Dark chocolate supplementation reduces the oxygen cost of moderate intensity cycling

BACKGROUND: Dark chocolate (DC) is abundant in flavanols which have been reported to increase the bioavailability and bioactivity of nitric oxide (NO). Increasing NO bioavailability has often demonstrated reduced oxygen cost and performance enhancement during submaximal exercise. METHODS: Nine moderately-trained male participants volunteered to undertake baseline (BL) measurements that comprised a cycle [Formula: see text] test followed by cycling at 80 % of their established gas exchange threshold (GET) for 20-min and then immediately followed by a two-minute time-trial (TT). Using a randomised crossover design participants performed two further trials, two weeks apart, with either 40 g of DC or white chocolate (WC) being consumed daily. Oxygen consumption, RER, heart rate and blood lactate (BLa) were measured during each trial. RESULTS: DC consumption increased GET and TT performance compared to both BL and WC (P < 0.05). DC consumption increased [Formula: see text] by 6 % compared to BL (P < 0.05), but did not reach statistical significance compared to WC. There were no differences in the moderate-intensity cycling for [Formula: see text], RER, BLa and heart rate between conditions, although, [Formula: see text] and RER exhibited consistently lower trends following DC consumption compared to BL and WC, these did not reach statistical significance. CONCLUSION: Chronic supplementation with DC resulted in a higher GET and enhanced TT performance. Consequently, ingestion of DC reduced the oxygen cost of moderate intensity exercise and may be an effective ergogenic aid for short-duration moderate intensity exercise

Twenty-one days of spirulina supplementation lowers heart rate during submaximal cycling and augments power output during repeated sprints in trained cyclists

Spirulina supplementation is reported to improve time to exhaustion and V̇O2max. However, there is limited information on its influence over the multiple intensities cyclists experience during training and competition. Fifteen trained males (Age 40 ± 8 years, V̇O2max 51.14 ± 6.43 ml/min/kg) ingested 6g/day of spirulina or placebo for twenty-one days in a double-blinded randomized cross over design, with a fourteen-day washout period between trials. Participants completed a 1-hour submaximal endurance test at 55% external power output max and a 16.1km time trial (day 1), followed by a lactate threshold test and repeated sprint performance tests (RSPTs) (day 2). Heart rate (bpm), Respiratory Exchange Ratio, oxygen consumption (ml/min/kg), lactate and glucose (mmol/L), time (secs), power output (Watts), and hemoglobin (g/L) were compared across conditions. Following spirulina supplementation, lactate and heart rate were significantly lower (P0.05). Spirulina supplementation reduces homeostatic disturbances during submaximal exercise and augments power output during RSPTs.Novelty bullets:• Spirulina supplementation lowers heart rate and blood lactate during ≈1-hour submaximal cycling. • Spirulina supplementation elicits significant augmentations in hemoglobin and power outputs during RSPTs

An electromyographic analysis of combining weights and elastic tubes as a method of resistance for exercise

The study aimed to compare the effects of elastic and weight resistance exercise on muscular activation patterns. Twenty‐one moderately active males (age = 25 ± 8) performed ten bicep curls and leg extensions with weights (W), an equivalent elastic resistance (T), and a combined condition (TW) of half elastic tension and half weight resistance. Muscular activations of the biceps, triceps, rectus femoris, vastus medialis, and lateralis were recorded with Trigno wireless electrodes, and joint angles were recorded with Qualisys Track Manager. Biceps total activation was highest (P < .001) with weights during the bicep curl due to an increased (P ≤ .007) activation in the eccentric phase. The biceps was also active over a larger portion of the ROM under TW (110°‐70° elbow angle), while W and T exhibited peak activations at mid (90°)‐ and late (50°) stages of ROM, respectively. The triceps (bicep curl) was least active (P < .05) with W throughout the concentric phase, as were the vastus medialis and lateralis (leg extension). Although peak and total activation were similar for most muscles in all conditions, muscular activation patterns differed between conditions indicating that TW may enhance strength gains by increasing time under tension, engaging agonist muscles at less advantageous lengths, and increasing the recruitment of auxiliary muscles

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

Functionality of the Crosswise Model for Assessing Sensitive or Transgressive Behavior: A Systematic Review and Meta-Analysis

Tools for reliable assessment of socially sensitive or transgressive behavior warrant constant development. Among them, the Crosswise Model (CM) has gained considerable attention. We systematically reviewed and meta-analyzed empirical applications of CM and addressed a gap for quality assessment of indirect estimation models. Guided by the PRISMA protocol, we identified 45 empirical studies from electronic database and reference searches. Thirty of these were comparative validation studies (CVS) comparing CM and direct question (DQ) estimates. Six prevalence studies exclusively used CM. One was a qualitative study. Behavior investigated were substance use and misuse (k = 13), academic misconduct (k = 8), and corruption, tax evasion, and theft (k = 7) among others. Majority of studies (k = 39) applied the “more is better” hypothesis. Thirty-five studies relied on birthday distribution and 22 of these used P = 0.25 for the non-sensitive item. Overall, 11 studies were assessed as high-, 31 as moderate-, and two as low quality (excluding the qualitative study). The effect of non-compliance was assessed in eight studies. From mixed CVS results, the meta-analysis indicates that CM outperforms DQ on the “more is better” validation criterion, and increasingly so with higher behavior sensitivity. However, little difference was observed between DQ and CM estimates for items with DQ prevalence estimate around 50%. Based on empirical evidence available to date, our study provides support for the superiority of CM to DQ in assessing sensitive/transgressive behavior. Despite some limitations, CM is a valuable and promising tool for population level investigation.publishedVersio

Plasma free fatty acids metabolic profile with LC-MS and appetite-related hormones in South Asian and White European men in relation to adiposity, physical activity and cardiorespiratory fitness : a cross-sectional study

South Asians have a greater cardiovascular disease (CVD) and type 2 diabetes (T2D) risk than white Europeans, but the mechanisms are poorly understood. This study examined ethnic differences in free fatty acids (FFAs) metabolic profile (assessed using liquid chromatography-mass spectrometry), appetite-related hormones and traditional CVD and T2D risk markers in blood samples collected from 16 South Asian and 16 white European men and explored associations with body composition, objectively-measured physical activity and cardiorespiratory fitness. South Asians exhibited higher concentrations of five FFAs (laurate, myristate, palmitate, linolenic, linoleate; p ≤ 0.040), lower acylated ghrelin (ES = 1.00, p = 0.008) and higher leptin (ES = 1.11, p = 0.004) than white Europeans; total peptide YY was similar between groups (p = 0.381). South Asians exhibited elevated fasting insulin, C-reactive protein, interleukin-6, triacylglycerol and ratio of total cholesterol to high-density lipoprotein cholesterol (HDL-C) and lower fasting HDL-C (all ES ≥ 0.74, p ≤ 0.053). Controlling for body fat percentage (assessed using air displacement plethysmography) attenuated these differences. Despite similar habitual moderate-to-vigorous physical activity (ES = 0.18, p = 0.675), V ˙ O2max was lower in South Asians (ES = 1.36, p = 0.001). Circulating FFAs in South Asians were positively correlated with body fat percentage (r2 = 0.92), body mass (r2 = 0.86) and AUC glucose (r2 = 0.89) whereas in white Europeans FFAs were negatively correlated with total step counts (r2 = 0.96). In conclusion, South Asians exhibited a different FFA profile, lower ghrelin, higher leptin, impaired CVD and T2D risk markers and lower cardiorespiratory fitness than white Europeans

Spirulina supplementation improves oxygen uptake in arm cycling exercise

Abstract: Purpose: Spirulina has previously been reported to improve high-intensity exercise performance and hemoglobin. However, spirulina’s effect on arm cycling exercise has yet to be investigated. The purpose of this study was to investigate the responses of spirulina supplementation on hemoglobin and on oxygen uptake, RER and HR during seated arm cycling exercise. Methods: In a double-blinded randomized crossover design, eleven males untrained in arm cycling ingested 6 g/day of spirulina or placebo for seven days. Seated on the Arm Crank Ergometer, each participant performed a baseline V̇O2max test, and then after supplementation, 2 × 30-min submaximal exercise bouts corresponding to 55% of their V̇O2max, followed by an incremental test to fatigue. A seven-day wash-out period was required between conditions. Oxygen uptake, RER and HR were measured continuously during exercise and hemoglobin measured prior to exercise after both conditions. Results: Spirulina significantly (p < 0.05) increased Hb in comparison to Placebo (144.1 g/l ± 10.5 Vs 154.5 g/l ± 6.9). After spirulina supplementation, during the 30-min exercise bouts, oxygen uptake and HR were significantly lower (2170 ml/min ± 173 Vs 2311 ml/min ± 189 and 154 bpm ± 14 Vs 149 bpm ± 17), RER was not significantly different. In comparison to placebo, Spirulina significantly increased oxygen uptake at time of fatigue (34.10 ml/min/kg ± 6.03 Vs 37.37 ml/min/kg ± 5.98). Time taken to fatigue was not different. Conclusion: Spirulina supplementation significantly reduces oxygen uptake and HR during arm cycling submaximal exercise, allowing for an increased oxygen uptake during an incremental test to fatigue