Post-Exercise Caffeine Helps Muscles Refuel

--------------------------------------- ----------------------------------

Recipe to recover more quickly from exercise: Finish workout, eat pasta, and wash down with five or six cups of strong coffee.


Glycogen, the muscle's primary fuel source during exercise, is
replenished more rapidly when athletes ingest both carbohydrate and
caffeine following exhaustive exercise, new research from the online
edition of theJournal of Applied Physiology
shows. Athletes who ingested caffeine with carbohydrate had 66% more
glycogen in their muscles four hours after finishing intense,
glycogen-depleting exercise, compared to when they consumed
carbohydrate alone, according to the study, published by The American Physiological Society.


The study, "High rates of muscle glycogen resynthesis after exhaustive
exercise when carbohydrate is co-ingested with caffeine," is by David
J. Pedersen, Sarah J. Lessard, Vernon G. Coffey, Emmanuel G. Churchley,
Andrew M. Wootton, They Ng, Matthew J. Watt and John A. Hawley. Dr.
Pedersen is with the Garvan Institute of Medical Research in Sydney,
Australia, Dr. Watt is from St. Vincent's Institute of Medical
Research, Fitzroy, Victoria, Australia. All others are with the Royal
Melbourne Institute of Technology University (RMIT) in Bundoora,
Victoria, Australia.



A fuller audio interview with Dr. Hawley is available in Episode 11 of the APS podcast, Life Lines, at www.lifelines.tv.
The show also includes an interview with Dr. Stanley Schultz, whose
physiological discovery of how sugar is transported in the gut led to
the development of oral rehydration therapy and sports drinks such as
Gatorade.



Caffeine aids carbohydrate uptake

It is already
established that consuming carbohydrate and caffeine prior to and
during exercise improves a variety of athletic performances. This is
the first study to show that caffeine combined with carbohydrates
following exercise can help refuel the muscle faster.


"If you have 66% more fuel for the next day's training or competition,
there is absolutely no question you will go farther or faster," said
Dr. Hawley, the study's senior author. Caffeine is present in common
foods and beverages, including coffee, tea, chocolate and cola drinks.


The study was conducted on seven well-trained endurance cyclists who
participated in four sessions. The participants first rode a cycle
ergometer until exhaustion, and then consumed a low-carbohydrate dinner
before going home. This exercise bout was designed to reduce the
athletes' muscle glycogen stores prior to the experimental trial the
next day.


The athletes did not eat again until they returned to the lab the next
day for the second session when they again cycled until exhaustion.
They then ingested a drink that contained carbohydrate alone or
carbohydrate plus caffeine and rested in the laboratory for four hours.
During this post-exercise rest time, the researchers took several
muscle biopsies and multiple blood samples to measure the amount of
glycogen being replenished in the muscle, along with the concentrations
of glucose-regulating metabolites and hormones in the blood, including
glucose and insulin.


The entire two-session process was repeated 7-10 days later. The only
difference was that this time, the athletes drank the beverage that
they had not consumed in the previous trial. (That is, if they drank
the carbohydrate alone in the first trial, they drank the carbohydrate
plus caffeine in the second trial, and vice versa.)


The drinks looked, smelled and tasted the same and both contained the
same amount of carbohydrate. Neither the researchers nor the cyclists
knew which regimen they were receiving, making it a double-blind,
placebo-controlled experiment.



Glucose and insulin levels higher with caffeine ingestion


The researchers found the following:


- one hour after exercise, muscle glycogen levels had replenished to
the same extent whether or not the athlete had the drink containing
carbohydrate and caffeine or carbohydrate only


- four hours after exercise, the drink containing caffeine resulted in
66% higher glycogen levels compared to the carbohydrate-only drink


- throughout the four-hour recovery period, the caffeinated drink
resulted in higher levels of blood glucose and plasma insulin


- several signaling proteins believed to play a role in glucose
transport into the muscle were elevated to a greater extent after the
athletes ingested the carbohydrate-plus-caffeine drink, compared to the
carbohydrate-only drink


Dr. Hawley said it is not yet clear how caffeine aids in facilitating
glucose uptake from the blood into the muscles. However, the higher
circulating blood glucose and plasma insulin levels were likely to be a
factor. In addition, caffeine may increase the activity of several
signaling enzymes, including the calcium-dependent protein kinase and
protein kinase B (also called Akt), which have roles in muscle glucose
uptake during and after exercise.


Lower dose is next step


In this study, the researchers used a high dose of caffeine to
establish that it could help the muscles convert ingested carbohydrates
to glycogen more rapidly. However, because caffeine can have
potentially negative effects, such as disturbing sleep or causing
jitteriness, the next step is to determine whether smaller doses could
accomplish the same goal.


Hawley pointed out that the responses to caffeine ingestion vary widely
between individuals. Indeed, while several of the athletes in the study
said they had a difficult time sleeping the night after the trial in
which they ingested caffeine (8 mg per kilogram of body weight, the
equivalent of drinking 5-6 cups of strong coffee), several others fell
asleep during the recovery period and reported no adverse effects.


Athletes who want to incorporate caffeine into their workouts should
experiment during training sessions well in advance of an important
competition to find out what works for them.


Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS) has been an integral part of this scientific discovery process since it was established in 1887.


Post-Exercise Caffeine Helps Muscles Refuel

Post-Exercise Caffeine Helps Muscles Refuel

--------------------------------------- ----------------------------------

Recipe to recover more quickly from exercise: Finish workout, eat pasta, and wash down with five or six cups of strong coffee.


Glycogen, the muscle's primary fuel source during exercise, is
replenished more rapidly when athletes ingest both carbohydrate and
caffeine following exhaustive exercise, new research from the online
edition of theJournal of Applied Physiology
shows. Athletes who ingested caffeine with carbohydrate had 66% more
glycogen in their muscles four hours after finishing intense,
glycogen-depleting exercise, compared to when they consumed
carbohydrate alone, according to the study, published by The American Physiological Society.


The study, "High rates of muscle glycogen resynthesis after exhaustive
exercise when carbohydrate is co-ingested with caffeine," is by David
J. Pedersen, Sarah J. Lessard, Vernon G. Coffey, Emmanuel G. Churchley,
Andrew M. Wootton, They Ng, Matthew J. Watt and John A. Hawley. Dr.
Pedersen is with the Garvan Institute of Medical Research in Sydney,
Australia, Dr. Watt is from St. Vincent's Institute of Medical
Research, Fitzroy, Victoria, Australia. All others are with the Royal
Melbourne Institute of Technology University (RMIT) in Bundoora,
Victoria, Australia.



A fuller audio interview with Dr. Hawley is available in Episode 11 of the APS podcast, Life Lines, at www.lifelines.tv.
The show also includes an interview with Dr. Stanley Schultz, whose
physiological discovery of how sugar is transported in the gut led to
the development of oral rehydration therapy and sports drinks such as
Gatorade.



Caffeine aids carbohydrate uptake

It is already
established that consuming carbohydrate and caffeine prior to and
during exercise improves a variety of athletic performances. This is
the first study to show that caffeine combined with carbohydrates
following exercise can help refuel the muscle faster.


"If you have 66% more fuel for the next day's training or competition,
there is absolutely no question you will go farther or faster," said
Dr. Hawley, the study's senior author. Caffeine is present in common
foods and beverages, including coffee, tea, chocolate and cola drinks.


The study was conducted on seven well-trained endurance cyclists who
participated in four sessions. The participants first rode a cycle
ergometer until exhaustion, and then consumed a low-carbohydrate dinner
before going home. This exercise bout was designed to reduce the
athletes' muscle glycogen stores prior to the experimental trial the
next day.


The athletes did not eat again until they returned to the lab the next
day for the second session when they again cycled until exhaustion.
They then ingested a drink that contained carbohydrate alone or
carbohydrate plus caffeine and rested in the laboratory for four hours.
During this post-exercise rest time, the researchers took several
muscle biopsies and multiple blood samples to measure the amount of
glycogen being replenished in the muscle, along with the concentrations
of glucose-regulating metabolites and hormones in the blood, including
glucose and insulin.


The entire two-session process was repeated 7-10 days later. The only
difference was that this time, the athletes drank the beverage that
they had not consumed in the previous trial. (That is, if they drank
the carbohydrate alone in the first trial, they drank the carbohydrate
plus caffeine in the second trial, and vice versa.)


The drinks looked, smelled and tasted the same and both contained the
same amount of carbohydrate. Neither the researchers nor the cyclists
knew which regimen they were receiving, making it a double-blind,
placebo-controlled experiment.



Glucose and insulin levels higher with caffeine ingestion


The researchers found the following:


- one hour after exercise, muscle glycogen levels had replenished to
the same extent whether or not the athlete had the drink containing
carbohydrate and caffeine or carbohydrate only


- four hours after exercise, the drink containing caffeine resulted in
66% higher glycogen levels compared to the carbohydrate-only drink


- throughout the four-hour recovery period, the caffeinated drink
resulted in higher levels of blood glucose and plasma insulin


- several signaling proteins believed to play a role in glucose
transport into the muscle were elevated to a greater extent after the
athletes ingested the carbohydrate-plus-caffeine drink, compared to the
carbohydrate-only drink


Dr. Hawley said it is not yet clear how caffeine aids in facilitating
glucose uptake from the blood into the muscles. However, the higher
circulating blood glucose and plasma insulin levels were likely to be a
factor. In addition, caffeine may increase the activity of several
signaling enzymes, including the calcium-dependent protein kinase and
protein kinase B (also called Akt), which have roles in muscle glucose
uptake during and after exercise.


Lower dose is next step


In this study, the researchers used a high dose of caffeine to
establish that it could help the muscles convert ingested carbohydrates
to glycogen more rapidly. However, because caffeine can have
potentially negative effects, such as disturbing sleep or causing
jitteriness, the next step is to determine whether smaller doses could
accomplish the same goal.


Hawley pointed out that the responses to caffeine ingestion vary widely
between individuals. Indeed, while several of the athletes in the study
said they had a difficult time sleeping the night after the trial in
which they ingested caffeine (8 mg per kilogram of body weight, the
equivalent of drinking 5-6 cups of strong coffee), several others fell
asleep during the recovery period and reported no adverse effects.


Athletes who want to incorporate caffeine into their workouts should
experiment during training sessions well in advance of an important
competition to find out what works for them.


Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS) has been an integral part of this scientific discovery process since it was established in 1887.


Post-Exercise Caffeine Helps Muscles Refuel

Post-Exercise Caffeine Helps Muscles Refuel

--------------------------------------- ----------------------------------

Recipe to recover more quickly from exercise: Finish workout, eat pasta, and wash down with five or six cups of strong coffee.


Glycogen, the muscle's primary fuel source during exercise, is
replenished more rapidly when athletes ingest both carbohydrate and
caffeine following exhaustive exercise, new research from the online
edition of theJournal of Applied Physiology
shows. Athletes who ingested caffeine with carbohydrate had 66% more
glycogen in their muscles four hours after finishing intense,
glycogen-depleting exercise, compared to when they consumed
carbohydrate alone, according to the study, published by The American Physiological Society.


The study, "High rates of muscle glycogen resynthesis after exhaustive
exercise when carbohydrate is co-ingested with caffeine," is by David
J. Pedersen, Sarah J. Lessard, Vernon G. Coffey, Emmanuel G. Churchley,
Andrew M. Wootton, They Ng, Matthew J. Watt and John A. Hawley. Dr.
Pedersen is with the Garvan Institute of Medical Research in Sydney,
Australia, Dr. Watt is from St. Vincent's Institute of Medical
Research, Fitzroy, Victoria, Australia. All others are with the Royal
Melbourne Institute of Technology University (RMIT) in Bundoora,
Victoria, Australia.



A fuller audio interview with Dr. Hawley is available in Episode 11 of the APS podcast, Life Lines, at www.lifelines.tv.
The show also includes an interview with Dr. Stanley Schultz, whose
physiological discovery of how sugar is transported in the gut led to
the development of oral rehydration therapy and sports drinks such as
Gatorade.



Caffeine aids carbohydrate uptake

It is already
established that consuming carbohydrate and caffeine prior to and
during exercise improves a variety of athletic performances. This is
the first study to show that caffeine combined with carbohydrates
following exercise can help refuel the muscle faster.


"If you have 66% more fuel for the next day's training or competition,
there is absolutely no question you will go farther or faster," said
Dr. Hawley, the study's senior author. Caffeine is present in common
foods and beverages, including coffee, tea, chocolate and cola drinks.


The study was conducted on seven well-trained endurance cyclists who
participated in four sessions. The participants first rode a cycle
ergometer until exhaustion, and then consumed a low-carbohydrate dinner
before going home. This exercise bout was designed to reduce the
athletes' muscle glycogen stores prior to the experimental trial the
next day.


The athletes did not eat again until they returned to the lab the next
day for the second session when they again cycled until exhaustion.
They then ingested a drink that contained carbohydrate alone or
carbohydrate plus caffeine and rested in the laboratory for four hours.
During this post-exercise rest time, the researchers took several
muscle biopsies and multiple blood samples to measure the amount of
glycogen being replenished in the muscle, along with the concentrations
of glucose-regulating metabolites and hormones in the blood, including
glucose and insulin.


The entire two-session process was repeated 7-10 days later. The only
difference was that this time, the athletes drank the beverage that
they had not consumed in the previous trial. (That is, if they drank
the carbohydrate alone in the first trial, they drank the carbohydrate
plus caffeine in the second trial, and vice versa.)


The drinks looked, smelled and tasted the same and both contained the
same amount of carbohydrate. Neither the researchers nor the cyclists
knew which regimen they were receiving, making it a double-blind,
placebo-controlled experiment.



Glucose and insulin levels higher with caffeine ingestion


The researchers found the following:


- one hour after exercise, muscle glycogen levels had replenished to
the same extent whether or not the athlete had the drink containing
carbohydrate and caffeine or carbohydrate only


- four hours after exercise, the drink containing caffeine resulted in
66% higher glycogen levels compared to the carbohydrate-only drink


- throughout the four-hour recovery period, the caffeinated drink
resulted in higher levels of blood glucose and plasma insulin


- several signaling proteins believed to play a role in glucose
transport into the muscle were elevated to a greater extent after the
athletes ingested the carbohydrate-plus-caffeine drink, compared to the
carbohydrate-only drink


Dr. Hawley said it is not yet clear how caffeine aids in facilitating
glucose uptake from the blood into the muscles. However, the higher
circulating blood glucose and plasma insulin levels were likely to be a
factor. In addition, caffeine may increase the activity of several
signaling enzymes, including the calcium-dependent protein kinase and
protein kinase B (also called Akt), which have roles in muscle glucose
uptake during and after exercise.


Lower dose is next step


In this study, the researchers used a high dose of caffeine to
establish that it could help the muscles convert ingested carbohydrates
to glycogen more rapidly. However, because caffeine can have
potentially negative effects, such as disturbing sleep or causing
jitteriness, the next step is to determine whether smaller doses could
accomplish the same goal.


Hawley pointed out that the responses to caffeine ingestion vary widely
between individuals. Indeed, while several of the athletes in the study
said they had a difficult time sleeping the night after the trial in
which they ingested caffeine (8 mg per kilogram of body weight, the
equivalent of drinking 5-6 cups of strong coffee), several others fell
asleep during the recovery period and reported no adverse effects.


Athletes who want to incorporate caffeine into their workouts should
experiment during training sessions well in advance of an important
competition to find out what works for them.


Physiology is the study of how molecules, cells, tissues and organs function to create health or disease. The American Physiological Society (APS) has been an integral part of this scientific discovery process since it was established in 1887.


Post-Exercise Caffeine Helps Muscles Refuel