RESEARCH PROJECT : STUDY LEADER : DR CHRISTA JANSE VAN RENSBURG (Supplements used for racing and cycling performance)
Database: Ovid MEDLINE(R) <1996 to November Week 3 2009>
Search Strategy:
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1 Bicycling/ (3845)
2 (race$ or racing).tw. (39973)
3 exp dietary supplementation/ or supplement$.tw. (98231)
4 1 and 2 and 3 (14)
5 limit 4 to english language (13)
6 exp athletic performance/ (7962)
7 1 and 3 and 6 (72)
8 limit 7 to english language (69)
9 *Bicycling/ and exp *athletic performance/ and 8 (39)
10 5 or 9 (46)
11 limit 10 to yr="1999 -Current" (41)
12 from 11 keep 1-41 (41)
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Result <1>
Unique Identifier
16604129
Status
MEDLINE
Authors
Delattre E. Garcin M. Mille-Hamard L. Billat V.
Authors Full Name
Delattre, Emmanuelle. Garcin, Murielle. Mille-Hamard, Laurence. Billat, Veronique.
Institution
Laboratoire d'Etudes de la Motrcite Humaine, Faculte des Sciences du Sport et de l'Education Physique, Universite de Lille 2, 59790 Ronche, France.
Title
Objective and subjective analysis of the training content in young cyclists.
Source
Applied Physiology, Nutrition, & Metabolism = Physiologie Appliquee, Nutrition et Metabolisme. 31(2):118-25, 2006 Apr.
Abstract
The purpose of this study was to analyse the objective and subjective training for young cyclists that is prescribed by their coaches. Seven cyclists performed an incremental exercise to exhaustion before and after 14 weeks of training using an incremental test to determine their maximal oxygen uptake (VO(2) (max)), the velocity associated with VO(2) (max) (vVO(2) (max)), and the velocity associated with the ventilatory threshold (vVT). Cyclists completed a training record with the actual content and the perceived exertion of each training session during these 14 weeks. We have focused on the actual content of the training prescribed by the coaches. Analysis of the content of each session allowed us to calculate the objective training load (volume at different intensities) and to determine the subjective training load from perceived exertion ratings (training load, monotony, strain, and fitness-fatigue). The results showed that cyclists were training at a relatively low in!
tensity and that training rating of perceived exhaustion was weak. Moreover, after 14 weeks of training, VO2 max did not change whereas vVO(2) (max) and vVT increased significantly. Therefore, a discrepancy may exist between what is perceived during training and the effects of training. Consequently, objective and subjective indices collected from training books provided useful information supplementary to that recorded from the physiological indices alone.
Publication Type
Comparative Study. Journal Article. Research Support, Non-U.S. Gov't.
Result <2>
Unique Identifier
16505084
Status
MEDLINE
Authors
Hew-Butler TD. Sharwood K. Collins M. Speedy D. Noakes T.
Authors Full Name
Hew-Butler, T D. Sharwood, K. Collins, M. Speedy, D. Noakes, T.
Institution
University of Cape Town, Newlands, Cape Town, South Africa.
Title
Sodium supplementation is not required to maintain serum sodium concentrations during an Ironman triathlon.
Source
British Journal of Sports Medicine. 40(3):255-9, 2006 Mar.
Abstract
CONTEXT: Critical assessment of recommendations that athletes consume additional sodium during athletic events. OBJECTIVE: To evaluate if sodium supplementation is necessary to maintain serum sodium concentrations during prolonged endurance activity and prevent the development of hyponatraemia. DESIGN: Prospective randomised trial of athletes receiving sodium (620 mg table salt), placebo (596 mg starch), or no supplementation during a triathlon. The sodium and placebo tablets were taken ad libitum, with the suggested range of 1-4 per hour. SETTING: The 2001 Cape Town Ironman triathlon (3.8 km swim, 180 km cycle, 42.2 km run). SUBJECTS: A total of 413 triathletes completing the Ironman race. MAIN OUTCOME MEASURES: Sodium supplementation was not necessary to maintain serum sodium concentrations in athletes completing an Ironman triathlon nor required to prevent hyponatraemia from occurring in athletes who did not ingest supplemental sodium during the race. RESULTS: Subjects !
in the sodium supplementation group ingested an additional 3.6 (2.0) g (156 (88) mmol) sodium during the race (all values are mean (SD)). There were no significant differences between the sodium, placebo, and no supplementation groups with regard to age, finishing time, serum sodium concentration before and after the race, weight before the race, weight change during the race, and rectal temperature, systolic and diastolic blood pressure after the race. The sodium supplementation group consumed 14.7 (8.3) tablets, and the placebo group took 15.8 (10.1) tablets (p = 0.55; NS). CONCLUSIONS: Ad libitum sodium supplementation was not necessary to preserve serum sodium concentrations in athletes competing for about 12 hours in an Ironman triathlon. The Institute of Medicine's recommended daily adequate intake of sodium (1.5 g/65 mmol) seems sufficient for a healthy person without further need to supplement during athletic activity.
Publication Type
Journal Article. Randomized Controlled Trial.
Result <3>
Unique Identifier
12394199
Status
MEDLINE
Authors
Speedy DB. Thompson JM. Rodgers I. Collins M. Sharwood K. Noakes TD.
Authors Full Name
Speedy, Dale B. Thompson, John M D. Rodgers, Ian. Collins, Malcolm. Sharwood, Karen. Noakes, Timothy D.
Institution
Department of General Practice and Primary Care, University of Auckland, New Zealand.
Title
Oral salt supplementation during ultradistance exercise.[erratum appears in Clin J Sport Med. 2003 Jan;13(1):67.].
Source
Clinical Journal of Sport Medicine. 12(5):279-84, 2002 Sep.
Abstract
OBJECTIVE: The objective of this study was to determine whether sodium supplementation 1) influences changes in body weight, serum sodium [Na], and plasma volume (PV), and 2) prevents hyponatremia in Ironman triathletes. SETTING: The study was carried out at the South African Ironman triathlon. PARTICIPANTS: Thirty-eight athletes competing in the triathlon were given salt tablets to ingest during the race. Data collected from these athletes [salt intake group (SI)] were compared with data from athletes not given salt [no salt group (NS)]. INTERVENTIONS: Salt tablets were given to the SI group to provide approximately 700 mg/h of sodium. MAIN OUTCOME MEASUREMENTS: Serum sodium, hemoglobin, and hematocrit were measured at race registration and after the race. Weights were measured before and after the race. Members of SI were retrospectively matched to subjects in NS for 1) weight change and 2) pre-race [Na]. RESULTS: The SI group developed a 3.3-kg weight loss (p < 0.0001) !
and significantly increased their [Na] (delta[Na] 1.52 mmol/L; p = 0.005). When matched for weight change during the race, SI increased their [Na] compared with NS (mean 1.52 versus 0.04 mmol/L), but this did not reach statistical significance (p = 0.08). When matched for pre-race [Na], SI had a significantly smaller percent body weight loss than NS (-4.3% versus -5.1%; p = 0.04). There was no significant difference in the increase of [Na] in both groups (1.57 versus 0.84 mmol/L). PV increased equally in both groups. None of the subjects finished the race with [Na] < 135 mmol/L. CONCLUSIONS: Sodium ingestion was associated with a decrease in the extent of weight loss during the race. There was no evidence that sodium ingestion significantly influenced changes in [Na] or PV more than fluid replacement alone in the Ironman triathletes in this study. Sodium supplementation was not necessary to prevent the development of hyponatremia in these athletes who lost weight, indicatin!
g that they had only partially replaced their fluid and other losses d
uring the Ironman triathlon.
Publication Type
Clinical Trial. Controlled Clinical Trial. Journal Article.
Result <4>
Unique Identifier
19584605
Status
MEDLINE
Authors
Jeukendrup A. Tipton KD.
Authors Full Name
Jeukendrup, Asker. Tipton, Kevin D.
Institution
School of Sport and Exercise Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.
Title
Legal nutritional boosting for cycling. [Review] [45 refs]
Source
Current Sports Medicine Reports. 8(4):186-91, 2009 Jul-Aug.
Abstract
Several nutritional strategies have been used in cycling to improve performance. Carbohydrate feeding during exercise has been shown to be effective, but recent studies have suggested that recommendations may have to be adjusted to take into account recent findings. Protein co-ingested with carbohydrate during exercise has received a lot of recent interest, but the evidence is equivocal, at best. Thus, in the absence of a plausible mechanism, it is difficult to see how protein would increase endurance performance. There also has been a lot of interest in training with low glycogen to maximize training adaptations, but the longer-term effects upon performance are still unclear. Various supplements have been suggested to improve endurance performance, but most of these nutrition supplements lack the scientific support that would warrant the recommendation. [References: 45]
Publication Type
Journal Article. Review.
Result <5>
Unique Identifier
16685547
Status
MEDLINE
Authors
Davison G. Gleeson M.
Authors Full Name
Davison, Glen. Gleeson, Michael.
Institution
School of Sport and Exercise Sciences, Loughborough University, Loughborough, Leicestershire LE11 3TU, UK.
Title
The effect of 2 weeks vitamin C supplementation on immunoendocrine responses to 2.5 h cycling exercise in man.[see comment].
Comments
Comment in: Eur J Appl Physiol. 2007 Apr;99(6):707-8; PMID: 17219167
Source
European Journal of Applied Physiology. 97(4):454-61, 2006 Jul.
Abstract
An increased systemic concentration of stress hormones (of the hypothalamic-pituitary adrenal axis) and some cytokines may contribute to the depression of immune cell function typically observed after prolonged exercise. The aim of the present study was to determine the effect of 2 weeks of supplementation with vitamin C (VC) on cortisol, adrenocorticotrophic hormone, interleukin-6, oxidative stress and neutrophil responses to a single bout of endurance exercise. Nine healthy endurance-trained males exercised for 2.5 h at 60% VO2max after 2 weeks of placebo (PLA) or VC (1,000 mg day(-1)) supplementation. All participants completed both trials utilising a randomised crossover design with a minimum 14 day washout period between trials. There was a significant trial x time interaction effect for plasma cortisol concentration (P = 0.039) which tended to be lower in the VC trial but post hoc analysis found no specific between trial differences. There was a significantly lower p!
ost-exercise neutrophilia (P < 0.014) in the VC trial, compared with the PLA trial. There was no trial x time interaction for measures of neutrophil function (bacteria-stimulated elastase release, fMLP or PMA-stimulated oxidative burst). However, there was a trend for higher fMLP-stimulated neutrophil oxidative burst in the VC compared with PLA trial (trial x time interaction, P = 0.075). These results suggest that supplementation with VC for a period of up to 2 weeks provides little to no protection against the depression of neutrophil function which typically occurs after endurance exercise.
Publication Type
Clinical Trial. Journal Article. Randomized Controlled Trial.
Result <6>
Unique Identifier
17928803
Status
MEDLINE
Authors
Stannard SR. Hawke EJ. Schnell N.
Authors Full Name
Stannard, S R. Hawke, E J. Schnell, N.
Institution
Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand.
Title
The effect of galactose supplementation on endurance cycling performance.
Source
European Journal of Clinical Nutrition. 63(2):209-14, 2009 Feb.
Abstract
OBJECTIVES: This study tested the hypothesis that supplementation with galactose before and during endurance exercise would spare carbohydrate (CHO), optimize fat utilization and improve performance compared with a typical sports drink formulation. SUBJECTS: Nine well-trained cyclists undertook three trials, each consisting of 120 min at 65 VO(2max) followed immediately by a set work, self-paced time trial (TT). Three treatments, allocated as a randomized balanced design, consisted of the following: (a) 8% (w/w) solution of galactose (Gal); (b) 8% solution of 50% galactose/50% glucose (Gluc/Gal); and (c) 8% solution of 80% glucose/20% fructose (Gluc/Fru). These were consumed as 0.67 g CHO per kg body wt 45-min pre-exercise; 1.0 g CHO per kg body wt per h for the first 120 min of exercise; 0.33 g CHO per kg body wt during the TT. Blood samples were collected before and during exercise; respiratory gas samples were collected only during fixed workload exercise. RESULTS: Mean!
TT power output was significantly less in Gal compared with Gluc/Gal (P=0.030). Blood glucose and insulin concentrations were lower, and free fatty acids higher in Gal compared with Gluc/Gal and Gluc/Fru. Respiratory exchange ratio was not significantly different between trials. CONCLUSIONS: Ingestion of an 8% galactose-only solution (12.5 ml per kg body wt per h) is detrimental to endurance performance compared with equivalent volumes of iso-osmotic solutions containing 50% galactose/50% glucose or 80% glucose/20% fructose. This may reflect the inability of the liver to convert galactose into glucose at a rate required to support strenuous exercise intensity.
Publication Type
Journal Article. Randomized Controlled Trial. Research Support, Non-U.S. Gov't.
Result <7>
Unique Identifier
19585317
Status
MEDLINE
Authors
Sureda A. Cordova A. Ferrer MD. Tauler P. Perez G. Tur JA. Pons A.
Authors Full Name
Sureda, Antoni. Cordova, Alfredo. Ferrer, Miguel D. Tauler, Pedro. Perez, Gerardo. Tur, Josep A. Pons, Antoni.
Institution
Laboratori de Ciencies de l'Activitat Fisica, Departament de Biologia Fonamental i Ciencies de la Salut, Universitat de les Illes Balears, Palma de Mallorca, Illes Balears, Spain.
Title
Effects of L-citrulline oral supplementation on polymorphonuclear neutrophils oxidative burst and nitric oxide production after exercise.
Source
Free Radical Research. 43(9):828-35, 2009 Sep.
Abstract
Seventeen volunteer male professional cyclists were randomly assigned to control or supplemented (6 g L-citrulline-malate) groups and participated in a cycling stage. Blood samples were taken in basal conditions, after the race and 3 h post-race. Citrulline supplementation significantly increased plasma concentration of both arginine and citrulline after the stage only in the supplemented group. Polymorphonuclear neutrophils (PMNs) from controls responded to exercise with a progressive decrease in ROS production. Supplemented PMNs significantly increased ROS production after exercise compared to basal values and diminished to values lower than basal at recovery. PMN nitrite concentration was significantly higher after exercise and recovery only in the supplemented group. Markers of oxidative damage-CK, LDH, malondialdehyde-and DNA damage remained unchanged in both groups. In conclusion, oral L-citrulline administration previous to a cycling stage increases plasma arginine !
availability for NO synthesis and PMNs priming for oxidative burst without oxidative damage.
Publication Type
Journal Article. Randomized Controlled Trial. Research Support, Non-U.S. Gov't.
Result <8>
Unique Identifier
19403954
Status
MEDLINE
Authors
Ivy JL. Kammer L. Ding Z. Wang B. Bernard JR. Liao YH. Hwang J.
Authors Full Name
Ivy, John L. Kammer, Lynne. Ding, Zhenping. Wang, Bei. Bernard, Jeffrey R. Liao, Yi-Hung. Hwang, Jungyun.
Institution
Department of Kinesiology and Health Education, University of Texas, Austin, TX 78712-0360, USA.
Title
Improved cycling time-trial performance after ingestion of a caffeine energy drink.
Source
International Journal of Sport Nutrition & Exercise Metabolism. 19(1):61-78, 2009 Feb.
Abstract
CONTEXT: Not all athletic competitions lend themselves to supplementation during the actual event, underscoring the importance of preexercise supplementation to extend endurance and improve exercise performance. Energy drinks are composed of ingredients that have been found to increase endurance and improve physical performance. PURPOSE: The purpose of the study was to investigate the effects of a commercially available energy drink, ingested before exercise, on endurance performance. METHODS: The study was a double-blind, randomized, crossover design. After a 12-hr fast, 6 male and 6 female trained cyclists (mean age 27.3 +/- 1.7 yr, mass 68.9 +/- 3.2 kg, and VO2 54.9 +/- 2.3 ml x kg-1 x min-1) consumed 500 ml of either flavored placebo or Red Bull Energy Drink (ED; 2.0 g taurine, 1.2 g glucuronolactone, 160 mg caffeine, 54 g carbohydrate, 40 mg niacin, 10 mg pantothenic acid, 10 mg vitamin B6, and 10 microg vitamin B12) 40 min before a simulated cycling time trial. Perfo!
rmance was measured as time to complete a standardized amount of work equal to 1 hr of cycling at 70% Wmax. RESULTS: Performance improved with ED compared with placebo (3,690 +/- 64 s vs. 3,874 +/- 93 s, p < .01), but there was no difference in rating of perceived exertion between treatments. b-Endorphin levels increased during exercise, with the increase for ED approaching significance over placebo (p = .10). Substrate utilization, as measured by open-circuit spirometry, did not differ between treatments. CONCLUSION: These results demonstrate that consuming a commercially available ED before exercise can improve endurance performance and that this improvement might be in part the result of increased effort without a concomitant increase in perceived exertion.
Publication Type
Journal Article. Randomized Controlled Trial. Research Support, Non-U.S. Gov't.
Result <9>
Unique Identifier
19164827
Status
MEDLINE
Authors
Havemann L. Goedecke JH.
Authors Full Name
Havemann, Lize. Goedecke, Julia H.
Institution
UCT/MRC Research Unit for Exercise Science and Sports Medicine, Department of Human Biology, University of Cape Town, Newlands, South Africa.
Title
Nutritional practices of male cyclists before and during an ultraendurance event.
Source
International Journal of Sport Nutrition & Exercise Metabolism. 18(6):551-66, 2008 Dec.
Abstract
The aim of the study was to investigate the pre- and during-race nutritional intake of cyclists competing in a 210-km 1-day ultraendurance cycle race. Forty-five endurance-trained male cyclists participated in this dietary survey and completed a 3-day dietary record. Mean reported carbohydrate (CHO) intake over the 3 days before the race (5.6 +/- 1.7 g/kg) was below the recommended guidelines of 7-10 g/kg. Although 57% of participants indicated that they CHO loaded 1-3 days before the race, only 23% of these participants achieved CHO intakes of > or =7 g/kg over the 3-day period before the race, demonstrating a discrepancy between perceived and actual intakes of CHO. Most participants indicated the use of CHO supplements before (84%) and during (98%) the race and achieved a CHO intake of 63 +/- 23 g/hr during the race. Although most cyclists failed to meet recommended prerace CHO intakes, most achieved the recommended CHO intakes during the race.
Publication Type
Journal Article.
Result <10>
Unique Identifier
18458358
Status
MEDLINE
Authors
Walter AA. Smith AE. Herda TJ. Ryan ED. Moon JR. Cramer JT. Stout JR.
Authors Full Name
Walter, Ashley A. Smith, Abbie E. Herda, Trent J. Ryan, Eric D. Moon, Jordan R. Cramer, Joel T. Stout, Jeffrey R.
Institution
Department of Health and Exercise Science, University of Oklahoma, Norman, OK, USA.
Title
Effects of creatine loading on electromyographic fatigue threshold in cycle ergometry in college-age men.
Source
International Journal of Sport Nutrition & Exercise Metabolism. 18(2):142-51, 2008 Apr.