London Chaffee
EXSC 320-003
Annotated Bibliography
Professor Peveler
Annotated Bibliography
1. Anderson, L, Orme, P, Naughton, RJ, Close, GL, Milsom, J, Rydings, D, O’Boyle, A,
Do Michele, R, Louis, J, Hambly, C, Speakman, JR, Morgans, R, Drust, B, Morton,
JP. Energy intake and expedeutire of professional soccer players of the English
premier league: Evidence of carbohydrate periodization. International Journal of
Sport Nutrition and Exercise Metabolism 27(3): 228-238, 2017.
Introduction:
Study used a double labeled water method over a 7-day in session period.
Energy expenditure (EE) may vary accordingly and hence, energy intake (EI)
The purpose of this study was to simultaneously quantify EI, EE, training load
and match load in professional soccer player
Methods:
Subjects were 6 male professional soccer players.
This study was during the months November and December
Pitch based training sessions were monitored using portable global positioning
systems.
Following collection of baseline samples, players were administered orally with a
single bolus dose of hydrogen (deuterium 2H) and oxygen (18O) stable isotopes
in the form of water (2H2 18O).
Approximately every 24-hr, when players entered the training ground (or hotel on
the morning of game 2) they were weighed and provided a urine sample in a 35
ml tube.
Self-reported EI was assessed from 7-day food diaries for all players and reported
in kilocalories (kcal) and kilocalories per kilogram of lean body mass.
Throughout the duration of this study, meals were consumed at the club’s training
ground or home ground, a nearby hotel
On days 3 and 6 the players were provided with breakfast and lunch.
On days 1 and 4 the players were provided with lunch and dinner.
On day 2 the players were provided with breakfast at the training round and lunch
and prematch meal.
On day 5 the players were provided with breakfast and prematch meal.
On day the players were provided with lunch and post training snacks.
Daily energy and macronutrient intake were analyzed using one-way repeated-
measures ANOVAs.
The normal distribution of differences between data pairs was verified with
Shapiro-Wilk tests
Used to assess the differences between the average daily EI and EE, the difference
between CHO intake during training and matches, the difference between EI and
CHO intake on match days vs. training days, and changes in body mass from
before to after the study period.
Results:
There were no significant differences (p = .16; see Table 3) between average daily
EE (3566 ± 585 kcal) and EI
The players body mass did not significantly change
Discussion:
The data suggest that elite players’ daily energy expenditure can range from 3047
to 4400 kcal per day
Players also practice elements of CHO periodization such that absolute daily
CHO intake and exogenous CHO feeding i
Daily absolute and relative EI and CHO intake were significantly different across
the 7-day period.
Players reported greater absolute and relative EI on day compared with days 1 and
3.
Day 5 the players reported higher absolute and relative EI compared with days 1,3
and 4 and 6.
Players reported higher absolute and relative EI on day 7 compared to day 4.
The mean quantity of CHO consumed during the two competitive matches (32.3 ±
21.9 g.h-1; Player 1–6 data: 25.1, 24.8, 70.9, 29.9, 38.3 and 4.9 g.h-1,
respectively) was significantly higher (p < .05) than that consumed during training
sessions
CHO consumed was provided from gels and fluid.
2. Cermak, NM, van Loon, LJC. The use of carbohydrates during exercise as an
ergogenic aid. 43(11): 1139-1155, 2013.Auckland
Introduction:
Fat dominates as a preferred fuel source, but with an increase in exercise intensity,
CHO oxidation is greater with muscle glycogen being the most important
substrate source.
Muscle glycogen is an essential fuel source during prolonged moderate to high
intensity exercising.
Different types of CHO may be oxidized at various rates during prolonged
exercise.
Ingesting CHO solutions during sports requiring intermittent bouts of high
intensity exercise (with a duration [45 to 60 min) may prove beneficial by
attenuating decrements that may occur towards the later stages of a game.
Conclusion:
CHO ingestion during prolonged moderate to high intensity exercise is essential
for optimal performance for endurance athletes.
Exercise lasting no longer than 3 h, a modest amount of carbohydrate should be
ingested (60 gh-1 ).
For events lasting longer than 2.5 h, up to 90 g carbohydrateh-1 can be
metabolized by well-trained athletes.
For short duration, high-intensity exercise lasting approximately 30–75 min, a
carbohydrate mouth rinse (or ingestion) with minimal amounts of carbohydrate
may prove to be useful.
Athletes are encouraged to consume 75–90 g carbohydrate per hour for 4–6 h
after cessation of exhaustive exercise.
3. Fernandes, HS. Carbohydrate consumption and periodization strategies applied to
elite soccer players. Current Nutrition Reports 9(1): 414-419, 2020.
Introduction:
Soccer is a short duration and high intensity sport alternating with longer duration
and lower intensity bouts.
Also, intense physical contact which is more than 70% walking and 20% intense
action.
Adaptive training response is determined by exercise type and training load,
manipulating glycogen storage, and CHO intake during high and low-intensity
periods.
Purpose of this review was to provide a holistic view of CHO periodization and
its effects on sports performance and recovery with professional soccer players.
Caloric Expenditure and Intake:
CHO are important for sports performance because they are the main substrate for
energy production during moderate- to high-intensity exercise.
A study showed that the total energy intake was higher on match days compared
to training days.
Daily CHO intake was higher on game days compared to training days.
CHO Supplementation Before Match:
Athletes should start matches with full glycogen storage.
Recommendations are to ingest CHO from 1-4 grams, 1-4 hours before exercise.
Researchers found that after athletes has a CHO rich meal 3 hours before the
game, they found that this induced a 10% increase in muscle glycogen.
Another study showed platers intaking 70 grams of CHO approximately 2 hours
before the game, resulted in increased dribbling speed.
CHO Supplementation During the Match:
Sport drinks that have 1.5 grams of CHO every 25 mL of water can be used as a
mouth rinse and supply CHO for the athlete.
Researchers demonstrated that consuming 12% CHO solution at the end of the
warm-up and at halftime can improve sprinting, acceleration, dribbling speed, and
cognition compared with consuming water only.
The Importance of CHO Periodization Strategies:
The “train low, compete high” strategy consists of training with low CHO
availability at appropriate exercise intensity.
The “sleep low” strategy has been shown to improve exercise-induced adaptations
in endurance athletes
high-intensity training with high CHO availability followed by a CHO restriction
at night and a low-intensity fasting training the next day has shown to have no
effect.
Training sessions with low CHO availability induce physiologic adaptations
compared with the same training session with a linear or high CHO availability.
Athletes can ingest large amounts of CHO (approximately 10 g kg−1 BW)
approximately 36 h before a competition to ensure muscle glycogen repletion.
Authors observed that periodizing CHO improved 10-km running and cycling
efficiency and increased time to exhaustion.
The time of CHO intake should be individualized and periodized according to the
level of the athletes’ training cycles.
Conclusion:
It is important for elite soccer players to ingest large amounts of CHO 36 hours
before the game to maximize glycogen stores by 1-1.5 g.
This can help energy last for up to 4 hours.
4. Kean, J, Shovlin, A, Devenney, S, Malone, S, Young, D, Coratella, G, Collins, K,
Shortall, M. The performance effect of scheduled carbohydrate and caffeine intake
during simulated team sport match-play. 1-13, 2020.Nutrients 12(7):
Introduction:
Hurling is a stick and ball intermittent field sport where the competitive play is
superimposed on bouts of high-speed running followed by active recovery.
High-speed word rate was shown to decrease throughout match play.
CHO (carbohydrate) ingestion has been shown to reduce the rate of glycogen
depletion and maintain blood glucose concentration.
CAF (caffeine) has shown to delay the onset of fatigue.
When combined, they both increase the work completed during a 120minute
cycling simulation by 23% compared to placebo and CHO only.
The timing and quantity of CHO and CAF during research studies has been
shown to vary.
The current carbohydrate intake recommendations the day before a game is 7 g
and further supplementation 1-4 g recommended 1-4 hours before competition.
Methods:
10 white, 22-year-old male sub-elite hurling players were the subjects.
Subjects were asked to refrain from alcohol, caffeine, and vigorous exercise for
48 hours prior to testing.
Subjects were instructed to do CHO loading for 48 hours prior to testing.
Subjects were instructed to intake 5-6 g of CHO and 1.7 g of protein for exercise
in less than 90p minutes in duration.
Measurements were recorded using a stadiometer and weighing scales.
V02 max testing was completed prior to match play stimulation.
During weeks 2-5, subjects completed three HSP with specific supplementation,
CHO, CHO+CAF, and placebo, and separated by a 5-day recovery period.
Trials were completed in randomized, double-blinded order and all trials were
completed at a similar time of the day.
Subjects did not receive the same supplement more than once.
Each subject completed a 10 min warm up and then HSP consisted of two 30 min
halves comprised of multiple movements (walk, back pedal, shuffle, cruise, and
sprint) also separated by a 10-minute half time.
12X20 maximal shuttles were completed by each subject at half time and full
time.
The mean sprint ability and best sprint ability was recorded.
VO2 max, RER and HR were recording.
CHO supplementation was administered at 15, 30 and 45 minutes.
Results:
Non-significant differences were observed between supplement trials.
Differences were reported across variables between time conditions.
There were significant differences between supplements CHO + CAF and PLA
trials.
Discussion:
The purpose of this study was to see the effects of scheduled CHO and CAF both
prior to and during stimulated hurling match play.
The data provides that the combined utilization of CHO + CAF may improve
repeated sprint ability within hurling cohorts.
VO2, RER and HR responses were not significantly affected in response to
nutritional interventions.
Combined CHO + CAF had a significant effect on sprint performance specifically
at full time, with a decrease in performance compared to only CHO and PLA.
5. Lee, C, Cheng, C, Lee, C, Kuo, Y, Chang, W. Co-ingestion of caffeine and
carbohydrate after meal does not improve performance at high-intensity intermittent
sprints with short recovery times. European Journal of Applied Physiology 114(7):
1533-1543, 2014.
Introduction:
Ingesting caffeine before exercise improves high intensity intermittent sport
performance with high recovery times but not with low recovery times.
CHO may improve intermittent high intensity exercise by reducing the use of
muscle glycogen.
Caffeine and carbohydrate co ingestion increases exogenous CHO oxidation.
Co ingestions produces positive effects on repeated sprinting performance/
This study will find out the effects of caffeine only and carbohydrate only to
address the potential for ingredient interactions on anaerobic capacity and
physiological responses during high intensity intermittent sprint test.
Hypothesis: ingesting CHO before exercise enhances performance and the
beginning of an exercise and ingesting caffeine does not benefit high intensity.
Methods:
12 athletes, age 20.
Each had team sport experience.
Subjects asked to do unstructured moderate to heavy exercise for at least 5 days
per week before experiment.
24 hours before, subjects were asked to refrain from heavy exercise.
Study was a double-blind, balanced trial.
Subjects came for 5 different trials over a span of 1 month.
Subjects followed the same diet during the 24 hours before each trial and asked to
avoid caffeine and alcohol intake.
Subjects arrived 2 hours before trial and at a prepacked breakfasted with 65%
carbs.
Subjects were then randomized for the trial either (CAF +PLA), (CAF+ CHO),
(PLA + CHO) or (PLA +PLA).
Subjects were performing HIS (High-intensity intermittent sprint) test.
Results:
No significant difference among trials PPO, MPO, or sprint.
Group data was biased among 3 of 12 participants who were identified as high
caffeine responders.
Discussion:
Purpose of this study was to examine the effects of caffeine and carbohydrate
supplementation on 10 sets of HIS with short recovery periods.
CAF + CHO and PLA + CHO trials, CHO increased blood glucose levels from
the pre-test to Set 5, then gradually decreased until the end of testing.
Blood glucose levels at the onset of exercise could be significantly increased by
ingesting the hypertonic CHO drink 15 min prior to exercise.
The carbohydrate loading strategy did not provide improvements in high-intensity
intermittent sprint performance.
The amount of carbohydrate ingested should be sufficient to maintain a high rate
of exogenous carbohydrate oxidation during exercise.
Caffeine provision did not improve performance for HIS with short recovery.
Ingestion of caffeine or carbohydrate alone did not improve PPO and MPO,
whereas co-ingestion of caffeine and carbohydrate resulted in significant
decreases in TW and an elevated FI during HIS testing compared with PLA +
PLA and CAF + PLA trials.
6. Marquet, LA, Brisswalter, J, Louis, J, Tiolloer, E, Burke, LM, Hawley, JA,
Hausswirth, C. Enhanced endurance performance by periodization of carbohydrate
intake: “Sleep Low” strategy. Medicine & Science in Sports and Exercise 48(4): 663-
672, 2016.
Introduction:
Exercise-induced increase in p53 phosphorylation is greater when subjects
perform high-intensity interval running in conditions of reduced CHO availability
This study determined the effects of a chronic (3 wk) train-high, SL intervention
in trained triathletes on selected metabolic and performance outcomes.
The periodization strategy integrated three diet–exercise manipulations within a
real-world training program: HIT with high-CHO availability aimed at
maximizing adaptation and performance.
CHO restriction (low-CHO availability) to prolong the signaling response after
exercise.
A prolonged, submaximal training session commenced with low-CHO availability
to promote lipid metabolism.
Methods:
Subjects were 21 endurance trained male athletes.
The study used a parallel group design, with the subject cohort being randomly
divided into two groups who undertook the same endurance training program for
three consecutive weeks
The timing of CHO intake differed between the groups.
One group manipulated CHO availability high-intensity workout with high-CHO
availability followed by a CHO restricted recovery plus an overnight fast; then a
prolonged submaximal workout the following morning commenced with low-
CHO availability.
The control group maintained regular CHO intake over the day and undertook
each training session with normal or high CHO availability.
Subjects commenced a 6-week training program split into 3 weeks.
HIT protocol has previously been reported to use ~50% of starting muscle
glycogen stores in well-trained subjects who commence the sessions with normal
glycogen levels.
Total daily CHO intake was similar for both SL and CON groups, but the intake
was different throughout the day.
Results:
There was a similar change in reported macronutrient intake between baseline
(usual dietary habits) and the training–diet intervention period (prescribed menus)
for each group
Mean CHO intake significantly increased in the intervention period compared
with the baseline.
Discussion:
10-km running performance was improved when athletes periodized their CHO
intake and slept and performed selected training sessions with low-CHO
availability.
BM and body fat mass were reduced in response to altering the timing of CHO
intake during the 3-wk training block.
The Periodization strategy also enhanced the capacity for high-intensity exercise
lasting 60–70 s in endurance-trained subjects.
7. Marquet, LA, Hausswirth, C, Odeline, M, Hawley, JA, Burke, LM, Tiollier, E,
Brisswalter, J. Periodization of carbohydrate intake: Short- term effect on
performance. 8(12): 1-13, 2016.Nutrients
Introduction:
CHO are the main substrates used by the brain and skeletal muscles during
exercise.
Glycogen is not only an energetic substrate but more of a regulator of metabolic
signaling response.
Low glycogen studies have failed to show improvements on performance.
periodized approach to CHO availability in the training program, where sessions
undertaken to promote adaptation are carefully integrated with others focused on
high quality performance outcomes.
Sleep low strategy- one such sequence of periodized CHO availability, which
allows athletes to perform high intensity training sessions supported by high CHO
availability while enhancing metabolic adaptation associated with low glycogen
availability
Methods:
Subjects were 11 endurance trained male cyclists, between the ages of 18-40.
Subjects trained 12 hours a week with 3 years of prior training.
First week subjects ate their usual diets and second week they followed a specific
nutritional guideline.
Subjects were randomly assigned between two groups while doing the same one-
week training program but following different nutritional guidelines.
CHO intake was similar between the two groups but periodized differently over
the day.
One group trained with high CHO, with an even spread of CHO intake throughout
the day
The intervention group trained with a CHO intake that was periodized throughout
various days.
3 sessions of testing, pre and post-tests.
Study was divided into two phases, first lasting two weeks and second lasting one
week.
CHO intake was 6 grams a day.
Three blood samples were collected.
Results:
There was no significant difference in the CHO intake between both groups
before and after training.
Discussion:
Purpose of this study was to investigate the effect of a short-term exposure to a
periodized “sleep-low” training strategy on metabolism and performance for
cyclists.
sequence involving “train high, sleep low, and train low” based on periodizing
CHO intake
Significant improvement in performance during cycling time trial after one week
of “sleep-low” strategy.
One hypothesis to explain the impact of the periodization of CHO intake on the
improvement of performance could reside in changes in resting muscle glycogen
concentration.
8. McMahon, G, Thornbury, A. Ingested of carbohydrate prior to and during maximal,
sprint interval cycling has no ergogenic effect: A randomized, double-blind, placebo
controlled, crossover study. 1-12, 2020.Nutrients 12(8).
Introduction:
It is documented that acute carbohydrate supplementation (CHO) can enhance
exercise performance.
CHO ingestion can help preserve blood glucose concentrations and increase the
rate of glucose oxidation in the later stages of exercise when the sugar storage in
the skeletal muscles and liver are gone.
High intensity running and shorter, high intensity exercises can be enhanced with
CHO compared to a placebo.
Exercise intensity and volume increases volume are the two primary components
in modulating increases in aerobic adaptations through high intensity interval
training.
It’s possible that the addition of exogenous CHO prior to or during sprint interval
exercises may allow an individual to exercise more intensely and complete more
work within a specified timeframe.
Recommendations have been made to suggest that CHO ingestion may have an
ergogenic effect on exercise durations lasting a minimum of 45-60 min.
Methods:
15 physically active males and females, ages 18-39, were subjects in this study.
All subjects took part in participating in club sports at their college.
Subjects trained 2-3 sessions of moderate-high intensity activity lasting 90 min
each per week along with 1-2 competitive matches per week.
All subjects were healthy, free from injury and not supplementing with any
ergogenic aids 3 months prior to or during the study.
This study used a double-blind-placebo-controlled, randomized, cross-over
design, with two conditions: carbohydrate supplementation and placebo.
Ten minutes prior to and during SIE, the subjects consumed either a carbohydrate
solution or a placebo.
Subjects were restrained from exercise 48 hours prior to their lab visit and to
abstain from alcohol and caffeine for 24 hours before testing.
Body mass was recorded on each of the 2 lab visits and subjects performed a 5-
minute warm up on a cycle ergometer.
Subjects performed four bouts of SIE, consisting of repeated maximal effort for
30 seconds at a standardized air resistance of level 6, followed by 3.5 min of
passive recovery following each interval. During recovery, subjects were allowed
to disembark the ergometer, but had to stay stationary.
Subjects ingested a carbohydrate solution consisting of 8% carbohydrate (100%
Maltodextrin, MyProtein, THG, Manchester, UK) and a single lemon-flavoured
sweetener tablet per litre water (Splenda, Heartland Food Products Group, PA,
USA), or a placebo consisting of water and a single lemon sweetener tablet per
litre.
Exactly 50% of the solution was consumed approximately ten minutes prior to the
first interval.
Results:
There were no significant condition times time interactions assessing for order of
effects in neither of the performance variables.
A paired t-test revealed body mass was not different between trails.
Discussion:
Purpose of this study was to determine whether ingestion of a carbohydrate
solution immediately prior to and during exercise would affect performance or
alter whole body physiological responses during SIE.
The present data suggests that acute CHO supplementation before and during
repeated 30 second maximal sprint interval exercise does not improve exercise
performance or alter physiological response compared with a placebo.
CHO ingestion immediately prior to and during short, maximal, and repeated
sprint exercise is not a key consideration in a performance context or to enhance
training quality.
9. Pomportes, L, Brisswalter, J, Hays, A, Davranche, K. Effect of carbohydrate intake on
maximal power output and cognitive performances. 4(4): 1-13, 2016.Sports
Introduction:
Gordon reported that ingestion of candy by runners during a marathon prevented
hypoglycemia and improved race times compared to no sugar.
The beneficial effects of CHO during exercise seem to affect the CNS by
increasing substrate delivery to the brain.
CHO may have a “non-metabolic” central effect.
The positive effect of CHO on performance has been observed during prolonged
exercise.
CHO mouth rinsing brings a positive effect through receptors in the mouth.
The current state of the art showed that CHO feedings could improve both
physical and cognitive performances; however, the effect of CHO
supplementation on cognitive functions has been essentially assessed during
endurance exercises.
This study aimed to investigate the effect of CHO supplementation on intermittent
sport performance, more particularly on sprint and cognitive performances, during
a protocol involving brief high-intermittent exercise in high-level athletes in
intermittent sports (e.g., squash and fencing).
Methods:
Subjects were 17 squash and fencing athletes.
Anthropometric and physiological characteristics were collected.
Heart rate and blood lactate concentrations were collected.
Each subject participated in 2 counterbalanced sessions separated by 1 week at the
same time of the day.
Subjects were asked to keep a food diary 2 day prior to the first session and to
replicate the diet before each session.
Asked to refrain from alcohol and, caffeine and drugs 48 hours prior to session.
Last meal was 3 hours before sessions
No food or drink was intake was allowed between the last meal and sessions
During session the subjects ingested 60 min and 30 min before exercise either 250
ML of CHO or a placebo.
Immediately after, subjects performed the first test.
After the warmup, subjects performed a repeated sprint test.
Results:
No significant difference between CHO vs placebo on peak power and tiredness.
Discussion:
This study aimed to investigate the effect of CHO ingestion on muscular and
cognitive performances using multiple sprints exercise with incomplete recovery.
Using a qualitative approach, CHO ingestion enhances sprint and cognitive
performances.
CHO increased maximal power output and reduced muscular tiredness compared
to the placebo.
Positive effect is mainly observed after or during aerobic exercise with a
minimum duration of 20-60 min.
10. Riis, S, Moller, AB, Dollerup, O, Hoffner, L, Jessen, N, Madsen, K. Acute and
sustained effects of a periodized carbohydrate intake using the sleep-low model in
endurance-trained males. Scandinavian Journal of Medicine & Science in Sports
29(12): 1866-1880, 2018.
Introduction:
Human CHO stores represent a limited decrease utilization of glycogen which
then will be available when a more intense work is demanded.
Sleep-low model- A high intensity interval session is performed in the evening ‐
combined with a continuous exercise session at moderate intensity the following
morning with restriction of CHO intake between sessions.
Training with low endogenous and exogenous CHO availability induced by
intense exercise and CHO restriction during recovery optimizes peripheral
training
The sleep low model increases whole body fat oxidation acutely during the ‐ ‐
continuous exercise session.
The purpose of this study was to investigate the effect of twelve repetitions of the
sleep low model over 4‐ weeks on sustained changes in whole body fat ‐
oxidation rate, endurance performance, and expression of LD associated proteins ‐
in endurance trained cyclists‐
This study hypothesized that the sleep-low model would introduce higher whole
body fat oxidation rate in an acute trial compared to high CHO availability.
Methods:
Subjects were 18 endurance trained males, between the ages of 18-45.
This study added a cross-sectional analysis to the present study.
Subjects went through a trial of tests before the study was conducted.
Subjects were paired based on their VO2 max, MFO, and estimated habitual
training volume.
Subjects were randomized into two groups.
First group was the sleep-low model and other group was high CHO availability.
All subjects did the same training program but timing of CHO intake on training
days were different.
Study was 3 training blocks per week for 4 weeks.
Each having HIT in the evening and CON the following morning.
HR for each subject was detected.
Dietary intake was controlled around each training block from 2 hours prior to
HIT until water.
Before sleep subjects ingested 20 grams of PRO, 1.3 grams of CHO, and 2.1
grams of FAT.
To determine the difference between groups each subject recorded their food and
fluid intake for 4 days before the intervention.
To evaluate the effect of the sleep-low model on fat, each subject performed a 60-
minute CON session.
Timing of CHO intake was different between the groups during the intervention.
First, subjects rested in supine position for 20 minutes and got their blood drawn.
Then HIGH CHO consumed their CHO rich meal, while participants in LOW‐ ‐ ‐
CHO remained fasted. 30 minutes after the meal, another blood sample was
drawn prior to exercise.
The first 16 minutes of the 60 minute exercise session‐ consisted of 4 minutes at
30%, 40%, 50%, and 60% of PPO, respectively, to estimate MFO and Fatmax
during low to moderate exercise‐ ‐
Plasma was measured after interventions.
Results:
No change in whole body fat oxidation after sleep-low intervention.
Endurance performance improved for both groups.
No changes in proteins involved in skeletal muscles.
Sleep-low model increases who body fat rate during acute exercise.
Discussion:
LOW CHO had higher whole body fat oxidation rate‐ ‐ ‐ during CON than HIGH
CHO in the accustomed state due to different timing of the CHO intake.
Data suggest that elevated plasma glucose and corresponding insulin response to
the CHO rich meal lowered whole body fat oxidation rates in HIGH CHO.‐ ‐ ‐
If slowly absorbed CHO is ingested 30 minutes prior to exercise, the combination
of hyperinsulinemia and decreased fat oxidation rates is not observed when
compared to glucose ingestion.
Repeating the sleep low model did not translate into sustained improvement of fat‐
oxidative rate during exercise in the fed state.
Timing of carbohydrate intake before a race.
Independent variable: The timing of the intake of carbohydrates. Set different times for athletes
to take in carbohydrates before their race.
Dependent variable: The race. Measure their blood sugar after race.
Hypothesis: Periodization of CHO can help athletes perform better to ensure muscle glycogen
supercompensation. If high-intensity athletes’ intake 1g of CHO per body weight a day, 30
minutes before a race, then athletes will perform better with high energy.
