Partial body cryotherapy exposure drives acute redistribution of circulating lymphocytes: preliminary findings.

Partial body cryotherapy (PBC) is proposed to alleviate symptoms of exercise-induced muscle damage (EIMD) by reducing associated inflammation. No studies have assessed acute PBC exposure on peripheral blood mononuclear cell mobilisation or compared these with cold water immersion (CWI), which may inform how PBC impacts inflammatory processes. This trial examined the impact of a single PBC exposure on circulating peripheral blood mononuclear cells compared to CWI or a control. 26 males were randomised into either PBC (3 min at - 110 to - 140 °C), CWI (3 min at 9 °C), or control (3 min at 24 °C), with blood samples, heart rate, and blood pressure taken before and after exposure. Cytometric analysis determined that CD8+ T-cell populations were significantly elevated after treatments, with PBC increasing CD8+ T cells to a greater degree than either CWI or CON. Natural killer cell counts were also elevated after PBC, with the increase attributed specifically to the CD56loCD16+ cytotoxic subset. This provides the first evidence for the effect of PBC exposure on redistribution of immune cells. An increase in circulating leukocyte subsets such as CD8+ T cells and CD56loCD16+ natural killer cells suggests that PBC may induce a transient mobilisation of lymphocytes. PBC may thus enable a more efficient trafficking of these cells from the circulation to the site of initial cellular insult from exercise, potentially accelerating the process of cellular recovery. This provides novel evidence on the use of PBC as a recovery treatment and may also have applicability in other clinical settings involving the recovery of damaged skeletal muscle.

The effect of aerobic exercise on tumour blood delivery: a systematic review and meta-analysis.

PURPOSE: Tumour blood vessels are structurally and functionally abnormal, resulting in areas of hypoxia and heterogeneous blood supply. Aerobic exercise may modulate tumour blood flow and normalise the tumour microenvironment to improve chemotherapy delivery. This systematic review and meta-analysis aimed to evaluate the effect of the aerobic exercise mode on tumour hypoxia, vascularisation and blood flow. METHODS: Four online databases were searched. Preclinical and clinical randomised controlled trials examining the effects of aerobic exercise training on hypoxia, vascularisation or blood flow in solid tumours were included. The risk of bias was assessed and a meta-analysis performed. RESULTS: Seventeen preclinical studies and one clinical study met criteria. Eleven studies assessed hypoxia, 15 studies assessed vascularisation and seven evaluated blood flow. There was large variability in measurement methods, tumour types and exercise program designs. The overall risk of bias was unclear in clinical and preclinical studies, owing to poor reporting. There was no significant effect of aerobic exercise on hypoxia (SMD = -0.17; 95% CI = -0.62, 0.28; I2 = 60%), vascularisation (SMD = 0.07; 95% CI = -0.40, 0.55; I2 = 71%) or blood flow (SMD = 0.01; 95% CI = -0.59, 0.61; I2 = 63%). CONCLUSION: There is heterogeneity in methodology, resulting in evidence that is inconsistent and inconclusive for the effects of aerobic exercise on hypoxia, vascularisation and blood flow. Most evidence of aerobic exercise effects on tumour blood flow is in animal models, with very limited evidence in humans.

Compression Socks Reduce Running-Induced Intestinal Damage.

ABSTRACT: Zadow, EK, Edwards, KH, Kitic, CM, Fell, JW, Adams, MJ, Singh, I, Kundur, A, Johnstone, ANB, Crilly, J, Bulmer, AC, Halson, SL, and, and Wu, SSX. Compression socks reduce running-induced intestinal damage. J Strength Cond Res 36(9): 2461-2464, 2022-Exercise is associated with a reduction in splanchnic blood flow that leads to the disruption of intestinal epithelium integrity, contributing to exercise-induced gastrointestinal syndrome. Strategies that promote intestinal blood flow during exercise may reduce intestinal damage, which may be advantageous for subsequent recovery and performance. This study aimed to explore if exercise-associated intestinal damage was influenced by wearing compression garments, which may improve central blood flow. Subjects were randomly allocated to wear compression socks ( n = 23) or no compression socks (control, n = 23) during a marathon race. Blood samples were collected 24 hours before and immediately after marathon and analyzed for intestinal fatty acid-binding protein (I-FABP) concentration as a marker of intestinal damage. The magnitude of increase in postmarathon plasma I-FABP concentration was significantly greater in control group (107%; 95% confidence interval [CI], 72-428%) when compared with runners wearing compression socks (38%; 95% CI, 20-120%; p = 0.046; d = 0.59). Wearing compression socks during a marathon run reduced exercise-associated intestinal damage. Compression socks may prove an effective strategy to minimize the intestinal damage component of exercise-induced gastrointestinal syndrome.

Microbial inputs at the litter layer translate climate into altered organic matter properties.

Plant litter chemistry is altered during decomposition but it remains unknown if these alterations, and thus the composition of residual litter, will change in response to climate. Selective microbial mineralization of litter components and the accumulation of microbial necromass can drive litter compositional change, but the extent to which these mechanisms respond to climate remains poorly understood. We addressed this knowledge gap by studying needle litter decomposition along a boreal forest climate transect. Specifically, we investigated how the composition and/or metabolism of the decomposer community varies with climate, and if that variation is associated with distinct modifications of litter chemistry during decomposition. We analyzed the composition of microbial phospholipid fatty acids (PLFAs) in the litter layer and measured natural abundance δ13 CPLFA values as an integrated measure of microbial metabolisms. Changes in litter chemistry and δ13 C values were measured in litterbag experiments conducted at each transect site. A warmer climate was associated with higher litter nitrogen concentrations as well as altered microbial community structure (lower fungi:bacteria ratios) and microbial metabolism (higher δ13 CPLFA ). Litter in warmer transect regions accumulated less aliphatic-C (lipids, waxes) and retained more O-alkyl-C (carbohydrates), consistent with enhanced 13 C-enrichment in residual litter, than in colder regions. These results suggest that chemical changes during litter decomposition will change with climate, driven primarily by indirect climate effects (e.g., greater nitrogen availability and decreased fungi:bacteria ratios) rather than direct temperature effects. A positive correlation between microbial biomass δ13 C values and 13 C-enrichment during decomposition suggests that change in litter chemistry is driven more by distinct microbial necromass inputs than differences in the selective removal of litter components. Our study highlights the role that microbial inputs during early litter decomposition can play in shaping surface litter contribution to soil organic matter as it responds to climate warming effects such as greater nitrogen availability.

Aerobic exercise during chemotherapy infusion for cancer treatment: a novel randomised crossover safety and feasibility trial.

PURPOSE: Exercise is a powerful adjunct therapy for patients diagnosed with cancer which can alleviate treatment side-effects and improve a range of outcomes including fatigue and health-related quality of life. Recently, preclinical evidence has suggested that if exercise is performed during chemotherapy infusion, there is enhanced perfusion that may improve drug delivery and attenuate the hypoxic microenvironment. This study aimed to determine the safety and feasibility of delivering an aerobic exercise intervention to cancer patients during chemotherapy infusion. METHODS: A randomised crossover trial was conducted for adults (18-60) undergoing chemotherapy treatment with non-vesicant agents for cancer. In randomised order, during two consecutive chemotherapy infusions, participants either received usual care or performed 20 min of supervised low-intensity cycling. RESULTS: Sixty-five percent of patients approached agreed to participate, and exercise was safely delivered with neither adverse events nor interference to treatment reported for all participants with a mixed cancer diagnosis (N = 10, 90% female, 51.2 ± 7.4 years). There were no significant differences between exercise and usual care in participant-reported difficulty or comfort levels, but exercise significantly reduced boredom (p = 0.01). No significant differences were detected in the symptoms experienced following either intervention. CONCLUSIONS: Exercise during chemotherapy infusion appears to be safe and feasible. Further research is required with a larger sample size to evaluate the impact on tumour perfusion, symptom experience, and opportunity for physical activity increase.

Carbohydrate intake and ketosis in self-sufficient multi-stage ultramarathon runners.

Ultra-endurance athletes accumulate an energy deficit throughout their events and those competing in self-sufficient multi-stage races are particularly vulnerable due to load carriage considerations. Whilst urinary ketones have previously been noted in ultra-endurance exercise and attributed to insufficient carbohydrate (CHO) availability, not all studies have reported concomitant CHO intake. Our aim was to determine changes in blood glucose and ß-hydroxybutyrate concentrations over five days (240 km) of a self-sufficient multi-stage ultramarathon in combination with quantification of energy and macronutrient intakes, estimated energy expenditure and evaluation of energy balance. Thirteen runners (8 male, 5 female, mean age 40 ± 8 years) participated in the study. Glucose and ß-hydroxybutyrate were measured every day immediately post-running, and food diaries completed daily. CHO intakes of 301 ± 106 g·day-1 (4.3 ± 1.8 g·kg-1·day-1) were not sufficient to avoid ketosis (5-day mean ß-hydroxybutyrate: 1.1 ± 0.6 mmol.L-1). Furthermore, ketosis was not attenuated even when CHO intake was high (9 g·kg-1·day-1). This suggests that competing in a state of ketosis may be inevitable during multi-stage events where load reduction is prioritised over energy provisions. Attenuating negative impacts associated with such a metabolic shift in athletes unaccustomed to CHO and energy restriction requires further exploration.

Temperature sensitivity of biomass-specific microbial exo-enzyme activities and CO2 efflux is resistant to change across short- and long-term timescales.

Accurate representation of temperature sensitivity (Q10 ) of soil microbial activity across time is critical for projecting soil CO2 efflux. As microorganisms mediate soil carbon (C) loss via exo-enzyme activity and respiration, we explore temperature sensitivities of microbial exo-enzyme activity and respiratory CO2 loss across time and assess mechanisms associated with these potential changes in microbial temperature responses. We collected soils along a latitudinal boreal forest transect with different temperature regimes (long-term timescale) and exposed these soils to laboratory temperature manipulations at 5, 15, and 25°C for 84 days (short-term timescale). We quantified temperature sensitivity of microbial activity per g soil and per g microbial biomass at days 9, 34, 55, and 84, and determined bacterial and fungal community structure before the incubation and at days 9 and 84. All biomass-specific rates exhibited temperature sensitivities resistant to change across short- and long-term timescales (mean Q10  = 2.77 ± 0.25, 2.63 ± 0.26, 1.78 ± 0.26, 2.27 ± 0.25, 3.28 ± 0.44, 2.89 ± 0.55 for ß-glucosidase, N-acetyl-ß-d-glucosaminidase, leucine amino peptidase, acid phosphatase, cellobiohydrolase, and CO2 efflux, respectively). In contrast, temperature sensitivity of soil mass-specific rates exhibited either resilience (the Q10 value changed and returned to the original value over time) or resistance to change. Regardless of the microbial flux responses, bacterial and fungal community structure was susceptible to change with temperature, significantly differing with short- and long-term exposure to different temperature regimes. Our results highlight that temperature responses of microbial resource allocation to exo-enzyme production and associated respiratory CO2 loss per unit biomass can remain invariant across time, and thus, that vulnerability of soil organic C stocks to rising temperatures may persist in the long term. Furthermore, resistant temperature sensitivities of biomass-specific rates in spite of different community structures imply decoupling of community constituents and the temperature responses of soil microbial activities.

Companion dog acquisition and mental well-being: a community-based three-arm controlled study.

BACKGROUND: Dog ownership is suggested to improve mental well-being, although empirical evidence among community dog owners is limited. This study examined changes in human mental well-being following dog acquisition, including four measures: loneliness, positive and negative affect, and psychological distress. METHODS: We conducted an eight-month controlled study involving three groups (n = 71): 17 acquired a dog within 1 month of baseline (dog acquisition); 29 delayed dog acquisition until study completion (lagged control); and 25 had no intentions of acquiring a dog (community control). All participants completed the UCLA Loneliness Scale (possible scores 0-60), Positive and Negative Affect Schedule and Kessler10 at baseline, three-months and eight-months. We used repeated measures ANCOVAs to analyse data with owner age and sex included as covariates. Post-hoc tests were performed for significant effects (p < 0.05). RESULTS: There was a statistically significant group by time interaction for loneliness (p = 0.03), with an estimated reduction of 8.41 units (95% CI -16.57, - 0.26) from baseline to three-months and 7.12 (95% CI -12.55, - 1.69) from baseline to eight-months in the dog acquisition group. The group by time interaction for positive affect was also significant (p = 0.03), although there was no change in the dog acquisition group. CONCLUSIONS: Companion dog acquisition may reduce loneliness among community dog owners. Our study provides useful direction for future larger trials on the effects of dog ownership on human mental well-being. TRIAL REGISTRATION: This trial was retrospectively registered on 5th July 2017 with the Australian New Zealand Clinical Trials Registry ( ACTRN12617000967381 ).

Heat stress and fetal risk. Environmental limits for exercise and passive heat stress during pregnancy: a systematic review with best evidence synthesis.

OBJECTIVE: Pregnant women are advised to avoid heat stress (eg, excessive exercise and/or heat exposure) due to the risk of teratogenicity associated with maternal hyperthermia; defined as a core temperature (Tcore) ≥39.0°C. However, guidelines are ambiguous in terms of critical combinations of climate and activity to avoid and may therefore unnecessarily discourage physical activity during pregnancy. Thus, the primary aim was to assess Tcore elevations with different characteristics defining exercise and passive heat stress (intensity, mode, ambient conditions, duration) during pregnancy relative to the critical maternal Tcore of ≥39.0°C. DESIGN: Systematic review with best evidence synthesis. DATA SOURCES: EMBASE, MEDLINE, SCOPUS, CINAHL and Web of Science were searched from inception to 12 July 2017. STUDY ELIGIBILITY CRITERIA: Studies reporting the Tcore response of pregnant women, at any period of gestation, to exercise or passive heat stress, were included. RESULTS: 12 studies satisfied our inclusion criteria (n=347). No woman exceeded a Tcore of 39.0°C. The highest Tcore was 38.9°C, reported during land-based exercise. The highest mean end-trial Tcore was 38.3°C (95% CI 37.7°C to 38.9°C) for land-based exercise, 37.5°C (95% CI 37.3°C to 37.7°C) for water immersion exercise, 36.9°C (95% CI 36.8°C to 37.0°C) for hot water bathing and 37.6°C (95% CI 37.5°C to 37.7°C) for sauna exposure. CONCLUSION: The highest individual core temperature reported was 38.9°C. Immediately after exercise (either land based or water immersion), the highest mean core temperature was 38.3°C; 0.7°C below the proposed teratogenic threshold. Pregnant women can safely engage in: (1) exercise for up to 35 min at 80%-90% of their maximum heart rate in 25°C and 45% relative humidity (RH); (2) water immersion (≤33.4°C) exercise for up to 45 min; and (3) sitting in hot baths (40°C) or hot/dry saunas (70°C; 15% RH) for up to 20 min, irrespective of pregnancy stage, without reaching a core temperature exceeding the teratogenic threshold.

The origin of soil organic matter controls its composition and bioreactivity across a mesic boreal forest latitudinal gradient.

Warmer climates have been associated with reduced bioreactivity of soil organic matter (SOM) typically attributed to increased diagenesis; the combined biological and physiochemical transformation of SOM. In addition, cross-site studies have indicated that ecosystem regime shifts, associated with long-term climate warming, can affect SOM properties through changes in vegetation and plant litter production thereby altering the composition of soil inputs. The relative importance of these two controls, diagenesis and inputs, on SOM properties as ecosystems experience climate warming, however, remains poorly understood. To address this issue we characterized the elemental, chemical (nuclear magnetic resonance spectroscopy and total hydrolysable amino acids analysis), and isotopic composition of plant litter and SOM across a well-constrained mesic boreal forest latitudinal transect in Atlantic Canada. Results across forest sites within each of three climate regions indicated that (1) climate history and diagenesis affect distinct parameters of SOM chemistry, (2) increases in SOM bioreactivity with latitude were associated with elevated proportions of carbohydrates relative to plant waxes and lignin, and (3) despite the common forest type across regions, differences in SOM chemistry by climate region were associated with chemically distinct litter inputs and not different degrees of diagenesis. The observed climate effects on vascular plant litter chemistry, however, explained only part of the regional differences in SOM chemistry, most notably the higher protein content of SOM from warmer regions. Greater proportions of lignin and aliphatic compounds and smaller proportions of carbohydrates in warmer sites' soils were explained by the higher proportion of vascular plant relative to moss litter in the warmer relative to cooler forests. These results indicate that climate change induced decreases in the proportion of moss inputs not only impacts SOM chemistry but also increases the resistance of SOM to decomposition, thus significantly altering SOM cycling in these boreal forest soils.

Who's the boss: determining the control pathways of cardiovascular and cellular immune responses to acute stress.

Acute stress responses are known to include increases in heart rate and blood pressure, as well as increases in the number of circulating immune cells, all of which are governed by the autonomic nervous system. This laboratory practical measures cardiovascular and circulating immune cell responses to a passive (cold pressor) and active (mental arithmetic) acute stress task in student participants. The results allow them to examine the different patterns of autonomic response they elicit (approximated by heart rate and blood pressure responses), and knowledge of these responses can then be used to infer the governing autonomic aspect of the increases in circulating immune cells from the results. This activity can be either adapted from teacher-led methods to inquiry, asking students to design the details of the acute stress tasks, or developed by asking students to design a follow-up experiment that could be used to provide direct evidence for their conclusions. Data collected provide a platform for teaching data analysis and interpretation, as well as critical thinking.

Driving in an urban environment, the stress response and effects of exercise.

Driving may be detrimental to health, with one hypothesis suggesting that driving may elicit an acute stress response and, with repeated exposures, may become a chronic stressor. The present study examined the stress response to driving and the effectiveness of a prior exercise bout in dampening this response. Twenty healthy adults performed three tasks: control, driving and exercise plus driving. Heart rate (HR), heart rate variability (HRV), blood pressure (BP) and cortisol were measured to quantify the acute stress response to each condition. Data indicated a stress response to driving: HR was elevated and HRV was reduced during the driving task compared with control. HR was elevated and HRV was reduced comparing the exercise plus driving with the driving condition. BP and cortisol were not different among conditions. The potential of interventions, such as exercise, to counter daily stressors should be evaluated to safeguard long-term health. Practitioner Summary: this study confirms that driving induces a stress response, with the exercise intervention providing mixed results (an increase in cardiovascular measures and a decrease in cortisol measure trending significance). Given the known consequences of stress and evidence that exercise can mitigate acute stress, further evaluation of exercise interventions is recommended.

Whole-body Cryotherapy as a Recovery Technique after Exercise: A Review of the Literature.

This review aims to evaluate the current body of literature investigating the effect of whole body cryotherapy on recovery after exercise. A systematic search was conducted to investigate the effect of whole body cryotherapy (WBC, exposure to temperatures between -110 to -190°C) on markers of recovery after damaging exercise in healthy, physically active subjects. Of the 16 eligible articles extracted, ten induced muscle damage using controlled exercise in a laboratory setting, while six induced damage during sport-specific training. Results indicated that muscle pain was reduced in 80% of studies following WBC. Two applied studies found recovery of athletic capacity and performance with WBC improved, variables of this nature were also improved in 71% of studies using controlled exercise. Further benefits of WBC treatment included reduction of systemic inflammation and lower concentrations of markers for muscle cell damage. These results suggest that WBC may improve recovery from muscle damage, with multiple exposures more consistently exhibiting improvements in recovery from pain, loss of muscle function, and markers of inflammation and damage. The diversity in muscle damage protocols, exposure timing with regards to exercise, as well as temperatures, duration and frequencies of exposure, make specific recommendations preliminary at present.

Progenitor cells are mobilized by acute psychological stress but not beta-adrenergic receptor agonist infusion.

OBJECTIVES: Stimuli that activate the sympathetic nervous system, such as acute psychological stress, rapidly invoke a robust mobilization of lymphocytes into the circulation. Experimental animal studies suggest that bone marrow-derived progenitor cells (PCs) also mobilize in response to sympathetic stimulation. Here we tested the effects of acute psychological stress and brief pharmacological ß-adrenergic (ßAR) stimulation on peripheral PC numbers in humans. METHODS: In two studies, we investigated PC mobilization in response to an acute speech task (n=26) and ßAR-agonist (isoproterenol) infusion (n=20). A subset of 8 participants also underwent the infusion protocol with concomitant administration of the ßAR-antagonist propranolol. Flow cytometry was used to enumerate lymphocyte subsets, total progenitor cells, total haematopoietic stem cells (HSC), early HSC (multi-lineage potential), late HSC (lineage committed), and endothelial PCs (EPCs). RESULTS: Both psychological stress and ßAR-agonist infusion caused the expected mobilization of total monocytes and lymphocytes and CD8(+) T lymphocytes. Psychological stress also induced a modest, but significant, increase in total PCs, HSCs, and EPC numbers in peripheral blood. However, infusion of a ßAR-agonist did not result in a significant change in circulating PCs. CONCLUSION: PCs are rapidly mobilized by psychological stress via mechanisms independent of ßAR-stimulation, although the findings do not exclude ßAR-stimulation as a possible cofactor. Considering the clinical and physiological relevance, further research into the mechanisms involved in stress-induced PC mobilization seems warranted.

Trait mindfulness is associated with blood pressure and interleukin-6: exploring interactions among subscales of the Five Facet Mindfulness Questionnaire to better understand relationships between mindfulness and health.

Mindfulness based interventions have been associated with improvements in physical health; however, the mechanisms underlying these changes are unclear. The current study explored relationships between trait mindfulness, blood pressure (BP) and interleukin-6 (IL-6). Relationships between physical health variables and (1) a composite score of mindfulness, (2) individual facets of mindfulness and (3) interactions between theoretically relevant pairs of mindfulness subscales were investigated. One hundred and thirty healthy, young adults [M (SD) age = 21.7(2.7) years] reported trait levels of mindfulness (Five Facet Mindfulness Questionnaire, subscales include: observing, describing, acting with awareness (AWA), nonjudging and nonreactivity), had their resting BP measured and underwent a blood draw to assesses circulating IL-6 levels. Age, gender, body mass index, race/ethnicity, depression and perceived stress were obtained and used as covariates. A composite score of trait mindfulness was associated with lower BP and a trend suggested that it was also associated with lower IL-6. Investigation of individual facets of mindfulness revealed interactions between the subscales AWA and nonjudging, such that higher endorsement of AWA was associated with lower BP only when nonjudging was also high. A second interaction was observed between the subscales observing and nonreactivity, such that higher endorsement of observing was associated with lower IL-6 only when levels of nonreactivity were also high. Trait mindfulness was associated with both BP and IL-6. Examining interactions between facets of mindfulness variables may be important in understanding how mindfulness based interventions influence physiology.

The effects of exercise on vaccination responses: a review of chronic and acute exercise interventions in humans.

Vaccination programs, although feted for success in reducing infectious disease morbidity and mortality, are limited by vaccine efficacy, which is particularly problematic in populations with reduced immune function. Exercise has been identified as a behavioural factor that can improve immune function in some settings and cohorts, and therefore, in the setting of vaccination, it may serve as an adjuvant for immune responses. Here, we summarise the body of evidence that has investigated the effects of chronic or acute exercise interventions on vaccination responses. A systematic search of the literature was conducted including six major databases. Randomised control trials (RCTs), cross-sectional and observational studies that involved a variety of population samples and that employed any modality or intensity of acute exercise or chronic training prior to vaccine administration and measured any immune response were included. Twenty trials met the inclusion criteria for this review. Nine studies investigated the effect of acute exercise on the immune response to vaccination, whilst the remaining eleven studies investigated the effect of chronic exercise. Most of the current published literature suggests that exposure to either acute or chronic exercise significantly augments the immune response to vaccination. The clinical importance of this adjuvant action of exercise, if any, as well as variability in responsiveness across different cohorts, dose-response relationships and the optimal exercise modality to employ for this indication deserve further study.

Is dog walking suitable for physical activity promotion? Investigating the exercise intensity of on-leash dog walking.

Background: Approximately a quarter of the global population is physically inactive, increasing the prevalence of chronic health conditions such as cardiovascular disease. Clearly, a population shift is needed to increase physical activity participation. Given almost half of American and Australian households have at least one dog, dog walking has the potential to increase physical activity. The objective of this study was to characterize the exercise intensity of dog walking using physiological measures to determine whether it achieved a threshold for health-enhancement. Method: From February 2020 to September 2022, dog owners (aged > 18 years, without impediment to walking) who resided in metropolitan Sydney participated in an on-leash dog walk for a minimum of 20 minutes, while wearing a heart rate monitor and carrying a phone to track cadence, route and duration. Results: Forty-three participants were recruited (aged 34.26 ± 16 years). Data from measures of %heart rate reserve (38 ± 10.8 %HRR), %heart rate max (61 ± 7.2 %HRmax) and average cadence (45 ± 8.4steps/min) classified dog-walking as light intensity. However, when using average walking speed (4.29 ± 0.8 km/hr) and metabolic equivalents (3.53 ± 0.6METs), the walk was classified as moderate intensity. Conclusion: Overall, depending on the intensity measure used, dog walking was positioned in the upper range of light intensity and the lower range of moderate intensity. Although dog walking at a certain intensity may be difficult to prescribe as strategy for meeting current moderate-to-vigorous focused physical activity recommendations, it should be recognised as a beneficial activity that may reach moderate intensity on some occasions.

Not All Yoga Styles Are the Same: An International Survey on Characteristics of Yoga Classes.

Objectives: Yoga is a multicomponent activity that has been associated with many health benefits. Different yoga styles contain different combinations and durations of components (e.g., postures, breathing, meditation, relaxation, and chanting). A better description and quantification of yoga components within different styles are important in understanding how different yoga styles contribute to health outcomes. This survey aims to understand the general characteristics and components taught in different yoga styles. Design: An online international survey was sent to yoga teachers (18+ years with >1 year teaching experience) using snowball recruitment. Survey questions included demographic and professional characteristics of participants, specialized yoga style, and details of components typically taught in the class. The analysis included descriptive statistics and a comparison between teachers of traditional versus exercise-based versus therapy styles using χ2 and Kruskal-Wallis tests. Results: Nine hundred and sixty-eight yoga teachers (76.8% female, mean age 43.8 ± 11.1 years) from 64 countries participated in the survey. When grouped according to primary yoga style taught, 70.6% of participants taught traditional (e.g., hatha or ashtanga), 18.4% exercise-based (e.g., vinyasa or power), and 11.0% therapy (e.g., restorative or gentle) styles. Nearly all teachers included physical postures, but breath techniques, chanting, and cleansing were included by significantly more traditional teachers (95.2%, 68.3%, 25.8%, respectively) compared with exercise-based (88.6%, 42.5%, 7.2%) and therapy teachers (93.0%, 43.0%, 10.0%). Variations were reported in the time allocated to each of these class components. Physical postures took up 50.0% of total class time for traditional styles, 60.9% for exercise-based, and 53.9% for therapy styles (p < 0.001). Conversely, breath techniques, meditation, relaxation, and chanting took significantly more of the class time for traditional and therapy compared with exercise-based styles. However, teachers from all styles regarded yoga poses, breathing, meditation, and relaxation as equally important in the yoga class. Conclusions: Exercise-based yoga styles unsurprisingly dedicate more time to physical postures and less time to nonphysical components than traditional and therapy yoga styles. However, all yoga teachers report valuing and including multiple components of yoga practice regardless of the primary style of teaching, which is reflective of the holistic nature of yoga practice. Further research into the benefits of the specific component combinations in different yoga styles is needed to better understand the full potential of yoga practice for health.

Effect of a single session of yoga and meditation on stress reactivity: A systematic review.

This systematic review synthesises the evidence for the effectiveness of a single session of yoga or its components including meditation and breathing techniques in reducing acute stress reactivity in healthy adults. Following the PRISMA guidelines, we searched Medline, EMBASE, Cochrane, CINAHL, and PsycINFO on 30th July 2023 for randomised controlled or crossover trials of yoga components and reporting physiological and/or psychological outcome measure(s) related to stress reactivity. Risk of bias (ROB) was assessed using the Cochrane ROB 2 tool. Data were synthesised narratively. Twenty-one out of 28 eligible studies (n = 2574) relating to 31 interventions (meditation [n = 22], breathing [n = 4] and yoga [n = 5]) reported outcomes in favour of the intervention. Stress reactivity was reported to be reduced by 71% of studies measuring physiological outcomes and 65% of studies measuring psychological outcomes. These studies show that a single session of yoga components is effective in reducing acute stress reactivity in adults and could be recommended for stress management. Future studies with larger populations and a more equal representation of genders and age groups are warranted.