Hannah J. Moir

Interleukin-6 in combination with the interleukin-6 receptor stimulates glucose uptake in resting human skeletal muscle independently of insulin action

To examine if the physiological concentrations of both interleukin‐6 (IL‐6), in combination with IL‐6 receptor (IL‐6R), are able to stimulate glucose uptake in human skeletal muscle and to identify the associated signalling pathways.

The contributions of oxidative stress, oxidised lipoproteins and AMPK towards exercise-associated PPARγ signalling within human monocytic cells

Abstract Peroxisome proliferator-activated receptor gamma (PPARγ) is known to be activated via exercise-associated transient increases in oxidative stress. However, the precise mechanism(s) triggering PPARγ activation in monocytes during/following exercise remain to be confirmed. Here, two cohorts of five healthy male individuals undertook exercise bouts (cycling; 70% O2max; 45 min) in the presence/absence of dietary antioxidant supplementation (vitamins C (1000 mg/day) and E (400IU/day) for four weeks before exercise); monocytic 5’ adenosine monophosphate-activated protein kinase (AMPK)/PPARγ co-activator-1alpha (PGC-1α)/PPARγ signalling was investigated in samples obtained before exercise and up to 24 h after exercise, while THP-1 cells were cultured as an in vitro monocyte model. In THP-1 cells, AMPKα1 was phosphorylated within 1h of menadione (15 μM)-triggered increases in [reactive oxygen species (ROS)]cyto, an effect which was followed by upregulation of PPARγ and several of its target genes (PGC-1α, liver X receptor alpha [LXRα] and ATP-binding cassette subfamily A, member 1 [ABCA1]; 24–72 h), with these effects being blunted by co-administration of vitamin C (62.5 μM). Conversely, treatment with oxidised low-density lipoprotein (oxLDL) (1 μg/mL; 24–72 h), but not non-oxidised LDL, upregulated the above PPARγ-regulated genes without affecting AMPKα1 phosphorylation. In vivo, dietary antioxidant supplementation (which is known to prevent exercise-triggered increases in oxLDL levels) blunted exercise-associated upregulation of the above PPARγ-regulated genes, but had no effect on exercise-associated transient [ROS]cyto increases, or on AMPK phosphorylation. These data suggest that exercise-associated PPARγ signalling effects appear, at least in monocytes, to be mediated by increased generation of PPARγ ligands via oxidation of lipoproteins (following exercise-associated transient increases in oxidative stress), rather than via [ROS]cyto-mediated AMPK activation. These findings may be of clinical relevance, as PPARγ activation in monocytes is associated with beneficial effects related to type-2 diabetes and its cardiovascular complications.

Physiological and perceptual responses to Latin partnered social dance

The purpose of this study was to investigate the physiological and perceptual responses to Latin partnered social dance to salsa music when performed as a self-selected activity within an ecologically valid setting. Eighteen non-professional adult Latin dancers undertook a laboratory-based graded exercise test for determination of maximal oxygen uptake and maximal heart rate. The dancers then attended two Latin partnered social dance sessions in established salsa venues in London, UK over a 2 wk period. Physiological data were collected using a wrist-worn ActiGraph wGT3X+ accelerometer with accompanying heart rate monitor. Perceived benefits of dance were assessed via the Exercise Benefits/Barriers Scale, and measurement of state intrinsic motivation during dance was undertaken using the Intrinsic Motivation Inventory. Total step count during 2h of dance was not different (t16 = -.39, p = .71) between females and males (9643 ± 1735 step); however, women expended a significantly lower (t16 = -2.57, p < .05) total energy expenditure when compared to men (479 ± 125 versus 651 ± 159 kcal). Dancers of both genders considered interest-enjoyment to be the motivator of primary importance. The highest rated perceived benefit of dance was psychological outlook. Latin partnered social dance to salsa music demands moderate to vigorous physical activity intensity levels, and further, fosters interest, enjoyment, and a positive psychological outlook among novice to advanced adult Latin dancers taking part primarily for leisure purposes. These findings may be of use for those interested in the efficacy of Latin social dancing as an expressive medium for the promotion of community health.

Salsa dance and Zumba fitness: Acute responses during community-based classes

Background Research interest in both partnered Latin dance and non-partnered Latin-themed aerobic dance has increased in recent years, likely a result of the gaining popularity of these types of instructor-led group classes among the mainstream dance and fitness audiences; however, the efficacy of these activities for the purposes of health promotion currently remains unclear. The purpose of this study was to simultaneously assess the physiological responses and psychological experiences during salsa dance and Zumba fitness in a community sample of physically inactive women. Methods Twenty-four participants, aged 22–56 years, visited the laboratory to perform a graded exercise test for determination of maximal oxygen uptake and maximal heart rate. The participants then attended 2 partnered salsa dance and 2 non-partnered Zumba fitness classes each in a counterbalanced order over a 2-week period. The 1-h classes were taught by certified instructors in established venues in the Royal Borough of Kingston and the surrounding communities of London, UK. Physiological data were collected using a wrist-worn ActiGraph wGT3X+ accelerometer with accompanying heart rate monitor and were processed using previously validated dance-specific techniques. Psychological experiences were measured via the Subjective Exercise Experiences Scale. Results There was a significantly higher (p < 0.001) total time spent in moderate-to-vigorous physical activity (51.2 ± 3.1 vs. 32.6 ± 5.9 min), total energy expenditure (411 ± 66 vs. 210 ± 46 kcal), and total step count (6773 ± 556 vs. 4108 ± 781 steps) during Zumba fitness when compared to salsa dance. Significant pre- to post-class improvements in positive well-being (p < 0.01, partial η2 = 0.41) and psychological distress (p < 0.001, partial η2 = 0.72) were simultaneously observed for both salsa dance and Zumba fitness. Conclusion The acute responses to classes of partnered Latin dance and non-partnered Latin-themed aerobic dance suggest that in physically inactive women participation is indeed efficacious in terms of community-based physical activity and psychosocial health promotion.

The health-enhancing efficacy of Zumba® fitness: An 8-week randomised controlled study

ABSTRACT The purpose of this study was to gain a holistic understanding of the efficacy of Zumba® fitness in a community-recruited cohort of overweight and physically inactive women by evaluating (i) its physiological effects on cardiovascular risk factors and inflammatory biomarkers and (ii) its mental health-enhancing effects on factors of health-related quality of life (HRQoL). Participants were randomly assigned to either engagement in one to two 1 h classes of Zumba® fitness weekly (intervention group; n = 10) or maintenance of habitual activity (control group; n = 10). Laboratory assessments were conducted pre- (week 0) and post-intervention (week 8) with anthropometric, physiological, inflammatory and HRQoL data collected. In the intervention group, maximal oxygen uptake significantly increased (P < 0.05; partial η2 = 0.56) by 3.1 mL · kg−1 · min−1, per cent body fat significantly decreased (P < 0.05; partial η2 = 0.42) by –1.2%, and interleukin-6 and white blood cell (WBC) count both significantly decreased (P < 0.01) by –0.4 pg · mL−1 (partial η2 = 0.96) and –2.1 × 109 cells · L−1 (partial η2 = 0.87), respectively. Large magnitude enhancements were observed in the HRQoL factors of physical functioning, general health, energy/fatigue and emotional well-being. When interpreted in a community-based physical activity and psychosocial health promotion context, our data suggest that Zumba® fitness is indeed an efficacious health-enhancing activity for adults.

Untargeted metabolomics profiling of an 80.5 km simulated treadmill ultramarathon

Metabolomic profiling of nine trained ultramarathon runners completing an 80.5 km self-paced treadmill-based time trial was carried out. Plasma samples were obtained from venous whole blood, collected at rest and on completion of the distance (post-80.5 km). The samples were analyzed by using high-resolution mass spectrometry in combination with both hydrophilic interaction (HILIC) and reversed phase (RP) chromatography. The extracted putatively identified features were modeled using Simca P 14.1 software (Umetrics, Umea, Sweden). A large number of amino acids decreased post-80.5 km and fatty acid metabolism was affected with an increase in the formation of medium-chain unsaturated and partially oxidized fatty acids and conjugates of fatty acids with carnitines. A possible explanation for the complex pattern of medium-chain and oxidized fatty acids formed is that the prolonged exercise provoked the proliferation of peroxisomes. The peroxisomes may provide a readily utilizable form of energy through formation of acetyl carnitine and other acyl carnitines for export to mitochondria in the muscles; and secondly may serve to regulate the levels of oxidized metabolites of long-chain fatty acids. This is the first study to provide evidence of the metabolic profile in response to prolonged ultramarathon running using an untargeted approach. The findings provide an insight to the effects of ultramarathon running on the metabolic specificities and alterations that may demonstrate cardio-protective effects.

Rationale and Design of an Online Educational Program Using Game-Based Learning to Improve Nutrition and Physical Activity Outcomes Among University Students in the United Kingdom

Abstract Objective: To assess the impact of an online game-based educational program on nutrition knowledge and dietary and physical activity habits among university students in the United Kingdom. Design: Randomized controlled trial with pre- and postintervention comparisons. Setting: Two higher education settings in London, UK. Subjects: Current undergraduate and postgraduate students of two universities (n = 88) aged 18–34 years are randomly allocated to an intervention (n = 44) or a control group (n = 44). Intervention: The intervention group will receive access to an educational website and online quizzes with gamification elements, including information about healthy eating and physical activity. The control group will receive no information. Duration of the intervention will be 10 weeks. Measures of Outcome: Primary outcome is nutrition knowledge. Secondary outcomes include dietary and activity habits. Nutrition knowledge and dietary and activity habits will be assessed using questionnaires. Weekly steps will be counted using pedometers. Assessment of anthropometric and metabolic risk factors will take place. Analysis: Quantitative analysis will investigate changes in nutrition knowledge between the two groups of the study population. Linear regression analysis will be used, if the data follow the normal distribution (otherwise binomial regression analysis), to examine whether field of study, residence status, body mass index (BMI), and demographic factors affect nutrition knowledge. Associations between changes in knowledge and dietary and physical activity behavior will be assessed by correlations. Conclusions/Implications: The study will provide insights with regard to the design and use of online game-playing as a cost-effective approach to improve nutritional knowledge among university students.

Classification of Physical Activity Cut-Points and the Estimation of Energy Expenditure During Walking Using the GT3X+ Accelerometer in Overweight and Obese Adults

ABSTRACT This study establishes tri-axial activity count (AC) cut-points for the GT3X+ accelerometer to classify physical activity intensity in overweight and obese adults. Further, we examined the accuracy of established and novel energy expenditure (EE) prediction equations based on AC and other metrics. Part 1: Twenty overweight or obese adults completed a 30 minute incremental treadmill walking protocol. Heart rate (HR), EE, and AC were measured using the GT3X+ accelerometer. Part 2: Ten overweight and obese adults conducted a self-paced external walk during which EE, AC, and HR were measured. Established equations (Freedson et al., 1998; Sasaki et al., 2011) overestimated EE by 40% and 31%, respectively (p < .01). Novel gender-specific prediction equations provided good estimates of EE during treadmill and outdoor walking (standard error of the estimate = .91 and .65, respectively). We propose new cut-points and prediction equations to estimate EE using the GT3X+ tri-axial accelerometer in overweight and obese adults.

Static stretching does not enhance recovery in elite youth soccer players

Background Static stretching (SS) is a recovery intervention used for the reduction of muscle soreness postexercise. The effects of SS on elite young footballers have received little attention, and therefore the aim of this study was to assess the effects of SS on muscle recovery following competitive soccer matches in elite young footballers. Methods Ten male participants (16±1 years) were recruited from an English Premier League professional soccer academy. Using a controlled crossover design, participants followed one of two recovery interventions (SS or passive recovery (PR)) immediately following completion of competitive soccer matches. Muscle oedema, creatine kinase (CK), countermovement jump with arms (CMJA) performance and perceived muscle soreness were assessed before, immediately after and 48 hours postmatch. Results Competitive soccer matches significantly induced muscle damage, with time intervals of perceived soreness and CK showing significant increases (p<0.05), and CMJA showing significant decreases between prematch, postmatch and 48 hours postmatch for both SS and PR (p<0.05). Comparisons of the absolute effects of SS with PR only revealed significant decreases for CK 48 hours postmatch (p<0.05) as a result of SS intervention. Conclusion The current study demonstrated competitive soccer matches induced muscle damage, which may have detrimental effects on future performance within 24–48 hours postmatch. Furthermore, there was limited evidence to suggest SS would assist in the reduction of muscle soreness postexercise. Therefore, it can be argued that SS is not a beneficial recovery option for elite youth soccer players.

Physiological and psychological responses to Latin partner-based social dancing under free-living conditions

Previous literature has shown a small but positive effect of exercise on cognitive function in young people (Chang et al [2012]. Brain Research, 1453, 87-101), though this relationship is complicated by factors such as the mode, intensity and duration of exercise, the components of cognitive function examined and the timing of the cognitive tests relative to exercise. Specifically, bilateral coordinative exercise (exercise with a greater cognitive involvement) has been demonstrated to improve subsequent attention in adolescents (Budde et al [2008]. Neuroscience Letters, 441, 229-223). The aim of the present study was to examine the effects of a circuit of aerobic and coordinative exercises on Stroop test performance in adolescents. Following approval from the institutions ethical advisory committee, 34 adolescents (age: 13.2±0.3 years; height: 155.4±6.0 cm; body mass: 50.2±9.9 kg) completed a familiarisation session followed by two (exercise and resting) experimental trials. Sixty minutes following provision of an ad libitum breakfast (matched for subsequent experimental trial), participants completed the 15 min bout of exercise or continued to rest. The exercise consisted of a circuit of 10 exercises (alternate aerobic and coordinative exercises), each completed for 1 min with 30 s rest between stations. The Stroop test, measuring attention and executive function, was completed 30 min pre-, 5 min post- and 60 min post-exercise. Heart rate during the exercise was 158±15 beats.min-1. Response times were not different across the morning on the exercise and resting trials, between the baseline and complex levels of the Stroop test (trial by session time by test level interaction, P=0.408). However, there was a significant trial by session time by test level interaction for accuracy on the Stroop test (P=0.039).Upon further analysis, this was due to an improvement in accuracy 5 min post-exercise on the baseline level of the Stroop test (exercise + 2.1%, resting -1.8 %; trial by session time interaction, P=0.010), an effect which was not evident on the complex level (trial by session time interaction, P=0.543). The findings of the present study suggest that the accuracy of attention and executive function (as assessed by the Stroop test) is enhanced immediately following circuits based exercise in adolescents, but that this effect is not evident 60 min post-exercise. There was no effect of the circuits based exercise on response times on the Stroop test. These results have implications for school policy makers, given the importance of cognitive function (and in particular executive function) for academic performance.