Composite versus single transportable carbohydrate solution enhances race and laboratory cycling performance

2012 ◽  
Vol 37 (3) ◽  
pp. 425-436 ◽  
Author(s):  
David S. Rowlands ◽  
Marilla Swift ◽  
Marjolein Ros ◽  
Jackson G. Green
Keyword(s):  
High Intensity ◽  
Peak Power ◽  
Endurance Performance ◽  
Cycling Performance ◽  
Mountain Bike ◽  
Gastrointestinal Discomfort ◽  
Recorded Data ◽  
Intestinal Transporters ◽  
Maltodextrin Solution ◽  
Carbohydrate Solution

When ingested at high rates (1.8–2.4 g·min–1) in concentrated solutions, carbohydrates absorbed by multiple (e.g., fructose and glucose) vs. single intestinal transporters can increase exogenous carbohydrate oxidation and endurance performance, but their effect when ingested at lower, more realistic, rates during intermittent high-intensity endurance competition and trials is unknown. Trained cyclists participated in two independent randomized crossover investigations comprising mountain-bike races (average 141 min; n = 10) and laboratory trials (94-min high-intensity intervals followed by 10 maximal sprints; n = 16). Solutions ingested during exercise contained electrolytes and fructose + maltodextrin or glucose + maltodextrin in 1:2 ratio ingested, on average, at 1.2 g carbohydrate·kg–1·h–1. Exertion, muscle fatigue, and gastrointestinal discomfort were recorded. Data were analysed using mixed models with gastrointestinal discomfort as a mechanism covariate; inferences were made against substantiveness thresholds (1.2% for performance) and standardized difference. The fructose–maltodextrin solution substantially reduced race time (–1.8%; 90% confidence interval = ±1.8%) and abdominal cramps (–8.1 on a 0–100 scale; ±6.6). After accounting for gastrointestinal discomfort, the effect of the fructose–maltodextrin solution on lap time was reduced (–1.1%; ±2.4%), suggesting that gastrointestinal discomfort explained part of the effect of fructose–maltodextrin on performance. In the laboratory, mean sprint power was enhanced (1.4%; ±0.8%) with fructose–maltodextrin, but the effect on peak power was unclear (0.7%; ±1.5%). Adjusting out gastrointestinal discomfort augmented the fructose–maltodextrin effect on mean (2.6%; ±1.9%) and peak (2.5%; ±3.0%) power. Ingestion of multiple transportable vs. single transportable carbohydrates enhanced mountain-bike race and high-intensity laboratory cycling performance, with inconsistent but not irreconcilable effects of gut discomfort as a possible mediating mechanism.

Endurance Capacity and High-Intensity Exercise Performance Responses to a High-Fat Diet

2003 ◽  
Vol 13 (4) ◽  
pp. 466-478 ◽  
Author(s):  
Jesse Fleming ◽  
Matthew J. Sharman ◽  
Neva G. Avery ◽  
Dawn M. Love ◽  
Ana L. Gómez ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Body Mass ◽  
Exercise Performance ◽  
High Intensity ◽  
High Fat Diet ◽  
Peak Power ◽  
Perceived Exertion ◽  
Maximal Oxygen Consumption ◽  
Endurance Performance ◽  
High Fat

The effects of adaptation to a high-fat diet on endurance performance are equivocal, and there is little data regarding the effects on high-intensity exercise performance. This study examined the effects of a high-fat/moderate protein diet on submaximal, maximal, and supramaximal performance. Twenty non-highly trained men were assigned to either a high-fat/moderate-protein (HFMP; 61% fat) diet (n = 12) or a control (C; 25% fat) group (n = 8). A maximal oxygen consumption test, two 30-s Wingate anaerobic tests, and a 45-min timed ride were performed before and after 6 weeks of diet and training. Body mass decreased significantly (–2.2 kg; p ≤ .05) in HFMP subjects. Maximal oxygen consumption significantly decreased in the HFMP group (3.5 ± 0.14 to 3.27 ± 0.09 L · min−1) but was unaffected when corrected for body mass. Perceived exertion was significantly higher during this test in the HFMP group. Main time effects indicated that peak and mean power decreased significantly during bout 1 of the Wingate sprints in the HFMP (–10 and –20%, respectively) group but not the C (–8 and –16%, respectively) group. Only peak power was lower during bout 1 in the HFMP group when corrected for body mass. Despite significantly reduced RER values in the HFMP group during the 45-min cycling bout, work output was significantly decreased (–18%). Adaptation to a 6-week HFMP diet in non-highly trained men resulted in increased fat oxidation during exercise and small decrements in peak power output and endurance performance. These deleterious effects on exercise performance may be accounted for in part by a reduction in body mass and/or increased ratings of perceived exertion.

Solid, Gel, and Liquid Carbohydrate Format Effects on Gut Comfort and Performance

2017 ◽  
Vol 27 (3) ◽  
pp. 247-254 ◽  
Author(s):  
Mathilde Guillochon ◽  
David S. Rowlands
Keyword(s):  
Peak Power ◽  
Perceived Exertion ◽  
Endurance Performance ◽  
Cycling Performance ◽  
Performance Outcomes ◽  
Double Blind ◽  
Fluid Ingestion ◽  
Comparable Performance ◽  
And Performance ◽  
Format Effects

Carbohydrate sports drinks produce worthwhile benefits to endurance performance compared with noncaloric controls. However, athletes now consume carbohydrate in a range of formats, including gels and bars, but the comparable performance outcomes are unknown. Therefore, the aim of this study was to establish the relative effects of drink, gel, bar, and mixed carbohydrate formats on intense cycling performance. In a treatmentapparent randomized crossover design, 12 well-trained male cyclists completed 4 trials comprising a 140-min race simulation, followed by a double-blind slow-ramp to exhaustion (0.333 W·s-1). Carbohydrate comprising fructose and maltodextrin was ingested every 20 min via commercial drink, gel, bar, or mix of all 3, providing 80 g carbohydrate·h-1. Fluid ingestion was 705 ml·h-1. Exertion, fatigue, and gastrointestinal discomfort were measured with VAS. Performance peak power (SD) was 370 (41), 376 (37), 362 (51) and 368 W (54) for drink, gels, bars, and mix respectively. The reduction in power (-3.9%; 90%CI ±4.3) following bar ingestion vs. gel was likely substantial (likelihood harm 81.2%; benefit 0.8%), but no clear differences between drinks, gels, and the mix were evident. Bars also produced small-moderate standardized increases in nausea, stomach fullness, abdominal cramps, and perceived exertion, relative to gels (likelihood harm 95–99.5%; benefit <0.01%) and drink (75–95%; <0.01%); mix also increased nausea relative to gels (95%; <0.01%). Relative to a gel, carbohydrate bar ingestion reduced peak power, gut comfort, and ease of exertion; furthermore, no clear difference relative to drink suggests bars alone are the less favorable exogenous-carbohydrate energy source for intense endurance performance.

Cycling Performance Following Adaptation to Two Protocols of Acutely Intermittent Hypoxia

2009 ◽  
Vol 4 (1) ◽  
pp. 68-83 ◽  
Author(s):  
Darrell L. Bonetti ◽  
Will G. Hopkins ◽  
Timothy E. Lowe ◽  
Andrew E. Kilding
Keyword(s):  
Intermittent Hypoxia ◽  
Peak Power ◽  
Venous Blood ◽  
Endurance Performance ◽  
Cycling Performance ◽  
Hypoxic Exposure ◽  
Control Group ◽  
Post Intervention ◽  
Repeated Sprint ◽  
Competitive Cyclists

Purpose:Adaptation to acutely intermittent hypoxic exposure appears to produce worthwhile enhancements in endurance performance, but the current 5-min duration of hypoxia and recovery intervals may not be optimal.Methods:Eighteen male competitive cyclists and triathletes were randomized to one of two intermittent-hypoxia groups, and nine similar athletes represented a control group. Athletes in the hypoxia groups were exposed to 60 min per day of intermittent hypoxia consisting of alternating intervals of hypoxia and normoxia lasting either 3 or 5 min. Exposures were performed at rest for 5 consecutive days per week for 3 wk. Oxygen saturation, monitored with pulse oximetry, was reduced progressively from 90% (day 1) to 76% (day 15). All athletes maintained their usual competitive-season training throughout the study. Incremental and repeated-sprint tests were performed pre, 3 d post, and 14 d post intervention. Venous blood at rest was sampled pre, mid-, and postintervention.Results:There were no clear differences between effects of the two hypoxic treatments on performance or various measures of oxygen transport, hematopoiesis, and inflammation. Compared with control, the combined hypoxic groups showed clear enhancements in peak power (4.7%; 90% confidence limits, ±3.1%), lactate-profile power (4.4%; ±3.0%), and heart-rate profle power (6.5%; ±5.3%) at 3 d post intervention, but at 14 d the effects were unclear. Changes in other measures at 3 and 14 d post intervention were either unclear or unremarkable.Conclusion:Acutely intermittent hypoxia produced substantial enhancement in endurance performance, but the relative benefit of 3- vs 5-min exposure intervals remains unclear.

An Investigation into the Effects of Sodium Citrate Ingestion on High-Intensity Exercise Performance

1998 ◽  
Vol 8 (4) ◽  
pp. 356-363 ◽  
Author(s):  
Ken van Someren ◽  
Kathy Fulcher ◽  
John McCarthy ◽  
Jonathan Moore ◽  
Gill Horgan ◽  
...  
Keyword(s):  
Blood Lactate ◽  
Exercise Performance ◽  
High Intensity ◽  
Peak Power ◽  
Sodium Citrate ◽  
Intermittent Exercise ◽  
Cycling Performance ◽  
Total Work ◽  
Citrate Solution ◽  
Blood Ph

This study examined the effect of sodium citrate ingestion on high-intensity cycling performance in repeated 45-s bouts. Twelve subjects (9 male and 3 female) ingested either a sodium citrate solution (0.3 g ⋅ kg−1 body mass [BM]) or a placebo 90 min prior to exercise. Postingestion blood HCO3 concentrations were significantly higher in the citrate trial (p < .01), but there was no difference in blood pH between trials. Peak power and total work significantly decreased over the five bouts (p < .05) and postexercise blood lactate concentrations significantly increased over the five bouts (p < 0.01), but there were no differences between trials. We conclude that sodium citrate ingestion (0.3 g ⋅ kg−1 BM) is not an effective ergogenic aid for high-intensity, intermittent exercise as simulated in this protocol.

Moderate- and High-Intensity Inspiratory Muscle Training Equally Improves Inspiratory Muscle Strength and Endurance—A Double-Blind Randomized Controlled Trial

2020 ◽  
pp. 1-9
Author(s):  
Patricia Rehder-Santos ◽  
Raphael M. Abreu ◽  
Étore De F. Signini ◽  
Claudio D. da Silva ◽  
Camila A. Sakaguchi ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Oxygen Uptake ◽  
High Intensity ◽  
Peak Power ◽  
Sham Group ◽  
Inspiratory Muscle ◽  
Inspiratory Pressure ◽  
Moderate Intensity ◽  
Muscle Training ◽  
Inspiratory Muscle Strength

Background and Objective: Inspiratory muscle training (IMT) produced outstanding results in the physical performance of active subjects; however, little is known about the best training intensity for this population. The objective was to investigate the impact of an IMT of high intensity, using the critical inspiratory pressure (CIP), on inspiratory muscle strength (IMS), inspiratory muscle endurance (IME), peak power, and oxygen uptake of recreational cyclists; and to compare these results with moderate-intensity IMT (60% of maximal inspiratory pressure [MIP]). Methods: Thirty apparently healthy male recreational cyclists, 20–40 years old, underwent 11 weeks of IMT (3 times per week; 55 min per session). Participants were randomized into 3 groups: sham group (6 cmH2O; n = 8); 60% MIP (MIP60; n = 10) and CIP (n = 12). All participants performed the IMS test and incremental IME test at the first, fifth, ninth, and 13th weeks of the experimental protocol. Cardiopulmonary exercise testing was performed on an electromagnetic braking cycle ergometer pre-IMT and post-IMT. Data were analyzed using a 2-way repeated measures ANOVA (group and period factors). Results: IMS increased in CIP and MIP60 groups at the ninth and 13th weeks compared with the sham group (P < .001; β = 0.99). Regarding IME, there was an interaction between the CIP and MIP60 groups in all periods, except in the initial evaluation (P < .001; β = 1.00). Peak power (in watts) increased after IMT in CIP and MIP60 groups (P = .01; β = 0.67). Absolute oxygen uptake did not increase after IMT (P = .49; β = 0.05). Relative oxygen uptake to lean mass values did not change significantly (P = .48; β = 0.05). Conclusion: High-intensity IMT is beneficial on IMS, IME, and peak power, but does not provide additional gain to moderate intensity in recreational cyclists.

Six weeks of a polarized training-intensity distribution leads to greater physiological and performance adaptations than a threshold model in trained cyclists

2013 ◽  
Vol 114 (4) ◽  
pp. 461-471 ◽  
Author(s):  
Craig M. Neal ◽  
Angus M. Hunter ◽  
Lorraine Brennan ◽  
Aifric O'Sullivan ◽  
D. Lee Hamilton ◽  
...  
Keyword(s):  
Exercise Capacity ◽  
Intensity Distribution ◽  
High Intensity ◽  
Threshold Model ◽  
Endurance Performance ◽  
High Intensity Exercise ◽  
Metabolic Adaptation ◽  
Mitochondrial Enzyme ◽  
Training Intensity ◽  
Metabolomics Analysis

This study was undertaken to investigate physiological adaptation with two endurance-training periods differing in intensity distribution. In a randomized crossover fashion, separated by 4 wk of detraining, 12 male cyclists completed two 6-wk training periods: 1) a polarized model [6.4 (±1.4 SD) h/wk; 80%, 0%, and 20% of training time in low-, moderate-, and high-intensity zones, respectively]; and 2) a threshold model [7.5 (±2.0 SD) h/wk; 57%, 43%, and 0% training-intensity distribution]. Before and after each training period, following 2 days of diet and exercise control, fasted skeletal muscle biopsies were obtained for mitochondrial enzyme activity and monocarboxylate transporter (MCT) 1 and 4 expression, and morning first-void urine samples were collected for NMR spectroscopy-based metabolomics analysis. Endurance performance (40-km time trial), incremental exercise, peak power output (PPO), and high-intensity exercise capacity (95% maximal work rate to exhaustion) were also assessed. Endurance performance, PPOs, lactate threshold (LT), MCT4, and high-intensity exercise capacity all increased over both training periods. Improvements were greater following polarized rather than threshold for PPO [mean (±SE) change of 8 (±2)% vs. 3 (±1)%, P < 0.05], LT [9 (±3)% vs. 2 (±4)%, P < 0.05], and high-intensity exercise capacity [85 (±14)% vs. 37 (±14)%, P < 0.05]. No changes in mitochondrial enzyme activities or MCT1 were observed following training. A significant multilevel, partial least squares-discriminant analysis model was obtained for the threshold model but not the polarized model in the metabolomics analysis. A polarized training distribution results in greater systemic adaptation over 6 wk in already well-trained cyclists. Markers of muscle metabolic adaptation are largely unchanged, but metabolomics markers suggest different cellular metabolic stress that requires further investigation.

The Effects of Compression Garments on Intermittent Exercise Performance and Recovery on Consecutive Days

2008 ◽  
Vol 3 (4) ◽  
pp. 454-468 ◽  
Author(s):  
Rob Duffield ◽  
Johann Edge ◽  
Robert Merrells ◽  
Emma Hawke ◽  
Matt Barnes ◽  
...  
Keyword(s):  
Heart Rate ◽  
Exercise Performance ◽  
High Intensity ◽  
Peak Power ◽  
Muscle Soreness ◽  
Sport Activity ◽  
Team Sport ◽  
Tympanic Temperature ◽  
Exercise Protocol ◽  
Compression Garments

Purpose:The aim of this study was to determine whether compression garments improve intermittent-sprint performance and aid performance or self-reported recovery from high-intensity efforts on consecutive days.Methods:Following familiarization, 14 male rugby players performed two randomized testing conditions (with or without garments) involving consecutive days of a simulated team sport exercise protocol, separated by 24 h of recovery within each condition and 2 weeks between conditions. Each day involved an 80-min high-intensity exercise circuit, with exercise performance determined by repeated 20-m sprints and peak power on a cart dynamometer (single-man scrum machine). Measures of nude mass, heart rate, skin and tympanic temperature, and blood lactate (La−) were recorded throughout each day; also, creatine kinase (CK) and muscle soreness were recorded each day and 48 h following exercise.Results:No differences (P = .20 to 0.40) were present between conditions on either day of the exercise protocol for repeated 20-m sprint efforts or peak power on a cart dynamometer. Heart rate, tympanic temperature, and body mass did not significantly differ between conditions; however, skin temperature was higher under the compression garments. Although no differences (P = .50) in La− or CK were present, participants felt reduced levels of perceived muscle soreness in the ensuing 48 h postexercise when wearing the garments (2.5 ± 1.7 vs 3.5 ± 2.1 for garment and control; P = .01).Conclusions:The use of compression garments did not improve or hamper simulated team-sport activity on consecutive days. Despite benefits of reduced self-reported muscle soreness when wearing garments during and following exercise each day, no improvements in performance or recovery were apparent.

Dietary Antioxidant Supplementation Combined with Quercetin Improves Cycling Time Trial Performance

2006 ◽  
Vol 16 (4) ◽  
pp. 405-419 ◽  
Author(s):  
Holden S-H. MacRae ◽  
Kari M. Mefferd
Keyword(s):  
Peak Power ◽  
Time Trial ◽  
Cycling Performance ◽  
Antioxidant Supplementation ◽  
Double Blind ◽  
Cycling Time Trial ◽  
Dietary Antioxidant ◽  
Power Peak ◽  
Manova Analysis ◽  
Trial Performance

We investigated whether 6 wk of antioxidant supplementation (AS) would enhance 30 km time trial (TT) cycling performance. Eleven elite male cyclists completed a randomized, double-blind, cross-over study to test the effects of twice daily AS containing essential vitamins plus quercetin (FRS), and AS minus quercetin (FRS-Q) versus a baseline TT (B). MANOVA analysis showed that time to complete the 30 km TT was improved by 3.1% on FRS compared to B (P ≤ 0.01), and by 2% over the last 5 km (P ≤ 0.05). Absolute and relative (%HRmax) heart rates and percent VO2max were not different between trials, but average and relative power (% peak power) was higher on FRS (P ≤ 0.01). Rates of carbohydrate and fat oxidation were not different between trials. Thus, FRS supplementation significantly improved high-intensity cycling TT performance through enhancement of power output. Further study is needed to determine the potential mechanism(s) of the antioxidant efficacy.

The Acute Effects of Citrulline-Malate Supplementation on High Intensity Cycling Performance and Muscle Oxygenation

2014 ◽  
Vol 46 ◽  
pp. 132
Author(s):  
Brian Cunniffe ◽  
Maria Papageorge ◽  
Barbara O’Brien ◽  
George K. Grimble ◽  
Nathan A. Davies ◽  
...  
Keyword(s):  
High Intensity ◽  
Cycling Performance ◽  
Muscle Oxygenation ◽  
Acute Effects ◽  
Citrulline Malate

scholarly journals Effects of a 2-km Swim on Markers of Cycling Performance in Elite Age-Group Triathletes

Sports ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 82
Author(s):  
Jeffrey Rothschild ◽  
George H. Crocker
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Blood Lactate ◽  
Peak Power ◽  
Maximal Oxygen Consumption ◽  
Lactate Concentration ◽  
Blood Lactate Concentration ◽  
Cycling Performance ◽  
Age Group

The purpose of this study was to examine the effects of a 2-km swim on markers of subsequent cycling performance in well-trained, age-group triathletes. Fifteen participants (10 males, five females, 38.3 ± 8.4 years) performed two progressive cycling tests between two and ten days apart, one of which was immediately following a 2-km swim (33.7 ± 4.1 min). Cycling power at 4-mM blood lactate concentration decreased after swimming by an average of 3.8% (p = 0.03, 95% CI −7.7, 0.2%), while heart rate during submaximal cycling (220 W for males, 150 W for females) increased by an average of 4.0% (p = 0.02, 95% CI 1.7, 9.7%), compared to cycling without prior swimming. Maximal oxygen consumption decreased by an average of 4.0% (p = 0.01, 95% CI −6.5, −1.4%), and peak power decreased by an average of 4.5% (p < 0.01, 95% CI −7.3, −2.3%) after swimming, compared to cycling without prior swimming. Results from this study suggest that markers of submaximal and maximal cycling are impaired following a 2-km swim.

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