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Nutrition to Support Recovery from Endurance Exercise: Optimal Carbohydrate and Protein Replacement


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Proper nutrition is vital to optimize recovery after endurance exercise. Dietary carbohydrate and protein provide the requisite substrates to enhance glycogen resynthesis and remodel skeletal muscle proteins, respectively, both of which would be important to rapidly restore muscle function and performance. With short recovery windows (<8 h), coingestion of these macronutrients immediately after exercise can synergistically enhance glycogen resynthesis and rapidly stimulate muscle protein synthesis (MPS), the latter of which is augmented by protein ingestion alone. Consuming frequent meals throughout the day containing adequate carbohydrate (according to training intensity) and protein (approximately 0.25 g·kg) will help fully restore muscle glycogen and sustain maximal daily rates of MPS over prolonged (8 to 24 h) recovery periods. Given the complementarity of these macronutrients, endurance athletes aiming to maximize postexercise recovery to maintain or enhance subsequent exercise performance should target a nutrition strategy that features optimal ingestion of both carbohydrate and protein.
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Nutrition to Support Recovery from Endurance
Exercise: Optimal Carbohydrate and
Protein Replacement
Daniel R. Moore, PhD
Proper nutrition is vital to optimize recovery after endurance exercise.
Dietary carbohydrate and protein provide the requisite substrates to en-
hance glycogen resynthesis and remodel skeletal muscle proteins, re-
spectively, both of which would be important to rapidly restore muscle
function and performance. With short recovery windows (G8 h),
coingestion of these macronutrients immediately after exercise can
synergistically enhance glycogen resynthesis and rapidly stimulate
muscle protein synthesis (MPS), the latter of which is augmented by
protein ingestion alone. Consuming frequent meals throughout the day
containing adequate carbohydrate (according to training intensity) and
protein (approximately 0.25 gIkg
) will help fully restore muscle gly-
cogen and sustain maximal daily rates of MPS over prolonged (8 to 24 h)
recovery periods. Given the complementarity of these macronutrients,
endurance athletes aiming to maximize postexercise recovery to main-
tain or enhance subsequent exercise performance should target a nutri-
tion strategy that features optimal ingestion of both carbohydrate and
Endurance exercise is classically associated with relatively
long-duration, constant-load exercise that is characterized
by large increases in oxygen consumption, although repeated
shorter-duration, higher-intensity exercise bouts also rely
heavily on aerobic energy systems for optimal performance
(6). These endurance-type exercises can be stressful events
for the human body and can be accompanied by depletion of
endogenous energy stores (e.g., muscle and liver glycogen)
variety of different body proteins (e.g., skeletal muscle, bone,
cardiovascular system, etc.). For example, exercise performed
at intensities greater than approximately
50% to 60% of peak aerobic fitness,
such as constant-load running or cycling,
or that which requires supramaximal
intensities (especially when repeated),
such as team sport exercises like soccer
or ice hockey, rely primarily on carbo-
hydrate as energy source (40,45). In ad-
dition, these exercise modalities represent
potent stimuli for metabolic (e.g., mito-
chondrial biogenesis, metabolic enzyme
upregulation) (9) and structural (e.g.,
contractile protein repair and synthesis)
skeletal muscle adaptations (16) that,
through the remodeling of muscle and
body proteins, can ultimately translate
into performance adaptations such as
increased aerobic/anaerobic power pro-
duction (9). In light of these acute
stresses, the athlete who optimally re-
covers from an acute bout of exercise is better positioned to
maintain or enhance their performance during a subsequent
bout and/or to adapt, over time, to the repeated stress of
multiple exercise bouts (i.e., training).
Proper nutrition is vital to optimize postexercise recovery.
Dietary carbohydrate and protein are important macronu-
trients for the endurance athlete, as they provide the requisite
substrates to enhance glycogen resynthesis and muscle re-
modeling. While other aspects of recovery such as fluid resto-
ration and/or maintenance of immune function are important
considerations for the endurance athlete and have been re-
ported to be influenced by these macronutrients as well, the
focus of the present review will be on the role carbohydrate
and protein have on the ability to enhance recovery primarily
within skeletal muscle. Highly active endurance athletes may
have recovery widows that range from relatively short (e.g.,
two-a-day training, tournament play) to longer (e.g., daily
training bouts) intersession recovery periods depending on
their training phase or competition schedule. Therefore, this
review will summarize the current literature on the specific
carbohydrate and protein ingestion strategies to support gly-
cogen resynthesis and skeletal muscle remodeling over shorter
294 Volume 14 &Number 4 &July/August 2015 Carbohydrate and Protein for Endurance Athletes
Faculty of Kinesiology and Physical Education, University of Toronto ,
Toronto, Ontario, Canada
Address for correspondence: Daniel R. Moore, PhD, Faculty of Kinesiology
and Physical Education, University of Toronto, Goldring Centre for High
Performance Sport, 100 Devonshire Place, Toronto, Ontario, Canada M5S
2C9; E-mail:
Current Sports Medicine Reports
Copyright *2015 by the American College of Sports Medicine
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
(i.e., G8h)andlonger(i.e.,8to24h)recoveryperiods.
Moreover, focus will be placed on highlighting the synergies
between optimal carbohydrate and protein replacement to
provide practical nutrition guidelines for a comprehensive re-
covery strategy for the endurance athlete.
Endurance exercise that is sustained at a moderate to high
intensity and repeated supramaximal efforts primarily rely
on carbohydrate as a source of fuel (40,45). In the face of
enhanced glucose uptake by working muscles, blood glu-
cose levels are maintained to a large extent by the break-
down of liver glycogen stores. Despite this enhanced liver
glycogenolysis, muscle glycogen is the most immediate en-
ergy supply during these higher-intensity endurance-type
exercises due to the proximity of specific intramuscular
pools to the mitochondria, sarcoplasmic reticulum, and/or
or the contractile myofibrillar proteins, where instanta-
neous energy requirements are highest during muscle con-
traction (36). Bergstro
¨m et al. (4) were the first to discover
that fatigue during prolonged exercise was associated with
muscle glycogen depletion. Subsequent research has ex-
panded on this seminal study to elucidate the subcellular
localization of intramuscular glycogen and the subsequent
regional intracellular and/or fiber type-specific depletion of
these energy stores with muscle fatigue (31,36). In light of
the importance of this intramuscular energy store for exer-
cise performance and the early work showing it can be
influenced by diet (4,14), considerable attention has been
placed on elucidating the optimal dietary strategies to re-
store, maintain, and/or enhance muscle glycogen for the
goal of maximizing exercise performance.
It is well-known that athletes competing maximally during
high-intensity endurance exercise must ensure that their car-
bohydrate stores are optimized before and during exercise to
perform at their best (10). Managing precompetition carbo-
hydrate intake and strategies to supercompensate glycogen
stores (i.e., glycogen loading) prior to competition are im-
portant considerations for endurance athletes. In addition,
carbohydrate intake during exercise, either for a source of
fuel for events 990 min and/or for ‘‘mental’’ energy (e.g.,
carbohydrate mouth rinse), are useful dietary strategies to
successfully enhance endurance exercise performance (22).
While these aspects of carbohydrate ingestion would be im-
portant considerations for optimal endurance exercise per-
formance, they are not within the remit of the present review
focused on postexercise recovery, and therefore, interested
readers are referred to additional reviews and/or consensus
statements that cover these aspects of sports nutrition in
more detail (e.g., (10,22)).
Contemporary research suggests that training with low
carbohydrate availability could represent a strategy to en-
hance training-induced adaptations (e.g., mitochondrial bio-
genesis, enhanced fat oxidation) that may subsequently
improve endurance exercise performance (for review, see
(36)). These strategies may include fasted (e.g., prebreakfast)
or glycogen-depleted (e.g., two-a-day training with low in-
tersession carbohydrate intake) training and/or carbohydrate
restriction during recovery (2). Progressive sports practi-
tioners and athletes have begun experimenting with these
different forms of low carbohydrate availability training to
enhance aerobic adaptations during early base training stages
(42). As such, these athletes may deliberately restrict carbo-
hydrate intake during the postexercise recovery period to
minimize glycogen resynthesis. While this emerging area of
research is intriguing, the focus of the present review will be
to summarize the nutritional requirements for athletes
aiming to maximize glycogen resynthesis after exercise in
order to maintain performance or training quality in subse-
quent bouts of exercise. Moreover, although some supple-
ments (e.g., caffeine, creatine) have been reported to enhance
rates of glycogen resynthesis, the present review will limit the
discussion to the impact carbohydrate and protein have in
replenishing endogenous fuel stores.
Carbohydrate for Short-Term Recovery (G8h)
Carbohydrate intake is crucial to enhance muscle and
liver glycogen stores after high-intensity, carbohydrate-
based exercise. The rate of muscle glycogen resynthesis is
generally greatest during the initial È1 h after exercise and
is facilitated by the contraction-induced recruitment of
GLUT-4 transporters to the muscle membrane and an en-
hanced activity of the rate-controlling enzyme glycogen
synthase (21). For example, providing carbohydrate inges-
tion immediately after exercise resulted in an approximately
45% greater rate of glycogen resynthesis over the following
2 h as compared with delaying the ingestion by 2 h, which
ultimately translated into a greater net glycogen synthesis
over a 4-h postexercise recovery period (20). However, im-
mediate postexercise carbohydrate ingestion does not con-
fer any advantage toward net glycogen synthesis over longer
periods of recovery as immediate and delayed (i.e., 2 h) in-
gestion of carbohydrate result in equivalent muscle glyco-
gen concentrations 8 h after recovery (32). Therefore,
athletes who must maximize glycogen resynthesis for a
subsequent exercise bout less than 8 h should target a nu-
tritional strategy that initiates carbohydrate intake as
quickly as possible after exercise.
The rate of carbohydrate ingestion is also an important
determinant of how rapidly muscle glycogen is resynthesized.
Although few studies have directly assessed the relative dose-
response of carbohydrate ingestion on glycogen resynthesis, a
comprehensive review by Jentjens and Jeukendrup (21)
compared the rate of glycogen resynthesis relative to the
carbohydrate intake across multiple studies. These authors
(21) concluded that the maximal rate of glycogen resynthesis
(approximately 0.3 gImin
) during the early acute recovery
period (i.e., up to 8 h after exercise) appeared to occur with a
relative carbohydrate intake of 1.0 to 1.2 gIkg
(Fig. 1).
There was some evidence that protocols employing a feeding
pattern of small carbohydrate boluses every 15 to 60 min
elicited greater rates of glycogen synthesis than those with
intervals at approximately 2 h (e.g., (20,46)). However, it
was concluded that the limited research directly comparing
feeding patterns on maximal rates of glycogen resynthesis
precluded the recommendation toward an optimal ingestion
pattern, provided that target carbohydrate intake levels are
reached (21).
Dietary protein has no appreciable role in gluconeogenesis
(18) and therefore when ingested alone would not serve as a
substrate for glycogen resynthesis during recovery from high-
intensity endurance-type exercise. However, as summarized Current Sports Medicine Reports 295
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
by Betts and Williams (5), the addition of protein to a car-
bohydrate beverage can increase rates of glycogen resynthesis
when carbohydrate intake is below optimal levels (i.e., G1
) (Fig. 1). This enhanced glycogen resynthesis has
generally been attributed to the insulinogenic effect of pro-
tein and certain amino acids (e.g., leucine and phenylala-
nine), which helps drive glucose into the muscle when
carbohydrate intake rates are submaximal (46). Although
athletes can practically augment rates of muscle glycogen by
consuming a protein/carbohydrate blend, the effect of this
nutritional approach on subsequent exercise performance,
especially with submaximal rates of glycogen resynthesis
through suboptimal rates of carbohydrate delivery, is equiv-
ocal (27). Nevertheless, given the additional benefits of con-
suming protein immediately after exercise to support the
repair and remodeling of skeletal muscle (see below), en-
durance athletes should consider including this macronutri-
ent in their recovery nutrition.
Carbohydrate for Long-Term Recovery (8 to 24 h)
The nutritional strategies outlined previously (e.g., car-
bohydrate timing and pattern) that are employed to maxi-
mize muscle glycogen resynthesis during short-term (i.e.,
G8 h) recovery are generally not as important when longer
periods of recovery are possible between successive exercise
bouts. For example, the timing of carbohydrate intake rel-
ative to exercise (i.e., immediate vs delayed by 2 h) has little
bearing on the rate of glycogen resynthesis over 8 and 24 h
of postexercise recovery (32). Moreover, consuming a
carbohydrate-rich diet (i.e., approximately 12 gIkg
as two large meals as compared with seven smaller meals
results in similar net muscle glycogen synthesis over 24 h
(14). Given that muscle glycogen gradually declines over
3 d of successive high-volume exercise (i.e., approximately
16-km runs) despite consuming a moderately high-
carbohydrate diet (estimated from average energy intake,
percent carbohydrate, and average body weight at approx-
imately 5 to 7 gIkg
) (13), it is generally accepted that
consuming adequate daily carbohydrate (independent of its
pattern and/or timing) is the most important nutritional
strategy to maximize muscle glycogen resynthesis with pro-
longed (i.e., 98 h) postexercise recovery (10,21). Therefore,
athletes aiming to maximize glycogen resynthesis and en-
dogenous carbohydrate stores are recommended to consume
carbohydrate relative to their body weight (and not as a
percentage of total energy) and training load (10), which in
the case of the previous study with suboptimal glycogen re-
pletion over 3 d of high-volume training (13) may have been
as high as 10 gIkg
. Additional guidelines are briefly
summarized in the Table but can be consulted in their en-
tirety in the International Olympic Committee Consensus
Conference on Nutrition for Sport review (10).
Amino acids represent a relatively minor energy substrate
during normal exercise (approximately 2% to 5% of total
adenosine triphosphate production), but their absolute ox-
idation can be increased several-fold with the increased
energy demands of endurance-type exercise; this oxidation
represents a net loss of amino acids from the free pool
within muscle. In addition, endurance exercise is a major
stimulus to remodel skeletal muscle, which results in the
breaking down of old and/or damaged muscle proteins
(muscle protein breakdown (MPB)) and the (re)building of
new ones (muscle protein synthesis (MPS)) in their place.
This enhanced protein ‘‘turnover’’ functions to remodel the
major muscle protein fractions such as the energy-
producing mitochondria and the force-generating myofi-
brillar proteins (16,48) and is primarily regulated by
changes in MPS (8). Ultimately, this increased oxidation of
amino acids and extensive remodeling of body and muscle
proteins translate into a greater daily protein requirement
(i.e., 1.2 to 1.7 gIkg
) for individuals engaged in
chronic endurance exercise (i.e., training) than the general
population (44). Provided that energy intake meets the in-
creased energy demands of this active population, endurance
athletes generally meet their minimum protein requirements
(44). However, contemporary research is revealing that it is
not just ‘‘how much’’ protein an active individual consumes
during the day but more importantly ‘‘when’’ and in ‘‘what
pattern’’ they consume it in that is important to maximize
MPS during recovery from exercise and, potentially, training-
induced muscle remodeling (as discussed in the following
section). While much of the research to date has centered on
protein after resistance exercise, these nutritional tenets of
maximizing MPS are arguably transferable to endurance-
exercise modalities as well (28).
Short-Term Recovery (G8h)
The most important nutritional factor for enhancing
postexercise MPS is the ingestion of dietary protein (24)
(Fig. 2), which provides the requisite amino acid building
blocks for repairing, remodeling, and/or building new
muscle. For example, carbohydrate ingestion alone has no
effect on MPS (24) and does not augment the dietary amino
Figure 1: Schematic representation of the independent and
combined effects of the rate of carbohydrate and/or protein inges-
tion on the relative rate of muscle glycogen resynthesis over short-
term (i.e., G8 h) recovery after endurance exercise. Carbohydrate is
adapted from (5), with maximal glycogen resynthesis occurring at
1.0 to 1.2 gIkg
. Carbohydrate/protein represents an esti-
mated 3:1 ratio of each macronutrient and is estimated to enhance
glycogen synthesis rates when suboptimal carbohydrate is
ingested, as per (5). Protein is predicted to have no effect on gly-
cogen resynthesis given that dietary protein is not a major source of
gluconeogenic substrates (18). CHO, carbohydrate; PRO, protein.
296 Volume 14 &Number 4 &July/August 2015 Carbohydrate and Protein for Enduran ce Athletes
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
acid-induced stimulation of MPS after exercise (23,41).
While carbohydrate (and primarily the associated insulin
response) can suppress MPB after exercise, this effect is
observed with as little as a 30-g bolus of the macronutrient
and has a relatively minor role (as compared with amino
acid-induced stimulation of MPS) in determining the net
muscle protein balance (i.e., the algebraic difference be-
tween MPS and MPB) during recovery from exercise (19).
Therefore, endurance athletes who prioritize carbohydrate
intake for enhanced rates of glycogen resynthesis will un-
doubtedly elicit an insulin response that is sufficient to
maximally attenuated MPB.
Previous studies have demonstrated that a single 20-g
bolus of high quality protein (i.e., egg or whey) is sufficient
to maximize MPS after resistance exercise with greater
protein amounts, resulting in increased amino acid oxida-
tion (i.e., the utilization of dietary amino acids as a source of
fuel) (30,49). While no similar dose-response studies exist
after endurance exercise, it has been shown that 16 g of milk
protein (25) and 20 g of whey protein (7) augment
postexercise rates of MPS after aerobic-based exercise.
Therefore, it is likely that a similar ingested dose should be
targeted for endurance athletes aiming to enhance MPS af-
ter exercise. From a more personalized approach, the ab-
solute 20-g dose utilized in previous studies (30,49) would
be equivalent to approximately 0.25 gIkg
(based on av-
erage study body weights) of high-quality protein (see the
following section for additional discussion and Fig. 2),
which is a similar relative protein dose that has recently
been reported to maximize MPS at rest in young adults (29).
The timing of the protein ingestion also may be an impor-
tant factor to initiate the recovery process after a bout of
endurance exercise. Consuming a source of protein immedi-
ately after endurance exercise is critical to enhance MPS, as
delaying this ingestion by as little as 3 h has been shown to
markedly attenuate the anabolic effects of the dietary amino
Figure 2: Schematic representation of the independent and
combined effects of a single meal ingestion of carbohydrate and/or
protein on MPS after endurance exercise. Carbohydrate would be
predicted to generally have no effect on MPS after exercise (23,41).
Protein would induce a dose-dependent stimulation of MPS up to a
plateau of 20 g or 0.25 to 0.3 gIkg
(29,30). Carbohydrate/protein
represents a 3:1 ratio of each macronutrient and would be esti-
mated to induce a linear dose-response up to 0.7 gIkg
(or the
equivalent of approximately 0.23 g proteinIkg
). CHO, carbohy-
drate; PRO, protein.
General carbohydrate and protein guidelines for glycogen resynthesis and muscle protein remodeling for endurance athletes.
Recovery Period
Glycogen Resynthesis Muscle Protein Remodeling
CHO Protein
G8 h Immediate postexercise
When CHO
G1.2 gIkg
30 g per meal
(suppress MPB)
Immediate postexercise ingestion
1.2 gIkg
20 g per meal (approximately
0.25 to 0.3 gIkg
High glycemic index Meal every 3 to 4 h
Multiple CHO sources Leucine enriched
Rapid digestion
8 to 24 h Moderate training,
N/A N/A 20 g per meal (approximately
0.25 to 0.3 gIkg
High training,
Meal every 3 to 4 h
Very high training,
10 to 12 gIkg
Pre-bedtime ingestion
1.2 to 1.7 gIkg
Muscle protein remodeling: protein intake stimulates the prime-regulated variable of MPS, whereas carbohydrate has a mild suppressive effect
on MPB.
Carbohydrate intake over 8- to 24-h recovery adapted from Burke et al. (10) and represents daily targets: moderate training, approximately
; high training, 1 to 3 hId
; very high training, 4 to 5 hId
. Carbohydrate guidelines are generally related to exercises that rely primarily on
carbohydrate as a fuel, such as repeated high-intensity interval exercise and/or constant workload at Q65% maximal aerobic capacity.
Protein coingestion may be as low as approximately 20 g (10).
CHO, carbohydrate; N/A, not a major consideration. Current Sports Medicine Reports 297
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
acids (24). This enhanced MPS would be consistent with a
greater remodeling and/or repair of skeletal muscle and
subsequently maximizing this process as quickly as possible
after a bout of exercise would intuitively facilitate a more
rapid recovery for the endurance athlete. A recent systematic
review suggests that postexercise protein intake has little ef-
fect on exercise performance in a subsequent single bout up
to 24 h after the first (27), which may suggest that the acute
enhancement of MPS does not directly enhance acute re-
covery. However, additional research is required to elucidate
the potential benefits of postexercise protein ingestion on
adaptations to endurance-training (i.e., recovery from mul-
tiple exercise bouts), as a subsequent systematic review from
the same group suggested that protein supplementation,
which would presumably stimulate MPS during recovery,
may enhance aerobic/anaerobic power adaptations in ath-
letes (34). Nevertheless, in the absence of any ostensible
ergolytic effects, the postexercise ingestion of dietary protein
to augment rates of MPS (7,24,25), should be viewed as an
important nutritional strategy for the endurance athlete to
support muscle remodeling and recovery.
Dietary proteins are not all created equal and can differ in
both their amino acid composition and digestion rate (i.e.,
how quickly their constituent amino acids appear within the
circulation). For example, despite all being similarly high-
quality proteins according to the protein digestibility
corrected amino acid score (1.0), whey protein generally
elicits a more robust stimulation of MPS than both soy and
micellar casein at rest and after resistance exercise (43). The
greater anabolic effect of whey protein is generally attrib-
uted to its naturally high leucine content (an essential amino
acid that is an important initiator of MPS (17) and its rapid
digestion (47), which has led to the suggestion that a
postexercise protein source should carry these attributes to
maximize MPS (35). However, vegetable-based proteins
(43), protein blends (37), and whole foods (12) also can be
sufficiently high-quality protein sources that induce a
postexercise amino acid profile that would likely support
enhanced rates of MPS after exercise. It may be worth
noting that a potentially slightly greater protein intake may
be required to achieve a similar postexercise MPS response
given the relatively lower leucine content of these protein
sources (37). Therefore, in light of the previously deter-
mined ingested protein dose-response with high-quality egg
or whey protein, athletes who prefer alternative protein
sources may wish to consider a slightly greater (e.g., ap-
proximately 25%) intake to enhance their anabolic effects.
Long-Term Recovery (8 to 24 h)
A single bout of high-intensity endurance exercise has
been reported to increase the remodeling of skeletal muscle
for up to 24 h, as evidenced by the stimulation of force-
generating myofibrillar and mitochondrial protein synthesis
during this prolonged recovery period (16). As such, maxi-
mizing MPS during this period with proper nutrition could
be viewed as a key strategy to support optimal recovery and
skeletal muscle remodeling for the endurance athlete. It has
recently been demonstrated that the daytime pattern, and
not just the absolute amount, of protein intake can influence
the elevation of MPS after an acute bout of resistance exer-
cise. For example, the repeated ingestion of 20 g of protein
every 3 h (i.e., 80 g in total) was shown to support greater
rates of myofibrillar protein synthesis over 12 h after resis-
tance exercise as an identical amount ingested as either eight
feedings of 10 g every 1.5 h or two feedings of 40 g every 6 h
(1). Therefore, given that dietary protein acutely augments
postexercise rates of MPS after a bout of endurance exercise
(7,24), athletes aiming to optimize their recovery with this
training modality would likely also benefit from the inges-
tion of 20 g (or approximately 0.25 gIkg
, see previous
section) protein every 3 to 4 h to sustain maximal rates of
MPS. This meal feeding frequency (i.e., four to six meals per
day) would be consistent with current practice in elite ath-
letes (11) and also could represent a strategy to help achieve
their relatively high target daily carbohydrate intake levels
(see previous section and Table).
Aside from optimal feeding strategies during daytime
waking hours, it has been demonstrated that the postexercise
increase in MPS with dietary protein ingestion does not ex-
tend into the overnight recovery period (3). This is likely due
to a lack of circulating plasma amino acids, which generally
return to fasted levels within approximately 3 to 4 h after
protein-containing meal consumption (12), to support max-
imal rates of MPS. However, it has recently been demon-
strated that pre-bedtime protein ingestion represents a
practical means to sustain circulating amino acids and sup-
port MPS during an 8-h sleep period after a bout of resistance
exercise (38) and to enhance training-induced increases in
muscle mass and strength (39). Therefore, as proper sleep is
vital to support overall health and optimal recovery in ath-
letes, pre-bedtime protein ingestion represents an additional
feeding opportunity during the recovery from endurance ex-
ercise to support enhanced rates of skeletal muscle remodeling.
Practical Recommendations
As outlined previously, endurance athletes have unique
nutritional requirements for both carbohydrate and protein
during recovery to facilitate the restoration of endogenous
fuel stores (i.e., glycogen) and to support the repair and re-
modeling of skeletal muscle, respectively. Generally, distinct
recommendations are made for either glycogen resynthesis
(e.g., (10)) or muscle remodeling independently (e.g., (35)).
However there are arguably complementary features of car-
bohydrate and protein replacement strategies that can be
leveraged toward a more holistic nutritional strategy for ef-
fective postexercise recovery (Fig. 1). The purpose of the
following section will be to provide a brief guide for some
practical strategies to enhance overall muscle recovery after
endurance exercise.
Athletes who have limited time between exercise bouts
(e.g., G8 h) and who are aiming to perform at their highest
level in each bout of exercise should consume protein and
CHO immediately after the first bout of exercise to initiate
the recovery process (20,24). The restoration of muscle gly-
cogen would be the relatively more important variable to
maintain exercise performance or training quality in the
subsequent exercise bout, although supporting skeletal mus-
cle remodeling (i.e., MPS) during this early recovery window
should be an important aspect of a multifaceted nutritional
recovery strategy, especially in the context of a longer-term
training program (33,34). As such, athletes should target
approximately 0.25 gIkg
of high-quality protein (e.g.,
298 Volume 14 &Number 4 &July/August 2015 Carbohydrate and Protein for Enduran ce Athletes
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
leucine-enriched, rapidly digested sources such as whey) to
stimulate MPS combined with at least 0.75 gIkg
of car-
bohydrate, the latter of which will enhance glycogen
resynthesis and would far exceed the minimum dose that is
sufficient to suppress MPB (19). Athletes who can consume
greater carbohydrate will ensure glycogen synthetic rates are
maximized; however, if this high intake is not practical or
feasible, then protein coingestion will augment glycogen
synthesis below maximal carbohydrate ingestion rates of 1.0
to 1.2 gIkg
. It may be most practical to consume sports
nutrition products (e.g., recovery drinks, bars, gels, etc.) dur-
ing this first postexercise meal, as they are generally conve-
nient sources of multiple simple carbohydrates (e.g., glucose,
fructose, sucrose), which would provide ready substrates to
replenish both liver (e.g., fructose) (15) and muscle (e.g., glu-
cose) (21) glycogen. Additionally, nutrition in beverage form
would not only help with postexercise fluid replacement but
also enhance the rate of amino acid appearance (12), which
would help facilitate greater rates of MPS (47). Outside this
immediate postexercise recovery window, athletes should aim
to consume carbohydrate-rich foods at a similar rate as above
at least every 2 h (as practically possible) with the coingestion
of approximately 0.25 gIkg
of dietary protein; this target
protein intake may need to be increased slightly to maximize
MPSiflowerqualityproteins(e.g., plant based and/or blends
thereof) are ingested (37,43). While currently lacking direct
empirical evidence to support its efficacy over short-term re-
covery, adhering to these guidelines to maximize glycogen
resynthesis and support MPS (in addition to other aspects of
recovery such as rehydration) would ultimately position an
athlete in the best possible condition to maintain and/or en-
hance their exercise capacity and performance within an ab-
breviated recovery window.
Athletes who have the luxury of a longer intersession re-
covery window (i.e.,8to24h)maynotneedtobeasag-
gressive with their muscle glycogen recovery strategy, as
timing and pattern of carbohydrate intake have little impact
on the restoration of this endogenous energy store beyond
the early (i.e., 8 h) recovery period (14,32). Nevertheless,
consuming a source of carbohydrate immediately after exer-
cise could be considered a universal tenet regardless of the
available window of recovery, as this would help initiate
muscle glycogen resynthesis early in recovery. Moreover, this
early recovery nutrition, which as discussed could be practi-
cally supported by convenient sports nutrition products (al-
though this is not a requirement with a longer recovery
window), should contain approximately 0.25 gIkg
of pro-
tein to support skeletal muscle repair and/or remodeling
through enhanced rates of MPS. After this initial feeding, ath-
letes should consume adequate carbohydrate intake through
natural, carbohydrate-rich food sources to support their ha-
bitual training loads (Table). Frequent meal feedings (i.e.,
5 to 6 meals over a 12- to 15-h wake period) would be similar
to that of many elite athletes (11) and represent a practical,
convenient means to meet their high daily carbohydrate and
elicit an insulin response that would sufficiently attenuate
any exercise-induced increase in MPB (19). More impor-
tantly, each of these meals should contain adequate protein
(approximately 0.25 gIkg
depending on protein quality, see
previous section) including a pre-bedtime snack to sustain
maximal rates of daily MPS (1,38) and to obtain their in-
creased daily protein requirements (i.e.,1.2to1.7gIkg
Additionally, it could be argued that this meal frequency and
protein intake pattern that is aimed at maximizing MPS (and
presumably muscle repair) may be most critical after particu-
larly intense training bouts (e.g., supramaximal training, long
duration, and/or with large muscle-lengthening component,
such as downhill running), as muscle damage reduces endur-
ance exercise performance (26) and has been reported to in-
terfere with the ability to replenish glycogen stores during
long-duration recovery (50). Therefore, athletes who practice
these nutritional strategies over a more prolonged recovery
period would ultimately maximize their chances of main-
taining exercise performance in subsequent exercise bouts. In
the context of a high-intensity training program that stimu-
lates significant aerobic adaptations (9) that are ultimately
underpinned by changes in MPS (28), nutrition to support
optimal recovery to sustain a high work output during
repeated exercise bouts may ultimately enhance training-
induced adaptations. This optimized training nutrition rep-
resents a potentially fruitful area of future study for the
endurance athlete.
The resynthesis of muscle glycogen and the repair and/or
remodeling of muscle protein are highly influenced by the nu-
tritional environment and are of paramount importance for
optimal postexercise recovery after endurance exercise. As
such, a multidimensional nutritional strategy targeting the
combined ingestion of dietary carbohydrates and protein
(rather than either one alone) will be most effective in achiev-
ing these recovery goals. Ultimately, the athlete who optimizes
postexercise nutrition after an acute bout of exercise will be
best positioned to maintain or enhance performance during a
subsequent bout and/or to adapt, over time, to the repeated
stress of multiple exercise bouts (i.e., training).
The author declares no conflict of interest and does not have any fi-
nancial disclosures.
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300 Volume 14 &Number 4 &July/August 2015 Carbohydrate and Protein for Enduran ce Athletes
Copyright © 2015 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
... Healthy diet habits are also vital to restore energy. According to Moore (2015), carbohydrates and protein are essential macronutrients to provide substrates to enhance glycogen resynthesis and repair the skeletal muscle (Moore 2015). ...
... Healthy diet habits are also vital to restore energy. According to Moore (2015), carbohydrates and protein are essential macronutrients to provide substrates to enhance glycogen resynthesis and repair the skeletal muscle (Moore 2015). ...
... Healthy diet provide the substrates to enhance glycogen resynthesis, remodel skeletal muscle (Moore 2015) and increase functional capacity (Alghannam et al. 2018). ...
Objective: This systematic review aims to analyse physical fatigue and the main causes. Background: Fatigue results from physical and psychological overload, mainly due to daily stress and lack of time to recover energy. Method: The review was performed according to the Prisma Statement. It was accessed Scopus, Web of Science, Science Direct, Pubmed. 26 keywords were screened using Boolean operators. The first articles' selection was made by abstract analysis. Articles that considered interventions in healthy human beings were included. Results: Studies have concluded that a great cause of fatigue is sleep deprivation, and it was observed that shift workers have commonly felt excessive tiredness. The assumption is that shift work disrupts circadian rhythm and impairs sleep quality. Conclusion: Bad sleeping quality can increase the possibility of physical fatigue. The risk can be minimised with well-planned strategies. Application: The review article raises awareness of the importance of a healthy lifestyle and precautions in carrying out activities.
... These inconsistencies could be related to environmental and race conditions [5], as well as nutrition and intrinsic factors, such as fitness level and training background [2,3,9]. Therefore, several studies and reviews have indicated the importance of nutrition, especially carbohydrates and fluids intake, on race performance, body composition and muscle damage related blood indices, either during the tapering period [eg the period (less than 15 days) prior to the competition which is characterized by a reduction of training workload and maintenance or increase of training intensity, in order to allow the optimal/peak athlete's performance in a certain sports event] or during the race [10][11][12][13][14]. However, the majority of the studies in this field focus mainly on carbohydrate intake and its effect on endurance performance, in young runners. ...
... However, the majority of the studies in this field focus mainly on carbohydrate intake and its effect on endurance performance, in young runners. Even though protein consumption's protective effect on race/exercise/eccentric contraction-induced muscle damage is well described [10,[13][14][15][16][17][18], research investigating the effect of protein intake on race performance, race-induced muscle damage and body composition changes, is limited [10,14,16,19]. Furthermore, in master athletes, due to the ageinduced negative changes in body composition, mainly of lean body mass (LBM), muscle structure and function as well as metabolic procedures (e.g. ...
... Several time points after the race (0-72 hours post) could provide a better overview of the race induced changes in body composition and blood markers and the impact of nutrition on them. In addition, 3) the present study could not directly estimate whether race duration can Protein intake in master runners 13 lead to body composition and blood markers changes or vice versa. Finally, the reduction of LBM may be also a result of fluid loss. ...
Objective The aim of the present study was to investigate the relationships between protein intake (during the tapering period and the race), marathon performance, body composition, acute race induced changes and selected metabolic and muscle damage-related blood biomarkers, in recreational master runners. Methods In 58 experienced master runners (58.28 ± 1.07yr, 174.06 ± 0.72cm, 78.51 ± 0.76kg body mass, 21.38 ± 0.52% body fat, mean ± SEM), nutritional intake was evaluated one week before the race and during the marathon. Body composition was evaluated before and 2 hours after the race. Blood samples were collected at the same time points. Results Body fat and lean body mass were significantly reduced after the marathon race (p<0.01; η²: 0.311-0.888). Significant negative correlations were observed between energy intake from carbohydrates and proteins [expressed per lean body mass (LBM)], marathon performance and race induced changes of blood metabolic-muscle damage indices (p<0.05; r: -0.522 - -0.789). Positive correlations were observed between energy from carbohydrates and proteins per LBM, and body mass and LBM changes (p<0.05; r: 0.485 - 0.814). The specific contribution of protein intakes per LBM (B coefficient: -0.789–0.615) on race induced changes of body composition and blood markers was the same as that of carbohydrate intakes per LBM (B coefficient: -0.777–0.559). Conclusions Marathon race induced changes in body composition and metabolic blood indices are highly related to protein intake, either during the tapering period or during the race, with runners experiencing the lowest changes when consuming higher protein intakes.
... The daily protein intake goals should be met with a meal plan that provides a regular distribution of moderate amounts of high-quality protein throughout the day and after strenuous training sessions. These recommendations cover most training regimens and allow for flexible adjustments with periodic training and experience (33). Regarding the total protein intake of the participants, consumption of animal protein (78%) was almost four times higher than that of plant-based proteins such as legumes. ...
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Adolescent athletes require adequate energy and nutrient supply to support growth, development, and the demands associated with exercise and training. However, they are susceptible to nutritional inadequacies affecting their health and physical performance. Food choices with nutrient adequacy and environmental protection is crucial for a sustainable diet. Therefore, we aimed to assess the adequacy of low-carbon diets to meet the protein requirements of adolescent athletes. Therefore, a cross-sectional observational study was conducted with 91 adolescent athletes from sports clubs in Rio de Janeiro who underwent anthropometric and food consumption assessments. To estimate the environmental impact of anthropogenic activities, the sustainability indicators carbon footprint (CF) and water footprint (WF) were used. The CF of the athlete's diet was compared with the benchmark of 1,571 g CO2eq/cap/d estimated by the World Wildlife Fund (WWF). Protein recommendations according to the American Dietetic Association (ADA) for athletes and protein food groups according to the low-carbon EAT-Lancet reference diet were used as references. The results were stratified by sport modality, age, sex, and income range. The Mann-Whitney test was performed, followed by the Kruskal-Wallis test with Dunn's post-hoc test to assess the differences between groups using the statistical program GraphPad PRISM® version 8.0. CF and WF were directly associated with total energy intake, total protein intake, animal-origin protein intake, and the food groups of meat and eggs. Significant differences were observed in the environmental impact of diet based on sports groups and gender. The athletes' profile with higher environmental impact was male, middle-income class, and of any age group. The quartiles of CF of the overall diets were above the 1,571 g CO2eq/cap/d benchmark. Additionally, ADA's recommended range of daily protein consumption was met by most athletes, even in the lowest quartile of CF. Thus, a diet with a lower environmental impact can meet protein recommendations in adolescent athletes. The results found are of interest to the sports and food industries. It could help in designing a balanced diet for athletes as well as ensure less negative environmental impacts of food production and consumption.
... As is the case in health care and wellness, good nutrition plays a crucial role for athletes. Numerous studies have addressed the question of nutritional strategies that can contribute to improved performance and short recovery times [70][71][72][73][74]. ...
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Introduction: Continuous glucose monitoring (CGM) systems were primarily developed for patients with diabetes mellitus. However, these systems are increasingly being used by individuals who do not have diabetes mellitus. This mini review describes possible applications of CGM systems in healthy adults in health care, wellness, and sports. Results: CGM systems can be used for early detection of abnormal glucose regulation. Learning from CGM data how the intake of foods with different glycemic loads and physical activity affect glucose responses can be helpful in improving nutritional and/or physical activity behavior. Furthermore, states of stress that affect glucose dynamics could be made visible. Physical performance and/or regeneration can be improved as CGM systems can provide information on glucose values and dynamics that may help optimize nutritional strategies pre-, during, and post-exercise. Conclusions: CGM has a high potential for health benefits and self-optimization. More scientific studies are needed to improve the interpretation of CGM data. The interaction with other wearables and combined data collection and analysis in one single device would contribute to developing more precise recommendations for users.
... Carbohydrates are the primary energetic substrate for physical exercise and determine athletes' performance during moderate to high endurance sports [7][8][9]. Although muscle glycogen stores do not completely recover after a few hours of an exercise session, it is important that athletes follow nutritional recommendations to maximize their glycogen synthesis rate, focusing on the early phase of recovery (0-4 h) because of the slightly higher synthesis rates during this period [10]. ...
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Coffee is one of the most widely consumed beverages worldwide and caffeine is known to improve performance in physical exercise. Some substances in coffee have a positive effect on glucose metabolism and are promising for post-exercise muscle glycogen recovery. We investigated the effect of a coffee beverage after exhaustive exercise on muscle glycogen resynthesis, glycogen synthase activity and glycemic and insulinemic response in a double-blind, crossover, randomized clinical trial. Fourteen endurance-trained men performed an exhaustive cycle ergometer exercise to deplete muscle glycogen. The following morning, participants completed a second cycling protocol followed by a 4-h recovery, during which they received either test beverage (coffee + milk) or control (milk) and a breakfast meal, with a simple randomization. Blood samples and muscle biopsies were collected at the beginning and by the end of recovery. Eleven participants were included in data analysis (age: 39.0 ± 6.0 years; BMI: 24.0 ± 2.3 kg/m2; VO2max: 59.9 ± 8.3 mL·kg−1·min−1; PPO: 346 ± 39 W). The consumption of coffee + milk resulted in greater muscle glycogen recovery (102.56 ± 18.75 vs. 40.54 ± 18.74 mmol·kg dw−1; p = 0.01; d = 0.94) and greater glucose (p = 0.02; d = 0.83) and insulin (p = 0.03; d = 0.76) total area under the curve compared with control. The addition of coffee to a beverage with adequate amounts of carbohydrates increased muscle glycogen resynthesis and the glycemic and insulinemic response during the 4-h recovery after exhaustive cycling exercise.
Skeletal muscle is essential in locomotion and plays a role in whole-body metabolism, particularly during exercise. Skeletal muscle is the largest ‘reservoir’ of amino acids, which can be released for fuel and as a precursor for gluconeogenesis. During exercise, whole-body, and more specifically skeletal muscle, protein catabolism is increased, but protein synthesis is suppressed. Metabolism of skeletal muscle proteins can support energy demands during exercise, and persistent exercise (i.e. training) results in skeletal muscle protein remodelling. Exercise is generally classified as being either ‘strength’ or ‘aerobic/endurance’ in nature, and the type of exercise will reflect the phenotypic and metabolic adaptations of the muscle. In this chapter, we describe the impact of various exercise modes on protein metabolism during and following exercise.
Milk and dairy products with their distinct composition of carbohydrates, proteins, fats, and micronutrients are purported to have beneficial effects on human health. They have the potential to enhance exercise performance and recovery and are considered functional sport foods/beverages. This chapter summarizes the current evidence regarding the benefits of dairy products on endurance and resistance exercise, as well as the potential to augment health and performance in a variety of populations including team sport athletes, exercising children and adolescents, and aging adults. The impact of dairy products on weight loss and sleep quality is also discussed.
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Predictive microbiology aims to evaluate the effect of processing, distribution, and storage operations on microbiological food safety. It is based upon the premise that the response of population of microorganisms to environmental factors are reproducible, and that, by characterizing the environment in terms of identifiable, dominant factors controlling growth responses, it is possible, from past observations, to predict the responses of those microorganisms in other, similar environments. Predictive microbiology models represent the microbial responses to the environment. They are based mainly on observations made in synthetic culture media. Models cannot take into account all factors that may affect the microbial growth but select the most influential factors and only model their effects. The main assumptions of predictive microbiology and risk analysis are discussed in the present chapter. Moreover, the classification of predictive models and application in dairy processing are given. Finally, a case study using the tertiary model Sym’Previus software is presented.
β-glucans, the class of biological response modifier has unceasing attention, not only for its immune stimulating but also for its role as prebiotics, modulator of physiological events etc. and is widely used in the treatment of cancer, diabetes, gastrointestinal disorders, cardiovascular diseases etc. However, β-glucan with different physiochemical properties is found to have discrete clinical functions and thus careful selection of the types of β-glucan plays pivotal role in providing significant and expected clinical outcome. Herein this review, we presented the factors responsible for diverse functional properties of β-glucan, their distinct mode of actions in regulating human health etc. Further, clinical aspects of different β-glucans toward the management of wound care, metabolic dysbiosis, fatty liver disorders and endurance training associated energy metabolism were compiled and exhibited in detail.
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The research aims to examine the static and dynamic balance capacities of 5-9-year-old children who receive gymnastics training. The research group consists of 101 children, 21 boys and 80 girls, between the ages of 5-9 who are trained in gymnastics. Static balance (Flamingo balance test) and dynamic balance (Y balance test) tests, which are among the basic motor movement performance tests, were applied to examine the balance ability, one of the basic motor capacities of children aged 5-9. Arithmetic average and standard deviation, frequency and percentage distribution from general distribution statistics were obtained as data and Independent T test and One Way Anova tests were used to determine the significance levels between variables. With this research, it was concluded that the static and dynamic balance capacities of children who received gymnastics training at the age of 5-9 differ according to the age variable.
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Background: Protein supplements are frequently consumed by athletes and recreationally active adults to achieve greater gains in muscle mass and strength and improve physical performance. Objective: This review provides a systematic and comprehensive analysis of the literature that tested the hypothesis that protein supplements accelerate gains in muscle mass and strength resulting in improvements in aerobic and anaerobic power. Evidence statements were created based on an accepted strength of recommendation taxonomy. Data sources: English language articles were searched through PubMed and Google Scholar using protein and supplements together with performance, exercise, strength, and muscle, alone or in combination as keywords. Additional articles were retrieved from reference lists found in these papers. Study selection: Studies recruiting healthy adults between 18 and 50 years of age that evaluated the effects of protein supplements alone or in combination with carbohydrate on a performance metric (e.g., one repetition maximum or isometric or isokinetic muscle strength), metrics of body composition, or measures of aerobic or anaerobic power were included in this review. The literature search identified 32 articles which incorporated test metrics that dealt exclusively with changes in muscle mass and strength, 5 articles that implemented combined resistance and aerobic training or followed participants during their normal sport training programs, and 1 article that evaluated changes in muscle oxidative enzymes and maximal aerobic power. Study appraisal and synthesis methods: All papers were read in detail, and examined for experimental design confounders such as dietary monitoring, history of physical training (i.e., trained and untrained), and the number of participants studied. Studies were also evaluated based on the intensity, frequency, and duration of training, the type and timing of protein supplementation, and the sensitivity of the test metrics. Results: For untrained individuals, consuming supplemental protein likely has no impact on lean mass and muscle strength during the initial weeks of resistance training. However, as the duration, frequency, and volume of resistance training increase, protein supplementation may promote muscle hypertrophy and enhance gains in muscle strength in both untrained and trained individuals. Evidence also suggests that protein supplementation may accelerate gains in both aerobic and anaerobic power. Limitations: To demonstrate measureable gains in strength and performance with exercise training and protein supplementation, many of the studies reviewed recruited untrained participants. Since skeletal muscle responses to exercise and protein supplementation differ between trained and untrained individuals, findings are not easily generalized for all consumers who may be considering the use of protein supplements. Conclusions: This review suggests that protein supplementation may enhance muscle mass and performance when the training stimulus is adequate (e.g., frequency, volume, duration), and dietary intake is consistent with recommendations for physically active individuals.
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Background. Adequate protein ingestion-mediated stimulation of myofibrillar protein synthesis (MPS) is required to maintain skeletal muscle mass. It is currently unknown what per meal protein intake is required to maximally stimulate the response in older men and whether it differs from that of younger men. Methods. We retrospectively analyzed data from our laboratories that measured MPS in healthy older (~71 years) and younger (~22 years) men by primed constant infusion of l-ring-[13C6]phenylalanine after ingestion of varying amounts (0-40 g) of high-quality dietary protein as a single bolus and normalized to body mass and, where available, lean body mass (LBM). Results. There was no difference (p =. 53) in basal MPS rates between older (0.027±0.04%/h; means ± 95% CI) and young (0.028 ± 0.03%/h) men. Biphase linear regression and breakpoint analysis revealed the slope of first line segment was lower (p <. 05) in older men and that MPS reached a plateau after ingestion of 0.40 ± 0.19 and 0.24 ± 0.06 g/kg body mass (p =. 055) and 0.60 ± 0.29 and 0.25 ± 0.13 g/kg lean body mass (p <. 01) in older and younger men, respectively. Conclusions. This is the first report of the relative (to body weight) protein ingested dose response of MPS in younger and older men. Our data suggest that healthy older men are less sensitive to low protein intakes and require a greater relative protein intake, in a single meal, than young men to maximally stimulate postprandial rates of MPS. These results should be considered when developing nutritional solutions to maximize MPS for the maintenance or enhancement of muscle mass with advancing age. © 2014 © The Author 2014. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: [email protected] /* */
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Abstract Traditional nutritional approaches to endurance training have typically promoted high carbohydrate (CHO) availability before, during and after training sessions to ensure adequate muscle substrate to meet the demands of high daily training intensities and volumes. However, during the past decade, data from our laboratories and others have demonstrated that deliberately training in conditions of reduced CHO availability can promote training-induced adaptations of human skeletal muscle (i.e. increased maximal mitochondrial enzyme activities and/or mitochondrial content, increased rates of lipid oxidation and, in some instances, improved exercise capacity). Such data have led to the concept of 'training low, but competing high' whereby selected training sessions are completed in conditions of reduced CHO availability (so as to promote training adaptation), but CHO reserves are restored immediately prior to an important competition. The augmented training response observed with training-low strategies is likely regulated by enhanced activation of key cell signalling kinases (e.g. AMPK, p38MAPK), transcription factors (e.g. p53, PPARδ) and transcriptional co-activators (e.g. PGC-1α), such that a co-ordinated up-regulation of both the nuclear and mitochondrial genomes occurs. Although the optimal practical strategies to train low are not currently known, consuming additional caffeine, protein, and practising CHO mouth-rinsing before and/or during training may help to rescue the reduced training intensities that typically occur when 'training low', in addition to preventing protein breakdown and maintaining optimal immune function. Finally, athletes should practise 'train-low' workouts in conjunction with sessions undertaken with normal or high CHO availability so that their capacity to oxidise CHO is not blunted on race day.
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There have been significant changes in the understanding of the role of carbohydrates during endurance exercise in recent years, which allows for more specific and more personalized advice with regard to carbohydrate ingestion during exercise. The new proposed guidelines take into account the duration (and intensity) of exercise and advice is not restricted to the amount of carbohydrate; it also gives direction with respect to the type of carbohydrate. Studies have shown that during exercise lasting approximately 1 h in duration, a mouth rinse or small amounts of carbohydrate can result in a performance benefit. A single carbohydrate source can be oxidized at rates up to approximately 60 g/h and this is the recommendation for exercise that is more prolonged (2-3 h). For ultra-endurance events, the recommendation is higher at approximately 90 g/h. Carbohydrate ingested at such high ingestion rates must be a multiple transportable carbohydrates to allow high oxidation rates and prevent the accumulation of carbohydrate in the intestine. The source of the carbohydrate may be a liquid, semisolid, or solid, and the recommendations may need to be adjusted downward when the absolute exercise intensity is low and thus carbohydrate oxidation rates are also low. Carbohydrate intake advice is independent of body weight as well as training status. Therefore, although these guidelines apply to most athletes, they are highly dependent on the type and duration of activity. These new guidelines may replace the generic existing guidelines for carbohydrate intake during endurance exercise.
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Increasing amino acid availability (via infusion or ingestion) at rest or post-exercise enhances amino acid transport into human skeletal muscle. It is unknown whether alterations in amino acid availability, from ingesting different dietary proteins, can enhance amino acid transport rates and amino acid transporter (AAT) mRNA expression. We hypothesized that the prolonged hyperaminoacidemia from ingesting a blend of proteins with different digestion rates post-exercise would enhance amino acid transport into muscle and AAT expression as compared to the ingestion of a rapidly digested protein. In a double-blind, randomized clinical trial we studied 16 young adults at rest and after acute resistance exercise coupled with post-exercise (1h) ingestion of either a (soy-dairy) protein blend or whey protein. Phenylalanine net balance and transport rate into skeletal muscle were measured using stable isotopic methods in combination with femoral A-V blood sampling and muscle biopsies obtained at rest, 3 and 5h post-exercise. Phenylalanine transport into muscle and mRNA expression of select amino acid transporters (LAT1/SLC7A5, CD98/SLC3A2 SNAT2/SLC38A2, PAT1/SLC36A1, CAT1/SLC7A1) increased to a similar extent in both groups (P<0.05). However, the ingestion of the protein blend resulted in a prolonged and positive net phenylalanine balance during post-exercise recovery as compared to whey protein (P<0.05). Post-exercise myofibrillar protein synthesis increased similarly between groups. We conclude that while both protein sources enhanced post-exercise AAT expression, transport into muscle and myofibrillar protein synthesis, post-exercise ingestion of a protein blend results in a slightly prolonged net amino acid balance across the leg as compared to whey protein.
This review considers aspects of the optimal nutritional strategy for recovery from prolonged moderate to high intensity exercise Dietary carbohydrate represents a central component of post-exercise nutrition Therefore carbohydrate should be Ingested as early as possible in the post-exercise period and at frequent (i e 15- to 30-minute) intervals throughout recovery to maximize the rate of muscle glycogen resynthesis Solid and liquid carbohydrate supplements or whole foods can achieve this aim with equal effect but should be of high glycaemic index and Ingested following the feeding schedule described above at a rate of at least 1 g/kg/h in order to rapidly and sufficiently increase both blood glucose and insulin concentrations throughout recovery Adding >= 0 3 g/kg/h of protein to a carbohydrate supplement results in a synergistic increase in insulin secretion that can, in some circumstances, accelerate muscle glycogen resynthesis Specifically, if carbohydrate has not been ingested in quantities sufficient to maximize the rate of muscle glycogen resynthesis, the inclusion of protein may at least partially compensate for the limited availability of ingested carbohydrate Some studies have reported improved physical performance with ingestion of carbohydrate protein mixtures, both during exercise and during recovery prior to a subsequent exercise test While not all of the evidence supports these ergogenic benefits, there is clearly the potential for improved performance under certain conditions, e g if the additional protein increases the energy content of a supplement and/or the carbohydrate fraction is ingested at below the recommended rate The underlying mechanism for such effects may be partly due to increased muscle glycogen resynthesis during recovery, although there is varied support for other factors such as an increased central drive to exercise, a blunting of exercise-induced muscle damage, altered metabolism during exercise subsequent to recovery or a combination of these mechanisms
Laboratory-based studies demonstrate that fueling (carbohydrate; CHO) and fluid strategies can enhance training adaptations and race-day performance in endurance athletes. Thus, the aim of this case study was to characterize several periodized training and nutrition approaches leading to individualized race-day fluid and fueling plans for 3 elite male marathoners. The athletes kept detailed training logs on training volume, pace, and subjective ratings of perceived exertion (RPE) for each training session over 16 wk before race day. Training impulse/load calculations (TRIMP; min x RPE = load [arbitrary units; AU]) and 2 central nutritional techniques were implemented: periodic low-CHO-availability training and individualized CHO- and fluid-intake assessments. Athletes averaged ∼13 training sessions per week for a total average training volume of 182 km/wk and peak volume of 231 km/wk. Weekly TRIMP peaked at 4,437 AU (Wk 9), with a low of 1,887 AU (Wk 16) and an average of 3,082 ± 646 AU. Of the 606 total training sessions, ∼74%, 11%, and 15% were completed at an intensity in Zone 1 (very easy to somewhat hard), Zone 2 (at lactate threshold) and Zone 3 (very hard to maximal), respectively. There were 2.5 ± 2.3 low-CHO-availability training bouts per week. On race day athletes consumed 61 ± 15 g CHO in 604 ± 156 ml/hr (10.1% ± 0.3% CHO solution) in the following format: ∼15 g CHO in ∼150 ml every ∼15 min of racing. Their resultant marathon times were 2:11:23, 2:12:39 (both personal bests), and 2:16:17 (a marathon debut). Taken together, these periodized training and nutrition approaches were successfully applied to elite marathoners in training and competition.
BACKGROUND: It has been demonstrated that protein ingestion before sleep increases muscle protein synthesis rates during overnight recovery from an exercise bout. However, it remains to be established whether dietary protein ingestion before sleep can effectively augment the muscle adaptive response to resistance-type exercise training. OBJECTIVE: Here we assessed the impact of dietary protein supplementation before sleep on muscle mass and strength gains during resistance-type exercise training. METHODS: Forty-four young men (22 ± 1 y) were randomly assigned to a progressive, 12-wk resistance exercise training program. One group consumed a protein supplement containing 27.5 g of protein, 15 g of carbohydrate, and 0.1 g of fat every night before sleep. The other group received a noncaloric placebo. Muscle hypertrophy was assessed on a whole-body (dual-energy X-ray absorptiometry), limb (computed tomography scan), and muscle fiber (muscle biopsy specimen) level before and after exercise training. Strength was assessed regularly by 1-repetition maximum strength testing. RESULTS: Muscle strength increased after resistance exercise training to a significantly greater extent in the protein-supplemented (PRO) group than in the placebo-supplemented (PLA) group (+164 ± 11 kg and +130 ± 9 kg, respectively; P < 0.001). In addition, quadriceps muscle cross-sectional area increased in both groups over time (P < 0.001), with a greater increase in the PRO group than in the PLA group (+8.4 ± 1.1 cm(2) vs. +4.8 ± 0.8 cm(2), respectively; P < 0.05). Both type I and type II muscle fiber size increased after exercise training (P < 0.001), with a greater increase in type II muscle fiber size in the PRO group (+2319 ± 368 μm(2)) than in the PLA group (+1017 ± 353 μm(2); P < 0.05). CONCLUSION: Protein ingestion before sleep represents an effective dietary strategy to augment muscle mass and strength gains during resistance exercise training in young men. This trial was registered at as NCT02222415.
Recovery from the demands of daily training is an essential element of a scientifically based periodized program whose twin goals are to maximize training adaptation and enhance performance. Prolonged endurance training sessions induce substantial metabolic perturbations in skeletal muscle, including the depletion of endogenous fuels and damage/disruption to muscle and body proteins. Therefore, increasing nutrient availability (i.e., carbohydrate and protein) in the post-training recovery period is important to replenish substrate stores and facilitate repair and remodelling of skeletal muscle. It is well accepted that protein ingestion following resistance-based exercise increases rates of skeletal muscle protein synthesis and potentiates gains in muscle mass and strength. To date, however, little attention has focused on the ability of dietary protein to enhance skeletal muscle remodelling and stimulate adaptations that promote an endurance phenotype. The purpose of this review is to critically discuss the results of recent studies that have examined the role of dietary protein for the endurance athlete. Our primary aim is to consider the results from contemporary investigations that have advanced our knowledge of how the manipulation of dietary protein (i.e., amount, type, and timing of ingestion) can facilitate muscle remodelling by promoting muscle protein synthesis. We focus on the role of protein in facilitating optimal recovery from, and promoting adaptations to strenuous endurance-based training.