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Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport Supplements

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A variety of dietary choices are marketed to enhance glycogen recovery after physical activity. Past research informs recommendations regarding the timing, dose, and nutrient compositions to facilitate glycogen recovery. This study examined the effects of isoenergetic sport supplements (SS) vs. fast food (FF) on glycogen recovery and exercise performance. Eleven males completed two experimental trials in a randomized, counterbalanced order. Each trial included a 90-minute glycogen depletion ride followed by a 4-hour recovery period. Absolute amounts of macronutrients (1.54 ± 0.27 g·kg-1 carbohydrate, 0.24 ± 0.04 g·kg fat-1, and 0.18 ± 0.03g·kg protein-1) as either SS or FF were provided at 0 and 2 hours. Muscle biopsies were collected from the vastus lateralis at 0 and 4 hours post exercise. Blood samples were analyzed at 0, 30, 60, 120, 150, 180, and 240 minutes post exercise for insulin and glucose, with blood lipids analyzed at 0 and 240 minutes. A 20k time-trial (TT) was completed following the final muscle biopsy. There were no differences in the blood glucose and insulin responses. Similarly, rates of glycogen recovery were not different across the diets (6.9 ± 1.7 and 7.9 ± 2.4 mmol·kg wet weight- 1·hr-1 for SS and FF, respectively). There was also no difference across the diets for TT performance (34.1 ± 1.8 and 34.3 ± 1.7 minutes for SS and FF, respectively. These data indicate that short-term food options to initiate glycogen resynthesis can include dietary options not typically marketed as sports nutrition products such as fast food menu items.
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Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Note: This article will be published in a forthcoming issue of the
International Journal of Sport Nutrition and Exercise
Metabolism. This article appears here in its accepted, peer-
reviewed form; it has not been copyedited, proofed, or formatted
by the publisher.
Section: Original Research
Article Title: Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly
Different Between Fast Food and Sport Supplements
Authors: Michael J. Cramer1, Charles L. Dumke1, Walter S. Hailes2, John S. Cuddy2, and Brent
C. Ruby1,2
Affiliations: 1Department of Health and Human Performance; 2The Montana Center for Work
Physiology and exercise Metabolism; The University of Montana, Missoula, MT.
Running Head: Similar outcomes for sport supplements and fast food
Journal: International Journal of Sport Nutrition and Exercise
Acceptance Date: February 5, 2015
©2015 Human Kinetics, Inc.
DOI: http://dx.doi.org/10.1123/ijsnem.2014-0230
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
POST-EXERCISE GLYCOGEN RECOVERY AND EXERCISE PERFORMANCE IS
NOT SIGNIFICANTLY DIFFERENT BETWEEN FAST FOOD AND SPORT
SUPPLEMENTS
SIMILAR OUTCOMES FOR SPORT SUPPLEMENTS AND FAST FOOD
Michael J. Cramer*
32 Campus Drive, McGill Hall
Missoula, MT 59812
Charles L. Dumke, FACSM*
32 Campus Drive, McGill Hall
Missoula, MT 59812
Walter S. Hailes**
32 Campus Drive, McGill Hall
Missoula, MT 59812
John S. Cuddy**
32 Campus Drive, McGill Hall
Missoula, MT 59812
Brent C. Ruby, FACSM*,**
brent.ruby@mso.umt.edu
406-243-2117
32 Campus Drive, McGill Hall
Missoula, MT 59812
*Health and Human Performance Department, The University of Montana
**The Montana Center for Work Physiology and Exercise Metabolism, The University of
Montana
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Abstract
A variety of dietary choices are marketed to enhance glycogen recovery after physical
activity. Past research informs recommendations regarding the timing, dose, and
nutrient compositions to facilitate glycogen recovery. This study examined the effects of
isoenergetic sport supplements (SS) vs. fast food (FF) on glycogen recovery and
exercise performance. Eleven males completed two experimental trials in a
randomized, counterbalanced order. Each trial included a 90-minute glycogen depletion
ride followed by a 4-hour recovery period. Absolute amounts of macronutrients (1.54 ±
0.27 gkg-1 carbohydrate, 0.24 ± 0.04 gkg fat-1, and 0.18 ± 0.03gkg protein-1) as either
SS or FF were provided at 0 and 2 hours. Muscle biopsies were collected from the
vastus lateralis at 0 and 4 hours post exercise. Blood samples were analyzed at 0, 30,
60, 120, 150, 180, and 240 minutes post exercise for insulin and glucose, with blood
lipids analyzed at 0 and 240 minutes. A 20k time-trial (TT) was completed following the
final muscle biopsy. There were no differences in the blood glucose and insulin
responses. Similarly, rates of glycogen recovery were not different across the diets
(6.9 ± 1.7 and 7.9 ± 2.4 mmolkg wet weight 1hr-1 for SS and FF, respectively). There
was also no difference across the diets for TT performance (34.1 ± 1.8 and 34.3 ± 1.7
minutes for SS and FF, respectively. These data indicate that short-term food options to
initiate glycogen resynthesis can include dietary options not typically marketed as sports
nutrition products such as fast food menu items.
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Introduction
It is common knowledge that muscle glycogen stores can be significantly
replenished when dietary carbohydrate (CHO) sources are ingested following a
glycogen depleting bout of exercise (Bergstrom & Hultman, 1966). The positive
relationship between initial muscle glycogen stores and work time to exhaustion
(Ahlborg et al., 1967) has led to the present dogma that exercise performance
necessitates an emphasis on muscle glycogen.Research has continued to demonstrate
that regular CHO feedings after glycogen depletion enhance muscle glycogen
resynthesis (Rotman et al., 2000; Tarnopolsky et al., 1997) and endurance performance
(Ivy et al., 2003). Additional emphasis has been placed on macronutrient
composition/ratios (Blom et al., 1987; Burke, Collier, & Hargreaves, 1993;; Zawadzki,
Yaspelkis, & Ivy, 1992), the amount of macronutrient (Ivy, Lee, et al., 1988;), and timing
of ingestion (Ivy et al., 2002;) to assist athletes, clinicians, and coaches in exercise
recovery and performance efforts.
Carbohydrate composition (glucose, fructose, and sucrose) and varying levels of
glycemic index (GI) have demonstrated subtle impact on overall rates of muscle
glycogen resynthesis (Beavers & Leutholtz, 2008; Blom et al., 1987; Burke, Collier, &
Hargreaves, 1993; R. Jentjens & Jeukendrup, 2003). Collectively, these data have
emphasized the concept of sports supplements as the preferred nutritional approach to
facilitate glycogen recovery. In contrast, the use of chocolate milk has gained
recognition as an alternative to traditional sport supplement products for glycogen
recovery (Karp et al., 2006; Roy, 2008; Shirreffs, Watson, & Maughan, 2007; Thomas,
Morris, & Stevenson, 2009).
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
While fast food is often viewed as a barrier to the prevention and treatment of
obesity in children (Bonnet et al., 2014), sensible menu items may offer a more
economical approach to glycogen recovery compared to costly sports supplements.
Moreover, there appears to be two major stigmas associated with fast food. The first
links fast food to unhealthy eating, childhood obesity, and poor nutritional choices while
the second categorizes fast food ingredients as low quality. In contrast, the nutritional
value and ingredient quality of sports supplemental food items goes mostly
unchallenged because of marketing perceptions and a link to regular physical
activity/exercise training.
The purpose of this study was to investigate the efficacy of fast food dietary
sources for glycogen recovery compared to common sport supplement
foods/beverages. We hypothesized that commonplace fast food options can provide
adequate macronutrient needs to restore muscle glycogen and that the potential
benefits will not be different from an approach using sport supplement products.
Methods
Participants
Eleven recreationally active male participants (n = 11) completed this randomized
cross-over study design. Participants were healthy, injury-free and familiar with
moderate to high intensity exercise (27.7 ± 6.3 years, 180 ± 8 cm, 76.8 ± 10.2 kg, 10 ±
5% fat, 4.2 ± 0.4 LO2min-1, 309 ± 32 wattmax). Prior to data collection, each participant
completed a Physical Activity Readiness Questionnaire (PAR-Q) and provided informed
consent. All procedures were approved by the University Institutional Review Board.
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Preliminary Testing
All preliminary testing was completed during the same initial visit after a minimum
4-hour fast. Body composition was estimated using hydrodensitometry. Underwater
weight was measured using an electronic strain-gauge scale (Exertech, Dreshbach,
MN) with estimated residual lung volume (Goldman & Becklake, 1959). Body density
was calculated using underwater weight and transposed to body composition using the
Siri equation (Siri, 1993).
Peak oxygen uptake (VO2peak) and maximal power output (Wmax) were
determined in the laboratory on a cycle ergometer (Velotron, RacerMate Inc., Seattle,
WA). Participants completed a graded exercise protocol starting at 95 watt, increasing
35 watt every 3 min until volitional fatigue. Expired gases were analyzed using a
calibrated metabolic cart (ParvoMedics, Inc., Salt Lake City, UT). VO2peak was
determined as the highest fifteen second average oxygen uptake during the test.
Maximum power output was calculated by adding the power output (watt) of the last
completed stage to the time in the stage volitional fatigue was achieved multiplied by 35
watt. For example, each minute of each stage was assumed to be equivalent to 11.67
watt (35•0.334 = 11.67).
In addition to the measure of VO2peak, participants completed two practice (PTT)
20km time trials (TT) on the same cycle ergometer on two separate days to ensure TT
competency prior to the completion of the experimental trials. Participants were verbally
instructed to complete the distance as quickly as possible and were allowed the
flexibility of shifting gears electronically. Distance and time were measured using the
RacerMate Inc. software. (RacerMate, Inc., Seattle, WA).
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Experimental Design
Participants completed two trials with seven days between each trial in a
randomized crossover design. Trials included the consumption of sport supplement
products (SS) or fast food menu items (FF) during a 4-hour recovery period after a
glycogen depletion ride. A 20km TT followed the recovery period to evaluate exercise
performance. Participants were instructed to abstain from exercise and keep a dietary
record of all food and drink consumed 24-hours prior to each trial. Participants were
instructed to duplicate this diet for the second trial to minimize differences in resting
muscle glycogen levels. The morning of each trial, participants arrived at the lab
following a 12-hour fast. Each participant completed the 90-minute glycogen depleting
exercise using the above mentioned cycle ergometer. The protocol included a 10-
minute warm up at 55% Wmax followed by a series of 10 intervals (2-minutes at 80%
Wmax followed by 4-minutes at 50% Wmax). After the interval series, participants
completed 8-minutes at 60% Wmax followed by a final 12-minutes at 50% Wmax. Water
consumption was ad libitum. Following the 90-minute cycling trial, participants rested in
a reclined/seated position during a 4-hour recovery period and adhered to a prescribed
feeding schedule. Following the 4-hour recovery period, participants completed the
20km TT on the same cycle ergometer as described above.
Feeding Strategy
Participants consumed absolute amounts of macronutrients as either SS or FF at
0 and 2-hours of recovery. All food items were weighed for accuracy in conjunction with
nutrition label serving sizes. Participants consumed the same food items, which
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
amounted to 1.54 ± 0.27, 0.24 ± 0.04, and 0.18 ± 0.03 gkg-1 for carbohydrate, fat, and
protein, respectively. Table 1.1 and 1.2 illustrate the detailed menu items.
Muscle Biopsies
Muscle biopsies of the vastus lateralis muscle were performed at 0 and 4-hours
of recovery using the percutaneous biopsy needle technique with the aid of suction
(Evans, Phinney, & Young, 1982). One milliliter of 1% lidocaine was injected directly
beneath the skin to anesthetize an area approximately 2 cm2, then an additional 2-3 ml
of 1% lidocaine preparation was injected near the location of the fascia. Adrenaline was
not used in combination with the lidocaine. Following the lidocaine injection a small
(approximately 0.5 cm) incision was made through the skin and muscle fascia. The
Bergstrom biopsy needle was then inserted through the incisions into the belly of the
vastus laterals muscle, removing approximately 30mg of tissue. Excess blood, fat, and
connective tissue were immediately removed. Tissue samples were frozen in liquid
nitrogen and stored in a freezer at -80C for later muscle glycogen analyses. The 4-hour
biopsy was taken from a site approximately 2 cm proximal to the initial 0-hour biopsy
location. Second trial biopsies were taken from the opposite leg and leg order was
randomized across trials.
Blood Sampling
Blood samples were obtained from an antecubital arm vein using a venipuncture
technique at scheduled intervals of 0, 30, 60, 120, 150, 180, and 240 min of recovery
(n=10). Samples were allowed to clot then spun at 4000 rpm for 15 minutes in a
refrigerated centrifuge (4°C) (Jouan Inc., MR22i). Serum was aliquoted into tubes and
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
stored at −30°C for later glucose and insulin analyses. Whole blood samples were
collected at 0 and 4 h of recovery and sent to Providence St. Patrick Hospital in
Missoula, MT for lipid analyses.
Questionnaire
Participants completed gastrointestinal discomfort questionnaires assessing
feelings of hunger, fullness, sickness, and stomach discomfort at 0, 1, 2, 3, and 4-hours
of recovery. A second post-meal questionnaire was administered at 0 and 2-hours of
recovery assessing meal satisfaction, taste, and acceptability. Questionnaires were
designed on a 150mm visual analogue scale (VAS) with “Not at all” on the left and
“Extremely” on the right end points. Participants placed an X along the continuum in
response to each question. Scores were reported as the distance from “Not at all” in
mm divided by 150mm. This technique has been previously used to evaluate dietary
impacts (Kissileff et al., 2003).
20km Time Trial
After recovery, participants performed a 20km TT on the same cycle ergometer
as described above (Velotron, RacerMate Inc., Seattle, WA). Participants were
instructed to complete the distance as quickly as possible and were allowed to shift
gears electronically. Verbal encouragement was not provided during any of the TT
testing segments.
Tissue and Blood Analysis
Two separate muscle samples (12.7±3.0 mg, obtained at the same time point)
were each analyzed in duplicate to determine muscle glycogen concentrations using an
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
enzymatic spectrophotometric method (Ruby et al., 2005). Samples were weighed and
placed in 0.5 ml of 2N HCl solution. Sample solutions were weighed, incubated in an
oven for two hours at 100°C, then re-weighed and re-constituted to their original weight
using distilled water. To normalize pH, 1.5 ml of 0.67 M NaOH was added. Then 100 μl
of the muscle extract solution was added to 1 ml of infinity glucose (HK) liquid stable
reagent (ThermoTrace Ltd.) and read on a spectrophotometer at 340 nm. Muscle
glycogen concentration was calculated using the extinction co-efficient of NADH.
Muscle glycogen concentrations are expressed in mmolkg-1 wet weight of muscle.
Blood samples were analyzed for glucose in triplicate using Infinity glucose (HK)
liquid stable reagent (ThermoTrace Ltd.) and read on a spectrophotometer at 340 nm.
Blood glucose concentration was calculated using the extinction co-efficient of NADH.
Samples were analyzed for insulin in duplicate using an enzymatic spectrophotometric
ELISA method (EIA-2935, DRG International). Serum lipid analyses were performed by
the laboratory at Providence St. Patrick Hospital (Missoula, MT). Samples were allowed
to clot for 30 minutes in serum separating tubes then spun at 2500G in a refrigerated
centrifuge (Beckman Coulter INC). Samples were then placed in a chemistry analyzer
for reading (Dimension Vista 500, Siemens). Mean intra-assay coefficient of variation for
muscle samples, glucose, and insulin was less than 5%.
Statistical Analysis
A two-tailed, paired t-test was used to compare rates of muscle glycogen
recovery (Microsoft Excel, Microsoft Corp., Redmond, WA). PTT and TT performance
times were analyzed using a one-way ANOVA with repeated measures (SPSS Inc.,
Chicago, IL). Muscle glycogen, blood glucose, serum insulin, blood lipids, and
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
questionnaire data were analyzed using a two-way ANOVA (trial × time) with repeated
measures (SPSS Inc., Chicago, IL). A probability of type I errors less than 5% was
considered significant (p<0.05). All data are reported as mean ± SD.
Results
Muscle Glycogen
We were unable to detect a statistically significant difference in muscle glycogen
concentration post-exercise when comparing SS and FF trials at 0 and 4-hours of
recovery (p>0.05). There was a main effect for time, demonstrating an overall increase
in muscle glycogen concentrations following the 4-hour recovery period (p<0.05, n=11)
(Figure 1). Similarly, the calculated rate of muscle glycogen recovery was not different
between diets (6.9 ± 1.7 and 7.9 ± 2.4 mmolkg wet weight-1hr-1 for the SS and FF
trials, respectively (p>0.05, n=11).
Blood Glucose
There was no difference for blood glucose concentrations between SS and FF
trials at 0, 30, 60, 120, 150, 180, and 240 minutes of recovery (p>0.05, n=10) (Figure 2).
There was a main effect for time, as blood glucose was elevated at 30 and 150 minutes
compared to time 0 (p<0.05, n=10).
Serum Insulin
There was no difference for serum insulin concentrations between SS and FF
trials at 0, 30, 60, 120, 150, 180, and 240 minutes of recovery (p> 0.05, n = 10) (Figure
2). There was a main effect for time, with serum insulin elevated at 30, 60, 150, and 180
minutes compared to time 0 (p < 0.05, n = 10).
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Blood Lipids
There was no difference between SS and FF trials for total cholesterol, high-
density, low-density lipoproteins, and triglycerides at 0 hours and 4 hours post-exercise
(Table 2). There was a main effect for time, which demonstrated that CHOL, HDL, and
LDL were lower 4 hours post-exercise compared to time 0 (p<0.05, n=10)
20k Time Trial
There was no difference in TT performance between PTT and the experimental
trials (34.3 ± 2.1, 34.5 ± 1.9, 34.1 ± 1.8, and 34.3 ± 1.7 minutes for PTT1, PTT2, SS,
and FF trials, respectively, p>0.05, n = 11).
Questionnaire
There was no difference for feelings of sickness and discomfort between the
trials observed at 0, 1, 2, 3, and 4 hours of recovery (p>0.05, n=11). Hunger displayed a
main effect for time with scores of 42 ± 8, 64 ± 6, 28 ± 6, 53 ± 7, and 72 ± 6 millimeters
at 0, 1, 2, 3, and 4 hours of recovery, respectively. (p<0.05, n = 11). Hunger was higher
at 4 hours compared to time 0 hours of recovery. Participants reported being more full
during the SS compared to FF immediately after the 2-hour feeding (108 ± 33 vs. 75 ±
42mm, respectively, interaction effect, p<0.05, n=11). No difference was observed for
perceived meal taste and acceptability after 0 and 2-hour feedings (p>0.05, n=11).
There was no difference between the diets for feelings of satiety after 0 and 2 hour
feedings, but the FF meal was more satisfying at 2 hours compared to the initial 0 hour
FF meal (78 ± 32 vs. 52 ± 27mm, respectively, interaction effect, p<0.05, n=11).
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Discussion
This protocol was designed to evaluate the impacts of non-traditional sport
nutritional choices on recovery, specifically glycogen recovery, and subsequent exercise
performance. This was accomplished by matching macronutrient composition from fast
food menu items with commercially available sport nutrition products used for the 0 and
2 hour post-exercise feedings. Primary findings demonstrate that muscle glycogen
recovery and exercise performance were not different when comparing products
created specifically for sport recovery and traditional fast food. These data are novel in
demonstrating effective glycogen recovery benefits from fast food menu items
comparable to products most often advertised as a practical option to optimize glycogen
recovery.
A wide range of feeding strategies have been implemented (macronutrient
composition, amount, and timing of ingestion) so as to develop specific suggested
guidelines to enhance immediate glycogen resynthesis (Ivy, 1998; Ivy et al., 2002; Ivy,
Katz, et al., 1988; R. Jentjens & Jeukendrup, 2003; Reed et al., 1989). Optimal
glycogen recovery recommendations are 1.2gkg-1 CHO every hour, ingested in regular
intervals of ≤30 minutes (R. Jentjens & Jeukendrup, 2003; van Loon et al., 2000). This
study chose to utilize a 2-hour interval feeding strategy as suboptimal, real-world
application of recovery strategies where environment, nutrient source availability, and
total amount of nutrient source ingestion may hinder adherence to optimal recovery
recommendations. Administration of CHO immediately after exercise has been shown
to improve glycogen recovery by 45% versus delayed feedings and is further enhanced
with the addition of a 2-hour feeding (Ivy, Katz, et al., 1988). However, if feeding is
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
provided prior and during extended exercise, the inclusion of a carbohydrate/protein
recovery product immediately post-exercise does not enhance rates of glycogen
recovery compared to a 2-hour delayed feeding (Reinert et al., 2009). Carbohydrate
amount used in the present study of 1.54 ± 0.27g·kg-1 was in accordance with previous
studies suggesting a plateau of glycogen recovery between feedings of 0.7 and 3.0g·kg-
1 administered in two hour intervals (Blom et al., 1987; Ivy, Lee, et al., 1988; R. L.
Jentjens et al., 2001; Reinert et al., 2009). In addition, muscle glycogen recovery rates
of 6.9 ± 1.7 and 7.9 ± 2.4 mmol·kg wet weight1·hr-1 for SS and FF, respectively, are
comparable to previous research of 4.1-10.6 mmol·kg wet weight1·hr-1 given a variety
of modalities, environments and feeding strategies (Gillum, Dumke, & Ruby, 2006;
Naperalsky, Ruby, & Slivka, 2010; Reinert et al., 2009; Ruby et al., 2005).
While the presence of protein in the form of essential amino acids (EAA)
enhances muscle glycogen recovery in conjunction with a moderate amount of CHO
(approximately 0.8g•kg-1hr-1), protein added to a high CHO supplement (1.2gkg-1hr-1)
does not further increase glycogen recovery rates (R. L. Jentjens et al., 2001). Although
the inclusion of additional protein and/or novel amino acids may alter short-term rates of
glycogen recovery (Ivy et al., 2002; Ruby et al., 2005), the present data demonstrate
that the sources of carbohydrate and protein (1.54 ± 0.27 and 0.18 ± 0.03 gkg-1
respectively) from fast food result in comparable rates of glycogen synthesis.
The present blood response data demonstrates a rapid rise in blood glucose and
insulin 30-minutes following each feeding with a concomitant return to baseline by 60-
minutes post feeding. This is comparable to prior research using varied strategies in
the carbohydrate dose (Ivy, Lee, et al., 1988), feeding intervals (Ivy, Katz, et al., 1988),
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
and type of feedings (Ivy et al., 2002). The near identical response patterns for glucose
and insulin with the two diets highlight the lack of difference between diets in terms of
digestion, absorption and ultimately CHO delivery to the muscle.
While it is commonly hypothesized that the chronic consumption of fast food
choices have a negative effect on dyslypemia, cardiovascular risk, and obesity (Grundy
& Denke, 1990), the acute consumption has received little attention in the literature
when applied to young, active individuals. Furthermore, fast food sources matched
isoenergetically to sports supplements can provide for basic recovery needs of the
muscle and may offer a convenient and economical approach to glycogen recovery
under some circumstances.
Acknowledgments
The authors thank the participants for their investment of time and energy to the project.
The authors also thank Audrey Elias, Tim Hampton, Emily Simpson, and Tucker
Squires for their contributions during data collection.
Authors’ Contributions
MJC participated in conception, design, data acquisition, assisted in muscle glycogen,
blood parameter, questionnaire, and TT analysis and interpretation of data, and wrote
the manuscript. CLD participated in conception, design, assisted in muscle glycogen,
blood parameter, questionnaire, and TT analysis and interpretation of data, and aided in
the drafting and revising of the manuscript. JSC participated in conception, design, data
acquisition, analysis and interpretation of data, and aided in the drafting and revising of
the manuscript. WSH participated in conception, design, data acquisition, analysis and
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
interpretation of data, and aided in the drafting and revising of the manuscript. BCR
participated in conception, design, and data acquisition, assisted in analysis and
interpretation of data, and aided in the drafting and revising of the manuscript. All
authors have read and given final approval of this version of the manuscript for
publication.
Funding and Conflicts of Interest
The authors declare that they have no competing interests in access to these data or
associations with companies involved with products used in this research.
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
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International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
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Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
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Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Figure 1. Muscle glycogen concentration during recovery.
■SS, □FF *p<0.05 (n=11) main effect for time vs 0 hours. Values are mean ± SEM
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Figure 2. Blood glucose concentration during recovery.
----FF, SS *p<0.05 (n=10) main effect for time vs 0 hours. Values are mean ± SEM
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Figure 3. Serum insulin concentration during recovery.
----FF, SS *p<0.05 (n=10) main effect for time vs 0 hours. Values are mean ± SEM
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Table 2.1 Fast food feeding
Fast Food
0 hr
Energy
(kJ)
Fat
(g)
Cho
(g)
Pro
(g)
Qty
Sodium
(mg)
Hotcakes
1464
9
60
8
1
590
Hashbrown
628
9
15
1
1
310
Orange Juice (small)
628
0
34
2
1
0
Total
2720
18
109
11
900
2 hr
Hamburger
1046
9
31
12
1
480
Coke (medium)
837
0
54
0
1
45
Fries (small)
962
11
29
3
1
160
Total
2845
20
114
15
685
4 Hour Total
5565
38
223
26
1585
Table 2.2 Sport supplement feeding
Sport Supplement
0 hr
Energy
(kJ)
Fat
(g)
Cho
(g)
Pro
(g)
Qty
Sodium
(mg)
Gatorade (20 oz)
544
0
34
0
1
270
Kit's Organic PB
837
11
25
6
2
95
Cliff Shot Bloks (1 blok)
139
0
8
0
4
17
Total
2775
22
116
12
527
2 hr
Cytomax (1 scoop, 10 oz)
377
0
22
0
2
120
Power Bar Recovery
PBCC
1088
10
30
12
1
180
Power Bar Energy Chews
837
0
46
3
1
30
Total
2678
10
120
15
450
4 Hour Total
5453
32
236
27
977
Post-exercise Glycogen Recovery and Exercise Performance is Not Significantly Different Between Fast Food and Sport
Supplements” by Cramer MJ et al.
International Journal of Sport Nutrition and Exercise Metabolism
© 2015 Human Kinetics, Inc.
Table 3 Blood lipid profile for both trials (FF and SS) at the beginning (0 hour) and end
(4 hour) of recovery
FF
SS
0 hour
4 hour
0 hour
4 hour
CHOL(mg/dL)
173 ± 32
160 ± 34*
177 ± 28
164 ± 29*
TRIG(mg/dL)
106 ± 31
108 ± 53
112 ± 50
130 ± 102
HDL(mg/dL)
62 ± 15
56 ± 16*
62 ± 13
54 ± 12*
LDLc(mg/dL)
89 ± 27
83 ± 28*
93 ± 25
84 ± 29*
*p<0.05 (n=11) main effect for time vs 0 hours.
... When compared to sport nutrition products, food items have demonstrated success in promoting 4-h glycogen resynthesis rates. Both chocolate milk (Lunn et al. 2012) and fast food items (Cramer et al. 2015) restore glycogen similarly to common commercial sport nutrition products. Chocolate milk (Karp et al. 2006;Lunn et al. 2012;Pritchett et al. 2009; Thomas et al. 2009) and fast food (Cramer et al. 2015) also impact subsequent exercise performance similarly to commercial sport nutrition items. ...
... Both chocolate milk (Lunn et al. 2012) and fast food items (Cramer et al. 2015) restore glycogen similarly to common commercial sport nutrition products. Chocolate milk (Karp et al. 2006;Lunn et al. 2012;Pritchett et al. 2009; Thomas et al. 2009) and fast food (Cramer et al. 2015) also impact subsequent exercise performance similarly to commercial sport nutrition items. Collectively, these data demonstrate that a variety of dietary strategies can be effective in promoting glycogen re-synthesis following a bout of glycogen-depleting exercise. ...
... In the current study, males and females resynthesized muscle glycogen at similar rates following glycogen depletion and consumption of two different diets (potato-based food items and common sport supplement products), leading to minimal differences during subsequent exercise performance. When coupled with prior data using fast food items (Cramer et al. 2015), these recent data demonstrate that the exercise recovery carbohydrate oriented feeding recommendations given by health care providers, coaches and trainers can be simplified. Sport and tactical athletes of both sexes can choose a variety of desirable and/ or available carbohydrate sources as recovery foods/beverages. ...
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PurposeResearch has elucidated the impact of post-exercise carbohydrate nutrition and environmental conditions on muscle glycogen re-synthesis. However, research has minimally considered the implications of glycogen recovery in females and has mostly focused on commercial sport nutrition products. The purpose of this study was to determine the effects of varied mixed macronutrient feedings on glycogen recovery and subsequent exercise performance in both sexes.Methods Males (n = 8) and females (n = 8) participated in a crossover study. Subjects completed a 90-min cycling glycogen depletion trial, then rested for 4 h. Two carbohydrate feedings (1.6 g kg−1) of either sport supplements or potato-based products were delivered at 0 and 2 h post-exercise. Muscle biopsies (glycogen) and blood samples (glucose, insulin) were collected during the recovery. Afterwards, subjects completed a 20 km cycling time trial.ResultsThere was no difference between sexes or trials for glycogen recovery rates (male: 7.9 ± 2.7, female: 8.2 ± 2.7, potato-based: 8.0 ± 2.5, sport supplement: 8.1 ± 3.1 mM kg wet wt−1 h−1, p > 0.05). Time trial performance was not different between diets (38.3 ± 4.4 and 37.8 ± 3.9 min for potato and sport supplement, respectively, p > 0.05).Conclusions These results indicate that food items, such as potato-based products, can be as effective as commercially marketed sports supplements when developing glycogen recovery oriented menus and that absolute carbohydrate dose feedings (g kg−1) can be effectively applied to both males and females.
... These data suggest that the provision of higher CHO-containing food and drink options (25-40 g/h) and consuming them on the go while working, is a beneficial and practical approach to optimize work shift performance and may confer improved operational resilience and potentially safety. From these experiments and subsequent experimental studies (32,45), there appears to be a wide variety of food options that could be used to support muscle CHO needs (commercially available sport-marketed liquids and food bars in combination with regular food items). This empirically driven conclusion is important in that it de-emphasizes the need for an exclusive supplement-oriented product. ...
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Wildland firefighters (WLFFs) are inserted as the front-line defense to minimize loss of natural resources, property, and human life when fires erupt in forested regions of the world. The WLFF occupation is physically demanding as exemplified by total daily energy expenditures that can exceed 25 MJ/day (6000 calories). WLFFs must also cope with complex physical and environmental situations (i.e., heat, altitude, smoke, compromised sleep, elevated stress) which challenge thermoregulatory responses, impair recovery, and increase short- and long-term injury/health risks while presenting logistical obstacles to nutrient and fluid replenishment. The occupation also imposes emotional strain on both the firefighter and their families. The long-term implications of wildfire management and suppression on the physical and mental health of WLFFs are significant, as the frequency and intensity of wildland fire outbreaks as well as the duration of the fire season is lengthening and expected to continue to expand over the next three decades. This article details the physical demands and emerging health concerns facing WLFFs, in addition to the challenges that the U.S. Forest Service and other international agencies must address to protect the health and performance of WLFFs and their ability to endure the strain of an increasingly dangerous work environment. © 2023 American Physiological Society. Compr Physiol 13:4587-4615, 2023.
... There were no differences in muscle glycogen synthesis rate or time-trial performance between the CHO sources [72]. Cramer et al. [73] also showed no difference in muscle glycogen synthesis rates and 20 km TT endurance performance between a high-CHO fast-food diet and CHO supplements ingested during the 4 h recovery period between two exercise bouts. These data suggest that the ingestion of CHO-rich foods, such as potatoes, is equally effective for the recovery of muscle glycogen and subsequent exercise performance as traditional CHO supplements (Table 3). ...
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Citation: Naderi, A.; Gobbi, N.; Ali, A.; Berjisian, E.; Hamidvand, A.; Forbes, S.C.; Koozehchian, M.S.; Karayigit, R.; Saunders, B. Carbohydrates and Endurance Exercise: A Narrative Review of a Food First Approach. Nutrients 2023, 15, 1367. https://doi. Abstract: Carbohydrate (CHO) supplements such as bars, gels, drinks and powders have become ubiquitous as effective evidence-based CHO sources that improve endurance exercise performance. However, athletes are increasingly turning to more cost-effective 'food-first' approaches for CHO ingestion to improve exercise performance. Mixed CHO foods including cooked lentils, oats, honey, raisins, rice, and potatoes are all effective pre-exercise CHO food sources. Caution is advised when selecting some of these foods as a primary CHO source, as some athletes may be prone to gastrointestinal discomfort-especially regarding those foods where the quantities required for recommended CHO intake may be voluminous (e.g., potatoes). Palatability may be another barrier to the ingestion of some of these CHO-rich foods. Although most of these CHO-rich foods appear effective for exercise performance or recovery when consumed pre-and post-exercise, not all are viable to ingest during exercise due to difficulties in the quantities required, transport, and/or gastrointestinal discomfort. Raisins, bananas and honey may be particularly useful CHO foods for consumption during exercise, as they are easily transportable. Athletes should trial CHO food sources before, during and/or following training before implementation during competition.
... Also, coconut water versus carbohydrate electrolyte was tested for hydration parameters (body mass, fluid retention, plasma osmolality, urine specific gravity) and performance on a treadmill exercise until exhaustion (Kalman et al. 2012), and showed similar results to protein and carbohydrate drink based on cocoa versus a beverage containing protein and carbohydrates added with natural cocoa, varying flavonols content for the variables CK, and perceiving soreness in muscle function (Peschek et al. 2013). Even different fasting foods were investigated and showed to have a similar effect on glycogen resynthesizing parameters when compared to different types of supplements (Cramer et al. 2015). Furthermore, commercial supplements were not superior to foods in any of the 16 studies. ...
Article
In recent years, there have been studies in the literature reporting the ergogenic effect of some different foods on sports performance. Given the reasonable number of studies in which some food has shown improvement in some physiological variables related to physical performance, a review is pertinent in order to produce a compilation of these studies, providing new elements for athletes and coaches which aim to optimize their performance. Thus, the objective of this work was to present a systematic review of the findings regarding the potential ergogenic effect of food for athletes. Researchers performed a double-blind research in Medline/PubMed considering articles published until January 2019 which resulted in 71 articles. Increased time until exhaustion, improved aerobic capacity and strength recovery were the most commonly reported physical effects. In general, food showed equal or superior ergogenic activity over supplements. Although the number of foods investigated is reasonable, there is still no body of evidence for each studied food, except beets. The current data support the possibility of certain foods being able to enhance athletic performance, as well as serving as an energy source. However, a larger volume of studies is needed to form a body of evidence on each of these foods.
... The amount of CHO (25-312 g) consumed prior to exercise does not have a meaningful influence on time trial performance [5,52,53,55], while the glycemic index appears to have only a small impact that is more likely to be observed in time-to-exhaustion, but not time-trial performance tests [132]. No differences in performance have been observed following pre-exercise ingestion of solid vs. liquid CHO [43], solid vs. gel-based CHO [133,134], or fast-food vs. sport supplements [135]. Timing of the pre-exercise meal has minimal effects when consumed 15, 45, or 75 min [61], 15 or 60 min [129], or 5 or 35 min [58] before exercise, but CHO ingested 30 min before exercise resulted in better performance than 120 min before exercise [67]. ...
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The primary variables influencing the adaptive response to a bout of endurance training are exercise duration and exercise intensity. However, altering the availability of nutrients before and during exercise can also impact the training response by modulating the exercise stimulus and/or the physiological and molecular responses to the exercise-induced perturbations. The purpose of this review is to highlight the current knowledge of the influence of pre-exercise nutrition ingestion on the metabolic, physiological, and performance responses to endurance training and suggest directions for future research. Acutely, carbohydrate ingestion reduces fat oxidation, but there is little evidence showing enhanced fat burning capacity following long-term fasted-state training. Performance is improved following pre-exercise carbohydrate ingestion for longer but not shorter duration exercise, while training-induced performance improvements following nutrition strategies that modulate carbohydrate availability vary based on the type of nutrition protocol used. Contrasting findings related to the influence of acute carbohydrate ingestion on mitochondrial signaling may be related to the amount of carbohydrate consumed and the intensity of exercise. This review can help to guide athletes, coaches, and nutritionists in personalizing pre-exercise nutrition strategies, and for designing research studies to further elucidate the role of nutrition in endurance training adaptations.
... This result was comparable to several similarly designed studies that employed a glycogen lowering exercise, a 4-h recovery period with or without CHO and a performance test. [13][14][15][16][17] It is assumed in these studies that muscle glycogen synthesis contributed to the maintenance of performance in the subsequent exercise bouts, but many studies also demonstrated higher blood glucose concentrations during the recovery period when ingesting CHO. ...
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Purpose: This study tested whether CHO intake during a 2-h rest between exercise bouts improved performance in the subsequent bout. Methods: In a randomized, single-blinded, crossover design, 10 recreationally-active participants (23 ± 4 yr, 70.8 ± 6.6 kg, VO2peak:47.0 ± 5.4 mL O2·min-1·kg body mass-1) arrived at the lab post-prandial and completed 2 exercise bouts separated by 2-h rest. Bouts included 5 x 4-min intervals at ~80% VO2peak separated by 2-min at ~40% VO2peak and ended with an endurance trial (ET) to voluntary exhaustion at ~90% VO2peak. During intervals 1 and 4 in each bout expired gases were collected and O2 deficit was estimated. Immediately following bout-1, either a CHO (1.2 g CHO·kg body mass-1) or placebo (PL) solution was consumed. Results: ET duration decreased in bout-2 vs. 1 in both conditions (P<0.01) but was ~35% longer in bout-2 with CHO vs. PL (Interaction, P=0.03; post-hoc, P=0.03). VO2 increased during interval 4 vs. 1 in both bouts (P<0.01) but was unaffected by CHO (P≥0.58). O2 deficit was unaffected by CHO (P=0.93), bout or interval (P≥0.15). Perceived exertion was higher in bout-2 vs. 1 (P<0.001) and reduced in intervals 2 and 4 in CHO (P≤0.01). Conclusions: When rest between training sessions is 2 hours, athletes may improve subsequent performance by consuming CHO during recovery. Supported by NSERC, Canada.
... Solid and liquid forms of carbohydrates are associated with similar rates of glycogen synthesis, 108-109 so athletes can meet their daily carbohydrate needs by consuming the carbohydrate-rich foods and beverages they most enjoy. Interestingly, Cramer et al. 110 showed that fast foods (in 2 meals, including 1 meal with french fries) were similar to sports supplements of similar carbohydrate and energy content in promoting muscle glycogen resynthesis in the 4 hours following 90 minutes of glycogen-depleting cycling exercise. ...
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THE CLASSIFICATION OF CARBOHYDRATES (CHO) BASED ON GLYCEMIC INDEX (GI), ALTHOUGH CLINICALLY USEFUL, MAY LACK PRACTICAL UTILITY IN SPORT AS THE AMOUNT OF CHO INGESTED ALSO AFFECTS CIRCULATING BLOOD SUGAR. IN ATTEMPT TO CAPTURE THE ENTIRE GLUCOSE RAISING POTENTIAL OF DIETARY CARBOHYDRATES, THE CONCEPT OF GLYCEMIC LOAD (GL) HAS BEEN INTRODUCED TO INCORPORATE BOTH THE QUALITY AND THE QUANTITY OF CHO CONSUMED. THIS REVIEW DISCUSSES CURRENT RESEARCH IN THE AREA OF GI AND GL, WITH EMPHASIS PLACED ON THE ROLE OF GL IN GUIDING ATHLETE'S DIETARY FOOD CHOICES PRE, DURING, AND POST EXERCISE.
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The purpose of this study was to determine the effects of a recovery beverage immediately after exercise on rates of muscle glycogen resynthesis in response to road cycling when nutritional supplementation was supplied during exercise and a solid meal was served two hours after exercise. Eight trained male cyclists, (25+/-4 years, 69.3+/-5.2 kg, VO2 peak=4.5+/-0.4 L.min(-1)) performed two 62 km outdoor training rides in a double-blind, randomized cross-over experiment. Subjects received a food bar and a commercial sport drink during each ride. A recovery beverage (40 g CHO+20 g PRO) or a placebo (PL) was administered 30 min post-exercise. At 2 h post-exercise, a solid meal was provided for both trials. There was no difference between trials at any time point for glycogen (140+/-9, 56+/-8, and 70+/-8 mmol.kg(-1)wet wt.(-1).hr.(-1) for pre, post, and 4 h post, respectively). The addition of a supplemental recovery beverage ingested soon after exercise did not significantly increase the rate of muscle glycogen resynthesis after 4 h of recovery when nutritional supplementation is provided during exercise and a meal is consumed 2 h after exercise.