Effects of creatine loading and prolonged creatine supplementation on body composition, fuel selection, sprint and endurance performance in humans

2003 ◽  
Vol 104 (2) ◽  
pp. 153-162 ◽  
Author(s):  
Luc J.C. van LOON ◽  
Audrey M. OOSTERLAAR ◽  
Fred HARTGENS ◽  
Matthijs K.C. HESSELINK ◽  
Rodney J. SNOW ◽  
...  
Keyword(s):  
Body Composition ◽  
Creatine Supplementation ◽  
Time Trial ◽  
Oxidative Capacity ◽  
Substrate Utilization ◽  
Cycle Ergometer ◽  
Fat Free Mass ◽  
Whole Body ◽  
Total Creatine ◽  
Trial Performance

Most research on creatine has focused on short-term creatine loading and its effect on high-intensity performance capacity. Some studies have investigated the effect of prolonged creatine use during strength training. However, studies on the effects of prolonged creatine supplementation are lacking. In the present study, we have assessed the effects of both creatine loading and prolonged supplementation on muscle creatine content, body composition, muscle and whole-body oxidative capacity, substrate utilization during submaximal exercise, and on repeated supramaximal sprint, as well as endurance-type time-trial performance on a cycle ergometer. Twenty subjects ingested creatine or a placebo during a 5-day loading period (20g·day-1) after which supplementation was continued for up to 6 weeks (2g·day-1). Creatine loading increased muscle free creatine, creatine phosphate (CrP) and total creatine content (P<0.05). The subsequent use of a 2g·day-1 maintenance dose, as suggested by an American College of Sports Medicine Roundtable, resulted in a decline in both the elevated CrP and total creatine content and maintenance of the free creatine concentration. Both short- and long-term creatine supplementation improved performance during repeated supramaximal sprints on a cycle ergometer. However, whole-body and muscle oxidative capacity, substrate utilization and time-trial performance were not affected. The increase in body mass following creatine loading was maintained after 6 weeks of continued supplementation and accounted for by a corresponding increase in fat-free mass. This study provides definite evidence that prolonged creatine supplementation in humans does not increase muscle or whole-body oxidative capacity and, as such, does not influence substrate utilization or performance during endurance cycling exercise. In addition, our findings suggest that prolonged creatine ingestion induces an increase in fat-free mass.

scholarly journals Effects of supplementing with an 18% carbohydrate-hydrogel drink versus a placebo during whole-body exercise in −5 °C with elite cross-country ski athletes: a crossover study

2019 ◽  
Vol 16 (1) ◽  
Author(s):  
Stefan Pettersson ◽  
Fredrik Edin ◽  
Linda Bakkman ◽  
Kerry McGawley
Keyword(s):  
Gastrointestinal Symptoms ◽  
Time Trial ◽  
Substrate Utilization ◽  
Carbohydrate Oxidation ◽  
Whole Body ◽  
Double Poling ◽  
Cross Country Skiing ◽  
Cross Country ◽  
Carbohydrate Solution ◽  
Trial Performance

Abstract Background Whilst the ergogenic effects of carbohydrate intake during prolonged exercise are well-documented, few investigations have studied the effects of carbohydrate ingestion during cross-country skiing, a mode of exercise that presents unique metabolic demands on athletes due to the combined use of large upper- and lower-body muscle masses. Moreover, no previous studies have investigated exogenous carbohydrate oxidation rates during cross-country skiing. The current study investigated the effects of a 13C-enriched 18% multiple-transportable carbohydrate solution (1:0.8 maltodextrin:fructose) with additional gelling polysaccharides (CHO-HG) on substrate utilization and gastrointestinal symptoms during prolonged cross-country skiing exercise in the cold, and subsequent double-poling time-trial performance in ~ 20 °C. Methods Twelve elite cross-country ski athletes (6 females, 6 males) performed 120-min of submaximal roller-skiing (69.3 ± 2.9% of $$ \dot{\mathrm{V}} $$V̇O2peak) in −5 °C while receiving either 2.2 g CHO-HG·min− 1 or a non-caloric placebo administered in a double-blind, randomized manner. Whole-body substrate utilization and exogenous carbohydrate oxidation was calculated for the last 60 min of the submaximal exercise. The maximal time-trial (2000 m for females, 2400 m for males) immediately followed the 120-min submaximal bout. Repeated-measures ANOVAs with univariate follow-ups were conducted, as well as independent and paired t-tests, and significance was set at P < 0.05. Data are presented as mean ± SD. Results Exogenous carbohydrate oxidation contributed 27.6 ± 6.6% to the total energy yield with CHO-HG and the peak exogenous carbohydrate oxidation rate reached 1.33 ± 0.27 g·min− 1. Compared to placebo, fat oxidation decreased by 9.5 ± 4.8% with CHO-HG, total carbohydrate oxidation increased by 9.5 ± 4.8% and endogenous carbohydrate utilization decreased by 18.1 ± 6.4% (all P < 0.05). No severe gastrointestinal symptoms were reported in either trial and euhydration was maintained in both trials. Time-trial performance (8.4 ± 0.4 min) was not improved following CHO-HG compared to placebo (− 0.8 ± 3.5 s; 95% confidence interval − 3.0 to 1.5 s; P = 0.46). No sex differences were identified in substrate utilization or relative performance. Conclusions Ingestion of an 18% multiple-transportable carbohydrate solution with gelling polysaccharides was found to be well-tolerated during 120 min of submaximal whole-body exercise, but did not improve subsequent maximal double-poling performance.

Beneficial Effects of Ice Ingestion as a Precooling Strategy on 40-km Cycling Time-Trial Performance

2010 ◽  
Vol 5 (2) ◽  
pp. 140-151 ◽  
Author(s):  
Mohammed Ihsan ◽  
Grant Landers ◽  
Matthew Brearley ◽  
Peter Peeling
Keyword(s):  
Perceived Exertion ◽  
Thermal Sensation ◽  
Tap Water ◽  
Time Trial ◽  
Cycle Ergometer ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Crushed Ice ◽  
Cycling Time ◽  
Trial Performance

Purpose:The effect of crushed ice ingestion as a precooling method on 40-km cycling time trial (CTT) performance was investigated.Methods:Seven trained male subjects underwent a familiarization trial and two experimental CTT which were preceded by 30 min of either crushed ice ingestion (ICE) or tap water (CON) consumption amounting to 6.8 g⋅kg-1 body mass. The CTT required athletes to complete 1200 kJ of work on a wind-braked cycle ergometer. During the CTT, gastrointestinal (Tgi) and skin (Tsk) temperatures, cycling time, power output, heart rate (HR), blood lactate (BLa), ratings of perceived exertion (RPE) and thermal sensation (RPTS) were measured at set intervals of work.Results:Precooling lowered the Tgi after ICE significantly more than CON (36.74 ± 0.67°C vs 37.27 ± 0.24°C, P < .05). This difference remained evident until 200 kJ of work was completed on the bike (37.43 ± 0.42°C vs 37.64 ± 0.21°C). No significant differences existed between conditions at any time point for Tsk, RPE or HR (P > .05). The CTT completion time was 6.5% faster in ICE when compared with CON (ICE: 5011 ± 810 s, CON: 5359 ± 820 s, P < .05).Conclusions:Crushed ice ingestion was effective in lowering Tgi and improving subsequent 40-km cycling time trial performance. The mechanisms for this enhanced exercise performance remain to be clarified.

Effects of acute creatine monohydrate supplementation on leucine kinetics and mixed-muscle protein synthesis

2001 ◽  
Vol 91 (3) ◽  
pp. 1041-1047 ◽  
Author(s):  
G. Parise ◽  
S. Mihic ◽  
D. MacLennan ◽  
K. E. Yarasheski ◽  
M. A. Tarnopolsky
Keyword(s):  
Protein Synthesis ◽  
Muscle Protein ◽  
Muscle Protein Synthesis ◽  
Fat Free Mass ◽  
Whole Body ◽  
Synthetic Rate ◽  
Fractional Synthetic Rate ◽  
Before And After ◽  
Total Creatine ◽  
Plasma Leucine

Creatine monohydrate (CrM) supplementation during resistance exercise training results in a greater increase in strength and fat-free mass than placebo. Whether this is solely due to an increase in intracellular water or whether there may be alterations in protein turnover is not clear at this point. We examined the effects of CrM supplementation on indexes of protein metabolism in young healthy men ( n = 13) and women ( n = 14). Subjects were randomly allocated to CrM (20 g/day for 5 days followed by 5 g/day for 3–4 days) or placebo (glucose polymers) and tested before and after the supplementation period under rigorous dietary and exercise controls. Muscle phosphocreatine, creatine, and total creatine were measured before and after supplementation. A primed-continuous intravenous infusion of l-[1-13C]leucine and mass spectrometry were used to measure mixed-muscle protein fractional synthetic rate and indexes of whole body leucine metabolism (nonoxidative leucine disposal), leucine oxidation, and plasma leucine rate of appearance. CrM supplementation increased muscle total creatine (+13.1%, P < 0.05) with a trend toward an increase in phosphocreatine (+8.8%, P = 0.09). CrM supplementation did not increase muscle fractional synthetic rate but reduced leucine oxidation (−19.6%) and plasma leucine rate of appearance (−7.5%, P < 0.05) in men, but not in women. CrM did not increase total body mass or fat-free mass. We conclude that short-term CrM supplementation may have anticatabolic actions in some proteins (in men), but CrM does not increase whole body or mixed-muscle protein synthesis.

scholarly journals Serum levels of 25 (OH) vitamin D in adults with obesity sarcopenia

2020 ◽  
Vol 79 (OCE2) ◽  
Author(s):  
Maria Nikolova ◽  
Alexander Penkov
Keyword(s):  
Vitamin D ◽  
Body Composition ◽  
Fat Mass ◽  
Lean Mass ◽  
Fat Free Mass ◽  
Whole Body ◽  
Composition Analysis ◽  
Appendicular Lean Mass ◽  
Vitamin D Levels ◽  
25 Oh Vitamin D

AbstractIntroduction:Obesity has been linked with vitamin D deficiency in a number of cross-sectional studies, reviews and meta-analyses. To assess the correlations of plasma 25(OH) vitamin D levels with indices of body composition examined by DXA with an emphasis on lean and bone mass as well as on indices such as android/gynoid fat, appendicular lean mass (ALM) and appendicular lean mass index (ALMI), fat-mass indexes (FMI), fat-free mass indexes (FFMI) and the ALM-to-BMI index.Materials and Methods:62 adult subjects consented to participate – 27 men (43.5 %) and 35 women (56.5 %). Their mean age was 45.3 ± 9.5 years. Fan-beam dual-energy X-ray (DXA) body composition analysis was performed on a Lunar Prodigy Pro bone densitometer with software version 12.30. Vitamin D was measured by electro-hemi-luminescent detection as 25(OH)D Total (ECLIA, Elecsys 2010 analyzer, Roche Diagnostics). Statistical analyses were done using the SPSS 23.0 statistical package.Results:The serum 25(OH)D level was correlated significantly only to the whole body bone mineral content, the appendicular lean mass index (ALMI) and the ALM-to-BMI index, underlining a predominant role for lean and fat-free mass. Vitamin D showed a very weak correlation to % Body Fat and the Fat Mass Index (FMI) in men only. Moreover, the multiple regression equation including the associated parameters could explain only 7 % of the variation in the serum 25(OH)D levels.Discussion:Our conclusion was, that there are differences in the associations of the vitamin D levels with the different body composition indices, but these associations are generally very weak and therefore – negligible.

Effect of Repeated Sodium Phosphate Loading on Cycling Time-Trial Performance and VO2peak

2013 ◽  
Vol 23 (2) ◽  
pp. 187-194 ◽  
Author(s):  
Cameron P. Brewer ◽  
Brian Dawson ◽  
Karen E. Wallman ◽  
Kym J. Guelfi
Keyword(s):  
Sodium Phosphate ◽  
Time Trial ◽  
Peak Oxygen Uptake ◽  
Fat Free Mass ◽  
Mean Power ◽  
Time Trial Performance ◽  
Cycling Time Trial ◽  
Placebo Phase ◽  
Cycling Time ◽  
Trial Performance

Research into supplementation with sodium phosphate has not investigated the effects of a repeated supplementation phase. Therefore, this study examined the potential additive effects of repeated sodium phosphate (SP) supplementation on cycling time-trial performance and peak oxygen uptake (VO2peak). Trained male cyclists (N = 9, M ± SD VO2peak = 65.2 ± 4.8 ml · kg−1 · min−1) completed baseline 1,000-kJ time-trial and VO2peak tests separated by 48 hr, then ingested either 50 mg · kg fat-free mass−1 · d−1 of tribasic SP or a combined glucose and NaCl placebo for 6 d before performing these tests again. A 14-d washout period separated the end of one loading phase and the start of the next, with 2 SP and 1 placebo phase completed in a counterbalanced order. Although time-trial performance (55.3–56.5 min) was shorter in SP1 and SP2 (~60–70 s), effect sizes and smallest-worthwhile-change values did not differ in comparison with baseline and placebo. However, mean power output was greater than placebo during time-trial performance at the 250-kJ and 500-kJ time points (p < .05) after the second SP phase. Furthermore, mean VO2peak values (p < .01) were greater after the SP1 (3.5–4.3%), with further improvements (p < .01) found in SP2 (7.1–7.7%), compared with baseline and placebo. In summary, repeated SP supplementation, ingested either 15 or 35 d after initial loading, can have an additive effect on VO2peak and possibly time-trial performance.

Muscularity and the density of the fat-free mass in athletes

2001 ◽  
Vol 90 (4) ◽  
pp. 1523-1531 ◽  
Author(s):  
Barry M. Prior ◽  
Christopher M. Modlesky ◽  
Ellen M. Evans ◽  
Mark A. Sloniger ◽  
Michael J. Saunders ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Body Composition ◽  
Collegiate Athletes ◽  
Fat Free Mass ◽  
Component Model ◽  
Whole Body ◽  
Entire Group ◽  
Body Density ◽  
Musculoskeletal Development ◽  
Four Component Model

The purpose of this study was to use estimates of body composition from a four-component model to determine whether the density of the fat-free mass (DFFM) is affected by muscularity or musculoskeletal development in a heterogenous group of athletes and nonathletes. Measures of body density by hydrostatic weighing, body water by deuterium dilution, bone mineral by whole body dual-energy X-ray absorptiometry (DXA), total body skeletal muscle estimated from DXA, and musculoskeletal development as measured by the mesomorphy rating from the Heath-Carter anthropometric somatotype were obtained in 111 collegiate athletes (67 men and 44 women) and 61 nonathletes (24 men and 37 women). In the entire group, DFFM varied from 1.075 to 1.127 g/cm3 and was strongly related to the water and protein fractions of the fat-free mass (FFM; r = −0.96 and 0.89) and moderately related to the mineral fraction of the FFM ( r = 0.65). Skeletal muscle (%FFM) varied from 40 to 68%, and mesomorphy varied from 1.6 to 9.6, but neither was significantly related to DFFM( r = 0.11 and −0.14) or to the difference between percent fat estimated from the four-component model and from densitometry ( r = 0.09 and −0.16). We conclude that, in a heterogeneous group of young adult athletes and nonathletes, DFFM and the accuracy of estimates of body composition from body density using the Siri equation are not related to muscularity or musculoskeletal development. Athletes in selected sports may have systematic deviations in DFFM from the value of 1.1 g/cm3 assumed in the Siri equation, resulting in group mean errors in estimation of percent fat from densitometry of 2–5% body mass, but the cause of these deviations is complex and not simply a reflection of differences in muscularity or musculoskeletal development.

Whole Body Fat Free Mass and Vo2peak in Recreationally Active Men and Women

2020 ◽  
Vol 91 (2) ◽  
pp. 102-105
Author(s):  
Charles Paul Lambert
Keyword(s):  
Muscle Mass ◽  
Body Fat ◽  
Cycle Ergometer ◽  
Fat Free Mass ◽  
Whole Body ◽  
Men And Women ◽  
Primary Driver ◽  
Hydrostatic Weighing ◽  
Verification Test ◽  
Oxygen Difference

BACKGROUND: Vo2peak has traditionally been thought to be regulated by cardiac output and arteriovenous-oxygen difference. A “muscle-centric” view suggests the cardiovascular system is secondarily responsive to the primary driver: active muscle mass.METHODS: A total of 19 recreationally active men (N = 10) and women (N = 9) performed a Vo2peak test, a Vo2peak verification test on an electrically braked cycle ergometer on the same day, and a hydrostatic weighing test to assess fat free mass after providing written informed consent.RESULTS: Vo2peak was significantly higher in men (3.74 ± 0.6 L · min−1) than women (2.22 ± 0.30 L · min−1). Whole body fat free mass explained 91% of the variability in Vo2peak (R2 = 0.91) in the men and women combined, 81% of the variability in Vo2peak in men alone, and 46% of the variability in Vo2peak in women alone. None of these subjects were highly trained.DISCUSSION: Fat free mass, a surrogate for muscle mass, was the primary predictor of Vo2peak in this group of recreationally active men and women. Therefore, it appears that whole body fat free mass (a surrogate for muscle mass) is the primary driver for Vo2peak in these recreationally active men and women. These data have implications as to the type of training NASA personnel should be undertaking: resistance training as opposed to aerobic training.Lambert CP. Whole body fat free mass and Vo2peak in recreationally active men and women. Aerosp Med Hum Perform. 2020; 91(2):102–105.

Creatine supplementation increases muscle total creatine but not maximal intermittent exercise performance

1999 ◽  
Vol 87 (6) ◽  
pp. 2244-2252 ◽  
Author(s):  
Michael J. McKenna ◽  
Judith Morton ◽  
Steve E. Selig ◽  
Rodney J. Snow
Keyword(s):  
Time Course ◽  
Intermittent Exercise ◽  
Vastus Lateralis ◽  
Creatine Supplementation ◽  
Creatine Phosphate ◽  
Dry Mass ◽  
Cycle Ergometer ◽  
Initial Increase ◽  
Main Effect ◽  
Total Creatine

This study investigated creatine supplementation (CrS) effects on muscle total creatine (TCr), creatine phosphate (CrP), and intermittent sprinting performance by using a design incorporating the time course of the initial increase and subsequent washout period of muscle TCr. Two groups of seven volunteers ingested either creatine [Cr; 6 × (5 g Cr-H2O + 5 g dextrose)/day)] or a placebo (6 × 5 g dextrose/day) over 5 days. Five 10-s maximal cycle ergometer sprints with rest intervals of 180, 50, 20, and 20 s and a resting vastus lateralis biopsy were conducted before and 0, 2, and 4 wk after placebo or CrS. Resting muscle TCr, CrP, and Cr were unchanged after the placebo but were increased ( P < 0.05) at 0 [by 22.9 ± 4.2, 8.9 ± 1.9, and 14.0 ± 3.3 (SE) mmol/kg dry mass, respectively] and 2 but not 4 wk after CrS. An apparent placebo main effect of increased peak power and cumulative work was found after placebo and CrS, but no treatment (CrS) main effect was found on either variable. Thus, despite the rise and washout of muscle TCr and CrP, maximal intermittent sprinting performance was unchanged by CrS.

Dietary Composition Influences Short-term Endurance Training–Induced Adaptations of Substrate Partitioning during Exercise

2004 ◽  
Vol 14 (1) ◽  
pp. 38-61 ◽  
Author(s):  
Kevin A. Jacobs ◽  
David R. Paul ◽  
Ray J. Geor ◽  
Kenneth W. Hinchcliff ◽  
W. Michael Sherman
Keyword(s):  
Endurance Training ◽  
Time Trial ◽  
Whole Body ◽  
High Fat ◽  
Short Term ◽  
Time Trial Performance ◽  
Glucose Flux ◽  
Before And After ◽  
Substrate Partitioning ◽  
Trial Performance

The purpose of the current study was to examine the influence of dietary composition on short-term endurance training–induced adaptations of substrate partitioning and time trial exercise performance. Eight untrained males cycled for 90 min at ~54% aerobic capacity while being infused with [6,62H]glucose before and after two 10-d experimental phases separated by a 2-week washout period. Time trial performance was measured after the 90-min exercise trials before and after the 2nd experimental phase. During the first 10-d phase, subjects were randomly assigned to consume either a high carbohydrate or high fat diet while remaining inactive (CHO or FAT). During the second 10-d phase, subjects consumed the opposite diet, and both groups performed identical daily supervised endurance training (CHO+T or FAT+T). CHO and CHO+T did not affect exercise metabolism. FAT reduced glucose flux at the end of exercise, while FAT+T substantially increased whole body lipid oxidation during exercise and reduced glucose flux at the end of exercise. Despite these differences in adaptation of substrate use, training resulted in similar improvements in time trial performance for both groups. We conclude that (a) 10-d high fat diets result in substantial increases in whole body lipid oxidation during exercise when combined with daily aerobic training, and (b) diet does not affect short-term training-induced improvements in high-intensity time trial performance.

scholarly journals Techniques for the study of energy balance in man

2003 ◽  
Vol 62 (2) ◽  
pp. 529-537 ◽  
Author(s):  
Marinos Elia ◽  
Rebecca Stratton ◽  
James Stubbs
Keyword(s):  
Body Composition ◽  
Measurement Error ◽  
Energy Balance ◽  
Energy Intake ◽  
Dual Energy ◽  
The Body ◽  
Fat Free Mass ◽  
Whole Body ◽  
X Ray ◽  
Body Segments

Energy balance can be estimated in tissues, body segments, individual subjects (the focus of the present article), groups of subjects and even societies. Changes in body composition in individual subjects can be translated into changes in the energy content of the body, but this method is limited by the precision of the techniques. The precision for measuring fat and fat-free mass can be as low as 0.5 kg when certain reference techniques are used (hydrodensitometry, air-displacement plethysmography, dual-energy X-ray absorptiometry), and approximately 0.7 kg for changes between two time points. Techniques associated with a measurement error of 0.7 kg for changes in fat and fat-free mass (approximately 18MJ) are of little or no value for calculating energy balance over short periods of time, but they may be of some value over long periods of time (18 MJ over 1 year corresponds to an average daily energy balance of 70 kJ, which is <1% of the normal dietary energy intake). Body composition measurements can also be useful in calculating changes in energy balance when the changes in body weight and composition are large, e.g. >5–10 kg. The same principles can be applied to the assessment of energy balance in body segments using dual-energy X-ray absorptiometry. Energy balance can be obtained over periods as short as a few minutes, e.g. during measurements of BMR. The variability in BMR between individuals of similar age, weight and height and gender is about 7–9%, most of which is of biological origin rather than measurement error, which is about 2%. Measurement of total energy expenditure during starvation (no energy intake) can also be used to estimate energy balance in a whole-body calorimeter, in patients in intensive care units being artificially ventilated and by tracer techniques. The precision of these techniques varies from 1 to 10%. Establishing energy balance by measuring the discrepancy between energy intake and expenditure has to take into consideration the combined validity and reliability of both components. The measurement error for dietary intake may be as low as 2–3% in carefully controlled environments, in which subjects are provided only with certain food items and bomb calorimetry can be undertaken on duplicate samples of the diet. Reliable results can also be obtained in hospitalised patients receiving enteral tube feeding or parenteral nutrition as the only source of nutrition. Unreliability increases to an unknown extent in free-living subjects eating a mixed and varied diet; thus, improved methodology is needed for the study of energy balance.

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