Green tea extract supplementation does not hamper endurance-training adaptation but improves antioxidant capacity in sedentary men

2015 ◽  
Vol 40 (10) ◽  
pp. 990-996 ◽  
Author(s):  
Yu-Chi Kuo ◽  
Jung-Charng Lin ◽  
Jeffrey R. Bernard ◽  
Yi-Hung Liao
Keyword(s):  
Oxygen Uptake ◽  
Antioxidant Capacity ◽  
Endurance Training ◽  
Green Tea ◽  
Acute Exercise ◽  
Green Tea Extract ◽  
Placebo Control ◽  
Endurance Capacity ◽  
Exercise Induced ◽  
Tea Extract

The purpose of this study was to investigate the effect of green tea extract (GTE) supplementation combined with endurance training on endurance capacity and performance in sedentary men. Forty untrained men (age: 20 ± 1 years) participated in this study. Subjects were assigned to 1 of 4 treatments: (i) placebo-control (CTRL), (ii) GTE, (iii) endurance training (Ex), and (iv) endurance training with GTE (ExGTE). During the 4-week intervention, exercise training was prescribed as 75% oxygen uptake reserve for three 20-min sessions per week, and either GTE (250 mg/day) or placebo was provided. Endurance capacity, malondialdehyde (MDA), total antioxidant status (TAS), and creatine kinase (CK) were examined. Ex and ExGTE but not GTE improved exhaustive-run time (Ex: +8.2%, p = 0.031; ExGTE: +14.3%, p < 0.001); in addition, Ex and ExGTE significantly increased maximal oxygen uptake by ∼14% (p = 0.041) and ∼17% (p = 0.017) above the values of the CTRL group, respectively. Both Ex and ExGTE significantly decreased the increase of CK by ∼11%–32% below that of CTRL following an exhaustive run (Ex: p = 0.007; ExGTE: p = 0.001). Moreover, TAS levels increased by ∼11% in ExGTE after training (p = 0.040), and GTE, Ex, and ExGTE markedly attenuated exercise-induced MDA production (p = 0.01, p = 0.005, p = 0.011, respectively). In conclusion, this investigation demonstrated that daily ingestion of GTE during endurance training does not impair improvements in endurance capacity. Moreover, endurance training combined with GTE not only increases antioxidant capacity without attenuating endurance training adaptations, but also further attenuates acute exercise-induced CK release.

Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice

2005 ◽  
Vol 288 (3) ◽  
pp. R708-R715 ◽  
Author(s):  
Takatoshi Murase ◽  
Satoshi Haramizu ◽  
Akira Shimotoyodome ◽  
Azumi Nagasawa ◽  
Ichiro Tokimitsu
Keyword(s):  
Fatty Acid ◽  
Green Tea ◽  
Epigallocatechin Gallate ◽  
Fat Oxidation ◽  
Green Tea Extract ◽  
Endurance Capacity ◽  
Oxidation Activity ◽  
Tea Extract ◽  
High Level ◽  
Dose Dependent

Green tea contains a high level of polyphenolic compounds known as catechins. We investigated the effects of green tea extract (GTE), which is rich in catechins, on endurance capacity, energy metabolism, and fat oxidation in BALB/c mice over a 10-wk period. Swimming times to exhaustion for mice fed 0.2–0.5% (wt/wt) GTE were prolonged by 8–24%. The effects were dose dependent and accompanied by lower respiratory quotients and higher rates of fat oxidation as determined by indirect calorimetry. In addition, feeding with GTE increased the level of β-oxidation activity in skeletal muscle. Plasma lactate concentrations in mice fed GTE were significantly decreased after exercise, concomitant with increases in free fatty acid concentrations in plasma, suggesting an increased lipid use as an energy source in GTE-fed mice. Epigallocatechin gallate (EGCG), a major component of tea catechins, also enhanced endurance capacity, suggesting that the endurance-improving effects of GTE were mediated, at least in part, by EGCG. The β-oxidation activity and the level of fatty acid translocase/CD36 mRNA in the muscle was higher in GTE-fed mice compared with control mice. These results indicate that GTE are beneficial for improving endurance capacity and support the hypothesis that the stimulation of fatty acid use is a promising strategy for improving endurance capacity.

The Effects of EGCG on Fat Oxidation and Endurance Performance in Male Cyclists

2009 ◽  
Vol 19 (6) ◽  
pp. 624-644 ◽  
Author(s):  
Sara Dean ◽  
Andrea Braakhuis ◽  
Carl Paton
Keyword(s):  
Fatty Acids ◽  
Green Tea ◽  
Time Trial ◽  
Endurance Performance ◽  
Fat Oxidation ◽  
Cycling Performance ◽  
Green Tea Extract ◽  
Endurance Capacity ◽  
Caffeine Ingestion ◽  
Tea Extract

Researchers have long been investigating strategies that can increase athletes’ ability to oxidize fatty acids and spare carbohydrate, thus potentially improving endurance capacity. Green-tea extract (epigallocatechin-3-gallate; EGCG) has been shown to improve endurance capacity in mice. If a green-tea extract can stimulate fat oxidation and as a result spare glycogen stores, then athletes may benefit through improved endurance performance. Eight male cyclists completed a study incorporating a 3-way crossover, randomized, placebo-controlled, double-blinded, diet-controlled research design. All participants received 3 different treatments (placebo 270 mg, EGCG 270 mg, and placebo 270 mg + caffeine 3 mg/kg) over a 6-day period and 1 hr before exercise testing. Each participant completed 3 exercise trials consisting of 60 min of cycling at 60% maximum oxygen uptake (VO2max) immediately followed by a self-paced 40-km cycling time trial. The study found little benefit in consuming green-tea extract on fat oxidation or cycling performance, unlike caffeine, which did benefit cycling performance. The physiological responses observed during submaximal cycling after caffeine ingestion were similar to those reported previously, including an increase in heart rate (EGCG 147 ± 17, caffeine 146 ± 19, and placebo 144 ± 15 beats/min), glucose at the 40-min exercise time point (placebo 5.0 ± 0.8, EGCG 5.4 ± 1.0, and caffeine 5.8 ± 1.0 mmol/L), and resting plasma free fatty acids and no change in the amount of carbohydrate and fat being oxidized. Therefore, it was concluded that green-tea extract offers no additional benefit to cyclists over and above those achieved by using caffeine.

Effect of endurance training on muscle TCA cycle metabolism during exercise in humans

2004 ◽  
Vol 97 (2) ◽  
pp. 579-584 ◽  
Author(s):  
Krista R. Howarth ◽  
Paul J. LeBlanc ◽  
George J. F. Heigenhauser ◽  
Martin J. Gibala
Keyword(s):  
Oxygen Uptake ◽  
Endurance Training ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Tca Cycle ◽  
Peak Oxygen Uptake ◽  
Endurance Capacity ◽  
Exercise Induced ◽  
Cycle Endurance ◽  
Pretraining Trial

We tested the theory that links the capacity to perform prolonged exercise with the size of the muscle tricarboxylic acid (TCA) cycle intermediate (TCAI) pool. We hypothesized that endurance training would attenuate the exercise-induced increase in TCAI concentration ([TCAI]); however, the lower [TCAI] would not compromise cycle endurance capacity. Eight men (22 ± 1 yr) cycled at ∼80% of initial peak oxygen uptake before and after 7 wk of training (1 h/day, 5 days/wk). Biopsies (vastus lateralis) were obtained during both trials at rest, after 5 min, and at the point of exhaustion during the pretraining trial (42 ± 6 min). A biopsy was also obtained at the end of exercise during the posttraining trial (91 ± 6 min). In addition to improved performance, training increased ( P < 0.05) peak oxygen uptake and citrate synthase maximal activity. The sum of four measured TCAI was similar between trials at rest but lower after 5 min of exercise posttraining [2.7 ± 0.2 vs. 4.3 ± 0.2 mmol/kg dry wt ( P < 0.05)]. There was a clear dissociation between [TCAI] and endurance capacity because the [TCAI] at the point of exhaustion during the pretraining trial was not different between trials (posttraining: 2.9 ± 0.2 vs. pretraining: 3.5 ± 0.2 mmol/kg dry wt), and yet cycle endurance time more than doubled in the posttraining trial. Training also attenuated the exercise-induced decrease in glutamate concentration (posttraining: 4.5 ± 0.7 vs. pretraining: 7.7 ± 0.6 mmol/kg dry wt) and increase in alanine concentration (posttraining: 3.3 ± 0.2 vs. pretraining: 5.6 ± 0.3 mmol/kg dry wt; P < 0.05), which is consistent with reduced carbon flux through alanine aminotransferase. We conclude that, after aerobic training, cycle endurance capacity is not limited by a decrease in muscle [TCAI].

scholarly journals Green tea extract only affects markers of oxidative status postprandially: lasting antioxidant effect of flavonoid-free diet

2002 ◽  
Vol 87 (4) ◽  
pp. 343-355 ◽  
Author(s):  
J. F. Young ◽  
L. O. Dragsted ◽  
J. Haraldsdóttir ◽  
B. Daneshvar ◽  
M. A. Kall ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Green Tea ◽  
Plasma Lipids ◽  
Daily Intake ◽  
Oxidative Status ◽  
Green Tea Extract ◽  
Long Term Effects ◽  
Plasma Antioxidant Capacity ◽  
Tea Extract ◽  
Plasma Antioxidant

Epidemiological studies suggest that foods rich in flavonoids might reduce the risk of cardiovascular disease and cancer. The objective of the present study was to investigate the effect of green tea extract (GTE) used as a food antioxidant on markers of oxidative status after dietary depletion of flavonoids and catechins. The study was designed as a 2×3 weeks blinded human cross-over intervention study (eight smokers, eight non-smokers) with GTE corresponding to a daily intake of 18·6 mg catechins/d. The GTE was incorporated into meat patties and consumed with a strictly controlled diet otherwise low in flavonoids. GTE intervention increased plasma antioxidant capacity from 1·35 to 1·56 (P<0·02) in postprandially collected plasma, most prominently in smokers. The intervention did not significantly affect markers in fasting blood samples, including plasma or haemoglobin protein oxidation, plasma oxidation lagtime, or activities of the erythrocyte superoxide dismutase, glutathione peroxidase, glutathione reductase and catalase. Neither were fasting plasma triacylglycerol, cholesterol, α-tocopherol, retinol, β-carotene, or ascorbic acid affected by intervention. Urinary 8-oxo-deoxyguanosine excretion was also unaffected. Catechins from the extract were excreted into urine with a half-life of less than 2 h in accordance with the short-term effects on plasma antioxidant capacity. Since no long-term effects of GTE were observed, the study essentially served as a fruit and vegetables depletion study. The overall effect of the 10-week period without dietary fruits and vegetables was a decrease in oxidative damage to DNA, blood proteins, and plasma lipids, concomitantly with marked changes in antioxidative defence.

scholarly journals Effect of green tea extract supplementation on exercise-induced delayed onset muscle soreness and muscular damage

2018 ◽  
Vol 194 ◽  
pp. 77-82 ◽  
Author(s):  
Willian da Silva ◽  
Álvaro S. Machado ◽  
Mauren A. Souza ◽  
Pâmela B. Mello-Carpes ◽  
Felipe P. Carpes
Keyword(s):  
Green Tea ◽  
Muscle Soreness ◽  
Delayed Onset Muscle Soreness ◽  
Green Tea Extract ◽  
Delayed Onset ◽  
Exercise Induced ◽  
Tea Extract ◽  
Muscular Damage

The Effect of Iron and Fat in a Diet Containing Green Tea Extract (Camellia sinensis) on the Antioxidant Capacity of Some Organs and the mRNA Expression of Specific Genes in Mice

2014 ◽  
Vol 17 (11) ◽  
pp. 1232-1238 ◽  
Author(s):  
Antonios E. Koutelidakis ◽  
Dimosthenis Kizis ◽  
Konstantina Argyri ◽  
Alkistis Kyriakou ◽  
Michael Komaitis ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Mrna Expression ◽  
Green Tea ◽  
Camellia Sinensis ◽  
Green Tea Extract ◽  
Tea Extract
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