model Assessment for Insulin Resistance and fasting glucose. Physical activity increased IGF-1, but there was no clear effect on IGFBP-3 or the ratio of IGF-1:IGFBP-3. Strong evidence was only established for fasting insulin and insulin resistance. Further research is needed to examine the effect of physical activity on C-peptide and HBA1c in women. Reductions in fasting insulin and insulin resistance following exercise suggest some biological plausibility of the first part of the physical activity-insulin/IGF signaling-breast cancer pathway. See related article by Drummond et al., p. 2116.
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