An investigative study into the influence of a commercially available carbohydrate-protein-electrolyte beverage on short term repeated exercise performance

Background: The purpose of this study was to undertake an independent investigation into the effects of ingesting a carbohydrate-protein-electrolyte (CPE) beverage on repeated submaximal and time-trial cycling performance. Methods: Sixteen recreationally trained males (height: 1.76 +/- 0.07 m; weight: 70.05 +/- 7.90 kg; VO2max: 49.69 +/- 4.19 ml.kg1.min1) performed two exercise trials separated by 7 days. Each trial comprised two bouts of 90 minutes exercise separated by a 2 hour recovery period. Each bout comprised 45 minutes exercise on a cycle-ergometer at 60%VO2max (ST), followed immediately by a 45 minute performance test (PT). Participants were randomly assigned an 8% CPE beverage or colour/taste matched placebo (PL) prior to each trial. Participants consumed 100 ml of the assigned beverage every 10 minutes during each ST, and 500 ml at 0 and 60 minutes into recovery (total caloric delivery per trial: 617.6 kcal for CPE and12.8 kcal for PL). Mean power output (W), speed (km.hr1) and distance covered (km) were assessed throughout both trials. Expired air was sampled at 10 minute intervals throughout ST. Blood glucose and lactate were assessed during ST and recovery. RESULTS: Distance covered during ST was significantly reduced with PL by 9.12% (20.18 +/- 0.28 km in ST1 v 18.34 +/- 0.36 km in ST2; P = 0.0001). With CPE, distance covered, power output and average speed were maintained between ST1 and ST2. Oxygen uptake was not significantly different between ST1 and ST2, or conditions. Respiratory exchange ratio (RER) values decreased from 0.98 +/- 0.02 in ST1 to 0.91 +/- 0.02 in ST2 for PL (P = 0.003), supporting reduced total carbohydrate oxidation rates (P = 0.007). Mean blood glucose was maintained in CPE across ST trials, and was significantly greater than PL in ST2 (4.77 +/- 0.09 mmol.L1 for CPE compared with 4.18 +/- 0.06 mmol.L1 for PL, P <0.001). Mean distance during PT2 was 2.96 km (or 17.1%) further with CPE than PL (P = 0.003). Mean power significantly decreased across PT with PL (134.21 +/- 4.79 W and 106.90 +/- 3.25 W, respectively; P <0.04). Conclusions: The use of a CPE beverage improves short-term repeated exercise and subsequent performance compared to PL. Higher rates of carbohydrate oxidation, maintenance of plasma glucose, and decreased levels of fatigue may be beneficial for secondary bouts of performance and faster recovery turnover.Peer reviewe

Extending Whitney's extension theorem: nonlinear function spaces

We consider a global, nonlinear version of the Whitney extension problem for manifold-valued smooth functions on closed domains $C$, with non-smooth boundary, in possibly non-compact manifolds. Assuming $C$ is a submanifold with corners, or is compact and locally convex with rough boundary, we prove that the restriction map from everywhere-defined functions is a submersion of locally convex manifolds and so admits local linear splittings on charts. This is achieved by considering the corresponding restriction map for locally convex spaces of compactly-supported sections of vector bundles, allowing the even more general case where $C$ only has mild restrictions on inward and outward cusps, and proving the existence of an extension operator.Comment: 37 pages, 1 colour figure. v2 small edits, correction to Definition A.3, which makes no impact on proofs or results. Version submitted for publication. v3 small changes in response to referee comments, title extended. v4 crucial gap filled, results not affected. v5 final version to appear in Annales de l'Institut Fourie

Regulation of Arabidopsis 14-3-3 gene expression by GABA.

The function in plants of the non-protein amino acid, gamma-aminobutyric acid (GABA) is poorly understood. In this study, we show that GABA down-regulates the expression of a large sub-set of 14-3-3 gene family members in Arabidopsis thaliana seedlings in a calcium, ethylene and abscisic acid-dependent manner. Gene expression is not affected when seedlings are supplied with glutamate, a precursor of GABA. The repression of 14-3-3 gene expression by GABA is dependent on functional ethylene and abscisic acid signalling pathways, since the response is lost in the etr1-1, abi1-1 and abi2-1 mutants. Calcium measurements show that in contrast to glutamate, GABA does not elicit a cytoplasmic calcium elevation, suggesting that the GABA response is unlikely to be mediated by glutamate receptors, as has been suggested previously. We suggest that in addition to its role as a stress-related metabolite, GABA may regulate gene expression in Arabidopsis, including members of the 14-3-3 gene family

The weak choice principle WISC may fail in the category of sets

The set-theoretic axiom WISC states that for every set there is a set of surjections to it cofinal in all such surjections. By constructing an unbounded topos over the category of sets and using an extension of the internal logic of a topos due to Shulman, we show that WISC is independent of the rest of the axioms of the set theory given by a well-pointed topos. This also gives an example of a topos that is not a predicative topos as defined by van den Berg.Comment: v2 Change of title and abstract; v3 Almost completely rewritten after referee pointed out critical mistake. v4 Final version. Will be published in Studia Logica. License is CC-B

International labour mobility and unemployment

We develop a two-country labour-market model characterised by union wage-bargaining, in which the unemployed incur individual-specific costs of seeking work abroad. We explore the effects on equilibrium unemployment in each country of changes in union bargaining strength, the ratio of unemployment benefits to wages, and employers' willingness to hire foreign workers. Unfavourable labour-market institutions increase unemployment abroad as well as at home. We find that no country has an incentive to internationalise its own labour market unilaterally, because all the employment gains spill over abroad, which gives countries a strong incentive to co-ordinate on internationalisation.international labour mobility, unions, wage bargaining, globalization, unemployment

The effects of Montmorency tart cherry juice supplementation and FATMAX exercise on fat oxidation rates and cardio-metabolic markers in healthy humans

Montmorency tart cherries (Prunus cerasus L.) are rich in anthocyanins, compounds capable of augmenting fat oxidation and regulating metabolic dysfunction. The present study examined whether Montmorency tart cherry juice (MTCJ) supplementation could augment fat oxidation rates at rest and during FATMAX exercise, thus improve cardio-metabolic health. Eleven, healthy participants consumed MTCJ or placebo (PLA) twice daily, in a randomised, counterbalanced order for 20 days. Participants cycled at FATMAX for 1-h pre-, mid- (10 days) and post-supplementation whilst substrate oxidation rates were measured. Before exercise anthropometrics and resting metabolic rate were measured. Blood pressure, serum triglycerides, cholesterol, HDL, total antioxidant status (TAS) and glucose were measured immediately before and after exercise. No significant differences between conditions or interactions were observed for any functional and blood-based cardio-metabolic markers or fat oxidation during exercise or rest (P > 0.05). Pre-exercise TAS (P = 0.036) and HDL (P = 0.001) were significantly reduced from mid- to post-supplementation with MTCJ only. Twenty days’ MTCJ supplementation had no effect on fat oxidation; therefore, it is unnecessary for individuals in this participant cohort to consume MTCJ with exercise to improve cardio-metabolic biomarkers.Peer reviewedFinal Accepted Versio

On (2,3)-agreeable Box Societies

The notion of $(k,m)$-agreeable society was introduced by Deborah Berg et al.: a family of convex subsets of $\R^d$ is called $(k,m)$-agreeable if any subfamily of size $m$ contains at least one non-empty $k$-fold intersection. In that paper, the $(k,m)$-agreeability of a convex family was shown to imply the existence of a subfamily of size $\beta n$ with non-empty intersection, where $n$ is the size of the original family and $\beta\in[0,1]$ is an explicit constant depending only on $k,m$ and $d$. The quantity $\beta(k,m,d)$ is called the minimal \emph{agreement proportion} for a $(k,m)$-agreeable family in $\R^d$. If we only assume that the sets are convex, simple examples show that $\beta=0$ for $(k,m)$-agreeable families in $\R^d$ where $k<d$. In this paper, we introduce new techniques to find positive lower bounds when restricting our attention to families of $d$-boxes, i.e. cuboids with sides parallel to the coordinates hyperplanes. We derive explicit formulas for the first non-trivial case: the case of $(2,3)$-agreeable families of $d$-boxes with $d\geq 2$.Comment: 15 pages, 10 figure