105 research outputs found

    New Zealand blackcurrant extract improves high-intensity intermittent running performance.

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    New Zealand blackcurrant (BC) intake showed reduced blood lactate during low and moderate intensity cycling and improved 16.1 km cycling time trial performance. We examined the effect of BC on high-intensity intermittent treadmill running and post-running lactate clearance. Thirteen active males (age: 25±4 yrs, stature: 1.82±0.07 m, body mass: 81±14 kg, V̇O2max: 56±4 mL∙kg-1∙min-1, velocity at V̇O2max: 17.6±0.8 km∙h-1, mean±SD) visited the laboratory three times. In the 1st visit, a ramp protocol (0.1 km∙h-1 every 5 sec) was completed to establish V̇O2max and velocity at V̇O2max, and subjects were familiarised with the protocols. In visits 2 and 3, subjects completed an high intensity intermittent running capability test which consisted of six 19 s high-intensity running bouts, each interspersed by 15 s of low-intensity running, followed by 1 minute of rest, this was repeated at increasing speeds, until exhaustion. Prior to visits 2 and 3, subjects consumed either New Zealand BC extract (300 mg∙day-1 CurraNZ™; containing 105 mg anthocyanin) or placebo (P) (300 mg∙day-1 microcrystalline cellulose M102) for 7 days in capsules (double blind, randomised, cross-over design, wash-out at least 14 days). Blood lactate was collected for 30 min post-exhaustion. Two-tailed paired t-tests were used and significance accepted at p< .05. BC increased total running distance by 10.6% (BC: 4282±833 m, P: 3871±622 m, p = .023, 10 out of 13 subjects improved), with the distance during the high-intensity running bouts by 10.8% (p= .024). Heart rate, rating of perceived exertion and oxygen uptake were not different between conditions for each stage. At exhaustion, lactate tended to be higher for BC (BC: 6.01±1.07 mmol∙L-1, P: 5.22±1.52 mmol∙L-1, p = .066, 9 out of 13 subjects). There was a trend towards improved lactate clearance following 15 min (BC: -2.89±0.51 mmol∙L-1, P: -2.46±0.39 mmol∙L-1, p = .07) and 30 minutes of passive recovery (BC: -4.12±0.73 mmol∙L-1, P: -3.66±1.01 mmol∙L-1, p = 0.11). It is concluded that New Zealand blackcurrant extract (CurraNZ™) may enhance performance in team sports characterised by high-intensity intermittent exercise as with BC intake greater distances were covered during high-intensity running, there was higher lactate tolerance, and increased lactate clearance after high-intensity exercise

    Anthocyanin-Rich Supplementation: Emerging Evidence of Strong Potential for Sport and Exercise Nutrition

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    Dark-coloured fruits, especially berries, have abundant presence of the polyphenol anthocyanin which have been show to provide health benefits. Studies with the berry blackcurrant have provided notable observations with application for athletes and physically active individuals. Alterations in exercise-induced substrate oxidation, exercise performance of repeated high-intensity running and cycling time-trial and cardiovascular function at rest and during exercise were observed with intake of New Zealand blackcurrant. The dynamic plasma bioavailability of the blackcurrant anthocyanins and the anthocyanin-derived metabolites must have changed cell function to provide meaningful in-vivo physiological effects. This perspective will reflect on the research studies for obtaining the applied in-vivo effects by intake of anthocyanin-rich supplementation, the issue of individual responses, and the emerging strong potential of anthocyanins for sport and exercise nutrition. Future work with repeated intake of known amount and type of anthocyanins, gut microbiota handling of anthocyanins, and coinciding measurements of plasma anthocyanin and anthocyanin-derived metabolites and in-vivo cell function will be required to inform our understanding for the unique potential of anthocyanins as a nutritional ergogenic aid for delivering meaningful effects for a wide range of athletes and physically active individuals

    Carbohydrate vs protein supplementation for recovery of neuromuscular function following prolonged load carriage

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    <p>Abstract</p> <p>Background</p> <p>This study examined the effect of carbohydrate and whey protein supplements on recovery of neuromuscular function after prolonged load carriage.</p> <p>Methods</p> <p>Ten male participants (body mass: 81.5 ± 10.5 kg, age: 28 ± 9 years, <inline-formula><graphic file="1550-2783-7-2-i1.gif"/></inline-formula> O<sub>2</sub>max: 55.0 ± 5.5 ml·kg<sup>-1</sup>·min<sup>-1</sup>) completed three treadmill walking tests (2 hr, 6.5 km·h<sup>-1</sup>), carrying a 25 kg backpack consuming 500 ml of either: (1) Placebo (flavoured water) [PLA], (2) 6.4% Carbohydrate Solution [CHO] or (3) 7.0% Whey Protein Solution [PRO]. For three days after load carriage, participants consumed two 500 ml supplement boluses. Muscle performance was measured before and at 0, 24, 48 and 72 h after load carriage, during voluntary and electrically stimulated contractions.</p> <p>Results</p> <p>Isometric knee extension force decreased immediately after load carriage with no difference between conditions. During recovery, isometric force returned to pre-exercise values at 48 h for CHO and PRO but at 72 h for PLA. Voluntary activation decreased immediately after load carriage and returned to pre-exercise values at 24 h in all conditions (<it>P </it>= 0.086). During recovery, there were no differences between conditions for the change in isokinetic peak torque. Following reductions immediately after load carriage, knee extensor and flexor peak torque (60°·s<sup>-1</sup>) recovered to pre-exercise values at 72 h. Trunk extensor and flexor peak torque (15°·s<sup>-1</sup>) recovered to pre-exercise values at 24 h (<it>P </it>= 0.091) and 48 h (<it>P </it>= 0.177), respectively.</p> <p>Conclusion</p> <p>Recovery of neuromuscular function after prolonged load carriage is improved with either carbohydrate or whey protein supplementation for isometric contractions but not for isokinetic contractions.</p

    Acute Effects of New Zealand Blackcurrant Extract on Cycling Time-Trial Are Performance Dependent in Endurance-Trained Cyclists: A Home-Based Study

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    The intake of anthocyanin-rich New Zealand blackcurrant (NZBC) extract (300 mg per day) over a week enhanced 16.1 km cycling time trial (TT) performance in endurance-trained cyclists without acute performance effects. In the present study, the acute effects of an intake of 900 mg of NZBC extract 2 h before performing the 16.1 km cycling TT were examined. A total of 34 cyclists (26 males; 8 females) (age: 38 ± 7 years, V˙O2max: 57 ± 5 mL·kg−1·min−1) completed 4 16.1 km TTs (2 familiarization and 2 experimental trials) over 4 mornings on a home turbo-trainer connected with the online training simulator ZWIFT. There was no difference in time to complete the 16.1 km TT between conditions (placebo: 1422 ± 104 s; NZBC extract: 1414 ± 93 s, p = 0.07). However, when participants were split between faster (1400 s; 7 females; 10 males) cyclists based on average familiarization TTs, a difference in TT performance was observed only in the slower group (placebo: 1499 ± 91 s; NZBC extract: 1479 ± 83 s, p = 0.02). At 12 km (quartile analysis), power output (p = 0.04) and speed (p = 0.04) were higher compared to the placebo with no effects on heart rate and cadence. The acute effects of 900 mg of NZBC extract on a 16.1 km cycling time-trial may depend on the performance ability of male endurance-trained cyclists. More work is needed to address whether there is a sex-specific time-trial effect of NZBC extract independent of performance ability

    Food for thought: Dietary nootropics for the optimisation of military operators cognitive performance

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    Nootropics are compounds that enhance cognitive performance and have been highlighted as a medium-term human augmentation technology that could support soldier performance. Given the differing ethical, safety, and legal considerations associated with the pharmaceutical subset of nootropics, this analysis focuses on dietary supplementation which may enhance cognition during training and operations. Numerous supplements have been investigated as possible nootropics, however research is often not context specific or of high quality, leading to questions regarding efficacy. There are many other complex cofactors that may affect the efficacy of any dietary nootropic supplement which is designed to improve cognition, such as external stressors (e.g., sleep deprivation, high physical workloads), task specifics (e.g., cognitive processes required), and other psychological constructs (e.g., placebo/nocebo effect). Moreover, military population considerations, such as prior nutritional knowledge and current supplement consumption (e.g., caffeine), along with other issues such as supplement contamination should be evaluated when considering dietary nootropic use within military populations. However, given the increasing requirement for cognitive capabilities by military personnel to complete role-related tasks, dietary nootropics could be highly beneficial in specific contexts. Whilst current evidence is broadly weak, nutritional nootropic supplements may be of most use to the military end user, during periods of high military specific stress. Currently, caffeine and L-tyrosine are the leading nootropic supplements candidates within the military context. Future military specific research on nootropics should be of high quality and use externally valid methodologies to maximise the translation of research to practice

    The effect of sex, menstrual cycle phase and oral contraceptive use on intestinal permeability and ex-vivo monocyte TNFα release following treatment with lipopolysaccharide and hyperthermia

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    Investigate the impact of sex, menstrual cycle phase and oral contraceptive use on intestinal permeability and ex-vivo tumour necrosis factor alpha (TNFα) release following treatment with lipopolysaccharide (LPS) and hyperthermia. Twenty-seven participants (9 men, 9 eumenorrheic women (MC) and 9 women taking an oral contraceptive pill (OC)) completed three trials. Men were tested on 3 occasions over 6 weeks; MC during early-follicular, ovulation, and mid-luteal phases; OC during the pill and pill-free phase. Intestinal permeability was assessed following a 4-hour dual sugar absorption test (lactulose: rhamnose). Venous blood was collected each trial and stimulated with 100 μg·mL LPS before incubation at 37 °C and 40 °C and analysed for TNFα via ELISA. L:R ratio was higher in OC than MC (+0.003, p = 0.061) and men (+0.005, p = 0.007). Men had higher TNFα responses than both MC (+53 %, p = 0.004) and OC (+61 %, p = 0.003). TNFα release was greater at 40 °C than 37 °C (+23 %, p < 0.001). Men present with lower resting intestinal barrier permeability relative to women regardless of OC use and displayed greater monocyte TNFα release following whole blood treatment with LPS and hyperthermia. Oral contraceptive users had highest intestinal permeability however, neither permeability or TNFα release were impacted by the pill cycle. Although no statistical effect was seen in the menstrual cycle, intestinal permeability and TNFα release were more variable across the phases

    No effect of New Zealand blackcurrant extract on recovery of muscle damage following running a half-marathon

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    New Zealand blackcurrant (NZBC) contains anthocyanins, known to moderate blood flow and display anti-inflammatory properties that may improve recovery from exercise-induced muscle damage. The authors examined whether NZBC extract supplementation enhances recovery from exercise-induced muscle damage after a half-marathon race. Following a randomized, double-blind, independent groups design, 20 (eight women) recreational runners (age 30 ± 6 years, height 1.73 ± 0.74 m, body mass 68.5 ± 7.8 kg, half-marathon finishing time 1:56:33 ± 0:18:08 hr:min:s) ingested either two 300-mg/day capsules of NZBC extract (CurraNZ™) or a visually matched placebo, for 7 days prior to and 2 days following a half-marathon. Countermovement jump performance variables, urine interleukin-6, and perceived muscle soreness and fatigue were measured pre, post, and at 24 and 48 hr after the half-marathon and analyzed using a mixed linear model with statistical significance set a priori at p  .05). Urine interleukin-6 increased 48-hr post-half-marathon in the NZBC group only (p  .05). Perceived muscle soreness and fatigue increased immediately post-half-marathon (p  .05). Supplementation with NZBC extract had no effect on the recovery of countermovement jump variables and perceptions of muscle soreness or fatigue following a half-marathon in recreational runners

    Effect of New Zealand Blackcurrant Extract on Isometric Contraction-Induced Fatigue and Recovery: Potential Muscle-Fiber Specific Effects

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    New Zealand blackcurrant (NZBC) extract has shown performance-enhancing effects during cycling, running and sport climbing. We examined effects of NZBC extract on (1) voluntary and twitch force of the quadriceps femoris muscles during repeated isometric contraction-induced fatigue, (2) twitch force during recovery and (3) muscle fiber-specific effects. Familiarized recreationally active males (n = 12, age: 24 ± 5 yrs; height: 180 ± 5 cm; body mass: 89 ± 11 kg) performed sixteen, 5-s voluntary maximal isometric contractions (iMVC) separated by 3-s rest. Twitch force was recorded before, during the 3-s rests and 5-min recovery. Supplementation consisted of 7-days intake of NZBC extract (600 mg∙day−1 containing 210 mg anthocyanin) in a double-blind, randomized, placebo-controlled crossover design with a 14-days washout. NZBC extract allowed for greater force in the first quartile of the iMVCs. Twitch force at baseline was 12% higher with NZBC extract (p = 0.05). However, there was no effect of NZBC for twitch force during the 16-iMVCs and recovery. Based on the maximum post-activation potentiation during the placebo 16-iMVCs, four subjects were classified of having a predominant type I or II muscle fiber typology. In type II, NZBC extract provided a trend for increased MVC force (~14%) in the first quartile and for type I in the fourth quartile (~10%). In type I, NZBC extract seemed to have higher twitch forces during the fatiguing exercise protocol and recovery, indicating increased fatigue resistance. New Zealand blackcurrant extract affects force during repeated maximal isometric contractions. Future work on mechanisms by NZBC extract for muscle fiber-specific fatigue-induced force responses is warranted
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