ABSTRACT
BACKGROUND: Tennis tournaments often involve playing several consecutive matches interspersed with short periods of recovery. OBJECTIVE: The objective of this study was firstly to assess the impact of several successive tennis matches on the physical performance of competitive players and secondly to evaluate the potential of sports drinks to minimize the fatigue induced by repeated matches. METHODS: This was a crossover, randomized controlled study. Eight male regionally-ranked tennis players participated in this study. Players underwent a series of physical tests to assess their strength, speed, power and endurance following the completion of three tennis matches each of two hours duration played over three consecutive half-days (1.5 day period for each condition). In the first condition the players consumed a sports drink before, during and after each match; in the second, they drank an identical volume of placebo water. The results obtained were compared with the third 'rest' condition in which the subjects did not play any tennis. Main outcomes measured were maximal isometric strength and fatigability of knee and elbow extensors, 20-m sprint speed, jumping height, specific repeated sprint ability test and hand grip strength. RESULTS: The physical test results for the lower limbs showed no significant differences between the three conditions. Conversely, on the upper limbs the EMG data showed greater fatigue of the triceps brachii in the placebo condition compared to the rest condition, while the ingestion of sports drinks attenuated this fatigue. CONCLUSIONS: This study has demonstrated for the first time that, when tennis players are adequately hydrated and ingest balanced meals between matches, then no large drop in physical performance is observed even during consecutive competitive matches. TRIAL REGISTRATION: ClinicalTrials.gov: NCT01353872.
ABSTRACT
OBJECTIVE: To investigate the effect of a natural cholesterol-lowering supplement (NCLS) containing red yeast rice, policosanols and artichoke leaf extracts on blood lipid concentrations as well as on safety parameters when given over 16 weeks in 100 volunteers with untreated moderate hypercholesterolemia, in a randomized, double-blind, placebo-controlled trial. RESULTS: Reduction of primary outcome low-density lipoprotein cholesterol [-0.22 g/L (95% confidence interval, CI: -0.31 to -0.12) corresponding to -14.3% from baseline (95% CI: -21.5 to -7.2) compared to placebo], as well as total cholesterol, apolipoprotein B100 and apolipoprotein B100/apolipoprotein A-I ratio, were observed after 16 weeks of supplementation with NCLS. These effects were already observed at Week 4 and 10 of supplementation. No significant changes were observed in high-density lipoprotein, triacylglycerol, creatine kinase, lactate dehydrogenase and coenzyme Q10 levels, as well as in markers of liver and renal function. CONCLUSIONS: The NCLS was effective in reducing low-density lipoprotein cholesterol and apolipoprotein B100 in subjects with moderate hypercholesterolemia, without modifying safety parameters.
Subject(s)
Apolipoprotein B-100/blood , Biological Products/therapeutic use , Cholesterol, LDL/blood , Cynara scolymus , Fatty Alcohols/therapeutic use , Hypercholesterolemia/drug therapy , Plant Extracts/therapeutic use , Adult , Anticholesteremic Agents/pharmacology , Anticholesteremic Agents/therapeutic use , Apolipoprotein A-I/blood , Biological Products/pharmacology , Cholesterol/blood , Cholesterol, HDL/blood , Dietary Supplements , Double-Blind Method , Fatty Alcohols/pharmacology , Female , Humans , Hypercholesterolemia/blood , Male , Middle Aged , Phytotherapy , Plant Extracts/pharmacology , Triglycerides/bloodABSTRACT
Sports drinks are often used before, during, and after tennis tournaments, but their ability to influence physiological and psychological variables and the characteristics of tennis match play remains uncertain. The objective of this study was to evaluate the impact of ingesting specially formulated pre-exercise, endurance, and recovery sports drinks on glycemia and performance indices during a simulated tennis tournament. Eight well-trained male tennis players performed two 3-match round-robin tennis tournaments although ingesting sports drinks (SPDs) or placebos (PLAs) before, during, and after each match (crossover study design). Before the first tournament, match and drink order were randomized (SPDs or PLAs first) and players were placed under controlled nutritional and hydration conditions. Glycemia, heart rate response, rate of perceived exertion, and notational/match analysis were assessed during each match. Sports drinks maintained higher glycemia levels during match 2 and 3 of the tennis tournament compared with PLAs (p < 0.01). Moreover, higher mean heart rates (p < 0.01) and stroke frequencies (p < 0.01) concomitantly with lower rates of perceived exertion (p < 0.01) were recorded throughout the duration of the tournament, when players used the SPDs. During a 3-match tennis tournament, SPDs allow higher stroke frequency during play, with decreased rates of perceived exertion.
Subject(s)
Athletic Performance/physiology , Beverages , Drinking/physiology , Tennis/physiology , Adult , Blood Glucose/metabolism , Cross-Over Studies , Double-Blind Method , Heart Rate , Humans , Male , Muscle Fatigue , Physical Exertion , Young AdultABSTRACT
PURPOSE: Red yeast rice (RYR), sugar cane-derived policosanols (SCdP) and artichoke leaf extracts (ALEs) are currently incorporated alone or in combination into dietary supplements for their potential low-density-lipoprotein cholesterol (LDL-cholesterol)-lowering effects. Yet, there is no information supporting the efficacy of this association on the reduction in LDL-cholesterol. The main objective of this study was to investigate the effects of a new dietary supplement (DS) with RYR, SCdP and ALEs on LDL-cholesterol. METHODS: In a double-blind, randomized, parallel controlled study, 39 subjects from 21 to 55 years with moderate hypercholesterolemia without drug treatment were assigned to 2 groups and then consumed either a DS containing RYR, SCdP and ALEs or a placebo over a 16-week period. Plasma concentrations of lipids [LDL-cholesterol, total cholesterol (TC), high-density-lipoprotein cholesterol (HDL-cholesterol), triacylglycerols (TG)] and plasma levels of vitamins C and E, total polyphenols and malondialdehyde were determined at baseline and after 4, 8, 12 and 16 weeks. RESULTS: LDL-cholesterol and TC were reduced by, respectively, 21.4 % (95 % CI, -13.3 to -24.9 %, p < 0.001) and 14.1 % (95 % CI, -10.1 to -18.0 %, p < 0.001) at week 16 in the DS group compared with baseline. Similar results were obtained at weeks 4, 8 and 12. TG decreased by 12.2 % after 16 weeks in the DS group (95 % CI: -24.4 to -0.1 %, p < 0.05). For the vitamin E/TC ratio, a difference was observed between groups at week 16 (p < 0.05). Other parameters were not modified. CONCLUSIONS: Daily consumption of this new DS decreased LDL-cholesterol and TC and is therefore an interesting, convenient aid in managing mild to moderate hypercholesterolemia.
Subject(s)
Cholesterol, LDL/blood , Dietary Supplements , Hypercholesterolemia/blood , Hypercholesterolemia/drug therapy , Plant Extracts/administration & dosage , Adult , Anticholesteremic Agents/administration & dosage , Ascorbic Acid/blood , Biological Products/administration & dosage , Cholesterol, HDL/blood , Cynara scolymus/chemistry , Double-Blind Method , Fatty Alcohols/administration & dosage , Female , Humans , Male , Malondialdehyde/blood , Middle Aged , Plant Leaves/chemistry , Polyphenols/blood , Triglycerides/blood , Vitamin E/blood , Young AdultABSTRACT
PURPOSE: To determine the effect of 4 weeks of supplementation, then, withdrawal of a dietary supplement (DS) containing red yeast rice extract, policosanol and artichoke leaf extract at twice the recommended daily dose (6 tablets, 6-TAB) compared to the usual dose (3-TAB) or to a placebo (PLA), on blood lipid profiles and safety biomarkers. METHODS: Forty-five healthy subjects (15 per group), with untreated hypercholesterolaemia, were included in this randomised, double-blind, placebo-controlled clinical trial. RESULTS: After 4 weeks of supplementation, LDL-C was significantly lower in 6-TAB (-0.21 g/l; 95 % CI -0.38 to -0.03 g/l; p = 0.0217) and 3-TAB (-0.25 g/l; 95 % CI -0.42 to -0.07 g/l; p = 0.0071) compared to PLA, although no difference in LDL-cholesterol was observed between the two groups, while no effect was seen on triacylglycerol and HDL-cholesterol. Four weeks after the end of supplementation, no difference in LDL-C was seen between the PLA group and the DS-treated groups. The muscle breakdown biomarkers, as well as biomarkers of liver and renal function, were altered by neither dose of the DS. Acute application of the DS on permeabilised skeletal muscle fibres of rats did not induce deleterious effects on mitochondrial function. CONCLUSIONS: Supplementation with twice the recommended dose of the DS was effective in reducing LDL-cholesterol and appeared safe, but according to the present results, no additional benefit could be achieved compared to the recommended dose.
Subject(s)
Cholesterol, LDL/blood , Dietary Supplements , Hypercholesterolemia/blood , Plant Extracts/administration & dosage , Adolescent , Adult , Aged , Animals , Anticholesteremic Agents/administration & dosage , Biological Products/administration & dosage , Biomarkers/blood , Cholesterol, HDL/blood , Cynara scolymus/chemistry , Double-Blind Method , Endpoint Determination , Fatty Alcohols/administration & dosage , Female , Humans , Hypercholesterolemia/drug therapy , Life Style , Male , Middle Aged , Mitochondria/drug effects , Mitochondria/metabolism , Muscle, Skeletal/drug effects , Muscle, Skeletal/metabolism , Plant Leaves/chemistry , Rats , Rats, Wistar , Recommended Dietary Allowances , Triglycerides/blood , Young AdultABSTRACT
BACKGROUND: A 50-item self-administered food frequency questionnaire (FFQ) was developed for French adults, to assess the intake of energy, 10 macronutrients, 11 vitamins, and 11 minerals, and to be used in the context of a medical consultation. OBJECTIVE: To assess the repeatability and relative validity of this FFQ compared to a 7-day diet record (7-DR). DESIGN: A total of 54 and 100 French adults were included in the repeatability and validation studies, respectively. Repeatability was assessed using two FFQs, the second carried out 3 weeks after the first. In the validation study, subjects first completed the FFQ, then the 7-DR the following week. Energy and nutrient intakes were compared using Pearson correlation. The degree of misclassification by the FFQ, compared to the 7-DR, was calculated by a contingency table of quintiles. Bland-Altman plots assessed the correlation between FFQ and 7-DR across the intake range. RESULTS: Repeatability for intake, explored by Pearson correlation, was 0.62-0.90 (median: 0.81). Relative validity, as determined by Pearson correlation for the nutrient intake derived from the FFQ and 7-DR, was 0.36-0.80 (0.64). The FFQ tended to report higher fiber and micronutrient intake than 7-DR. Misclassification into opposite quintiles ranged 0-6% (1%), whereas classification into same or adjacent quintiles ranged 59-83% (74%). Bland-Altman plots showed good agreement for most nutrients across the range of intake. CONCLUSION: This new FFQ showed a high repeatability and good relative validity, and thanks to its short length, should be a useful tool for rapidly evaluating the nutrient intake of French adults.
ABSTRACT
BACKGROUND: Carbohydrates (CHOs), branched-chain amino acids (BCAAs) and caffeine are known to improve running performance. However, no information is available on the effects of a combination of these ingredients on performance and neuromuscular function during running. METHODS: The present study was designed as a randomized double-blind cross-over placebo-controlled trial. Thirteen trained adult males completed two protocols, each including two conditions: placebo (PLA) and Sports Drink (SPD: CHOs 68.6 g.L-1, BCAAs 4 g.L-1, caffeine 75 mg.L-1). Protocol 1 consisted of an all-out 2 h treadmill run. Total distance run and glycemia were measured. In protocol 2, subjects exercised for 2 h at 95% of their lowest average speeds recorded during protocol 1 (whatever the condition). Glycemia, blood lactate concentration and neuromuscular function were determined immediately before and after exercise. Oxygen consumption (VËO2), heart rate (HR) and rate of perceived exertion (RPE) were recorded during the exercise. Total fluids ingested were 2 L whatever the protocols and conditions. RESULTS: Compared to PLA, ingestion of SPD increased running performance (p = 0.01), maintained glycemia and attenuated central fatigue (p = 0.04), an index of peripheral fatigue (p = 0.04) and RPE (p = 0.006). Maximal voluntary contraction, VËO2, and HR did not differ between the two conditions. CONCLUSIONS: This study showed that ingestion of a combination of CHOs, BCAAs and caffeine increased performance by about 2% during a 2-h treadmill run. The results of neuromuscular function were contrasted: no clear cut effects of SPD were observed. TRIAL REGISTRATION: ClinicalTrials.gov, http://www.clinicaltrials.gov, NCT00799630.