Background: Watermelon is a rich natural source of l-citrulline. This non-essential amino acid increases exercise performance.
Objective: Evaluate the effect of Fashion watermelon juice enriched in ...l-citrulline (CWJ) (3.45 g per 500 mL) in physical performance and biochemical markers after a half-marathon race.
Design: A randomised, double blind, crossover design where 2 h after drinking 500 mL of CWJ or placebo (PLA, beverage without l-citrulline) amateur male runners performed two half-marathon races. Jump height, heart rate and rating of perceived exertion were evaluated before and after the races. Moreover, muscle soreness and plasma markers of muscle damage and metabolism were evaluated for 72 h after the races.
Results: Muscle soreness perception was significantly lower from 24 to 72 h after the race with CWJ beverage. Immediately after the races, runners under CWJ condition showed plasma lactate and glucose concentrations significantly lower and higher lactate dehydrogenase and l-arginine concentration than runners under PLA. A maintenance of jump heights after the races under CWJ supplementation was found, decreasing significantly with PLA.
Conclusion: A single Fashion watermelon juice enriched in l-citrulline dose diminished muscle soreness perception from 24 to 72 h after the race and maintained lower concentrations of plasma lactate after an exhausting exercise.
Background: The beneficial properties of tea polyphenols have been extensively studied; however, less attention has been paid to their effects, especially anti-inflammatory effect during exhaustive ...exercise.
Objective: The present study assessed the potential protective effects of tea polyphenols against the fatigue, inflammation and tissue injury caused by an exhaustive exercise bout in rats.
Design: Twenty-four healthy male rats were divided into three groups. Group C was a sedentary control group, Groups E+TP and Group E performed a single exhaustive swimming test; all groups had normal diets, but Group E+TP was supplemented with tea polyphenols. All rats were immediately euthanized after exhaustive exercise, and biochemical and inflammatory parameters, including lactic acid (LA), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-10 (IL-10), lactic dehydrogenase (LDH), and creatine kinase (CK) activity levels, were measured. Reverse transcription (RT) and Real-Time PCR was employed to evaluate the mRNA expression of IL-1β in the liver.
Results: The results showed a decrease in serum LA levels (22%, p < 0.05) in rats that consumed dietary tea polyphenols. Interestingly, dietary tea polyphenols decreased the serum levels of pro-inflammatory factors (TNF-α: 13%, p < 0.05; IL-1β: 10%, p < 0.05; and IL-6: 48%, p < 0.05) and shifted the serum IL-10/TNF-α ratio to a predominantly anti-inflammatory milieu (0.52 ± 0.07 vs. 0.67 ± 0.10, p < 0.01). Furthermore, the polyphenols effectively inhibited the release of tissue damage markers (CK: 24%, p < 0.05 and LDH: 28%, p < 0.05) in the serum and decreased IL-1β mRNA expression in the liver.
Conclusions: This study indicated that tea polyphenols could significantly protect rats from the fatigue, inflammation and tissue damage induced by acute exhaustive exercise.
Studien undersøker forskjeller i gutters og jenters treningsmotiver og hvorvidt de velger å delta i idrettslag, treningssentre eller egentrening. Tidligere forskning viser at ungdommens ...treningsmønstre går i retning av det modernitetsteoretikere betegner som individualisering. Det er i liten grad undersøkt hvordan denne individualiseringen er kjønnet. Artikkelens utgangspunkt er de landsrepresentative Ungdataundersøkelsene 2010-2018 med respondenter i aldersgruppen 13-18 år. Resultatene peker på et helseorientert, individualisert og kjønnsdelt treningsfelt. God helse er det mest vektlagte treningsmotivet, og dette er tydeligst for jenter som trener utenfor idrettslag. Å ikke forplikte seg til faste treninger er den viktigste begrunnelsen for å slutte i idrettslag, særlig for eldre tenåringsjenter. Mens konkurranse- og prestasjonsmotiver dominerer blant gutter med økende alder, avtar de for jenter. En høyere andel gutter enn jenter trener i idrettslag, mens jentene foretrekker kommersielle treningssentre. Med utgangspunkt i Giddens’ refleksivitetstese og Bourdieus habitusbegrep, diskuterer vi hvordan forskjeller i treningsmotiver kan forklares som uttrykk for kjønnede identitetsprosjekter og kjønnshabitus. Dette bidrar i neste omgang til å forstå kjønnsforskjeller i treningsorganisering.
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