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00:00:01
yes thank you thank you very much thank you very much to the organise us uh
00:00:05
a market for the uh for the introduction and it's a great pleasure to uh to be here it's uh
00:00:12
doesn't take long uh to make a decision when you get an invitation to come to a place like this and actually i
00:00:19
said earlier to um uh boards that this is the place
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um whatever they give jeannie that is the place where
00:00:26
um i spend time writing uh my textbook of sports impression that's the place that i uh chose so
00:00:33
glad glad to be back here here i'm i'm
00:00:36
talking about sports impression for a young athletes
00:00:40
all i think the title in the program is fuelling uh the young athlete um
00:00:46
but i haven't actually done much work with uh with with young athletes all not an expert maybe an
00:00:53
hour little bit about school situation and we've done the research in the area of exercise metabolism but
00:01:00
as far as uh children goes at the moment i work with a few um academies um
00:01:06
but uh that's my daughter in the uh in the picture so um i well
00:01:12
try and put all this information that we have on sports addition put children together
00:01:18
a challenging in the time that we have but hopefully um
00:01:22
i can send you home with some food for thought
00:01:27
so i'm gonna talk about is this question our children small adults
00:01:35
and i think to answer that question we need to know a little bit
00:01:38
about exercise metabolism how that is different from children compared to adults
00:01:44
i'll talk about energy expenditure protein metabolism fruit balance carbohydrate and fat metabolism
00:01:50
and then once we have that picture clear we can talk about how does
00:01:54
that influence the nutrition requirements in terms of energy protein through its
00:02:00
carbohydrate intake maybe supplements and and can we actually come up with a recommendation
00:02:07
the problem um that we have sorry let me let me um give you the conclusion first
00:02:13
and then uh just just in case i miss you at the end um
00:02:18
and this conclusion may be fairly controversial but hopefully i can explain what what i mean by this
00:02:25
the conclusion is most guidelines for adult after it can also be applied to children
00:02:33
and that's sounds maybe a little bit strange uh maybe that goes
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a little bit against our comic emotions around this topic
00:02:41
um we bought the may also be some exceptions but
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hopefully i can convince you that a lot
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of the guidelines actually do a white who got at the cost of my presentation yeah but
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so most yeah most of the um i go back to
00:03:04
this so most of the um the guidelines i think can be applied um partly because i think
00:03:10
usually the the way that we into but the guidelines for adult
00:03:15
athletes that's way the problem is it's not so much
00:03:19
in the uh the kite on some cells will get that in them and
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first i wanna uh i want to identify two issues one is that
00:03:30
uh this is just if you if you them in that line at the uh the words
00:03:35
x. item metabolism as the search terms um you
00:03:39
get a number of uh publications um
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and of course it's it's very obvious that if you add the word
00:03:46
children that number of publications is uh is very very limited
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if you had the word sports um then the number of publications become even smaller
00:03:57
so what i'm gonna try and do is really on the basis of this data
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i'm gonna come up with some uh recommendations so very
00:04:06
challenging and all that you keep that in mind
00:04:09
that really we have very very little data on a on children
00:04:15
the other problem is how we interpret the studies that we do have available
00:04:20
and how we scale and most people here in the audience all very aware of this a problem
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um if we talk about performance how do we scale performance how do how do we compare
00:04:32
handles with children um or do we yeah that's running for example
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do we have to take like planks stride length into account um i
00:04:43
do we uh scale to body mass or do we
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scale too fat free mass do we compare at
00:04:49
absolute axes i wasn't hands these all relative exercise and and see some some of these issues will
00:04:55
well come up as i go through the uh through talk the example that idea um i use at the bottom
00:05:02
there is the effect of a sports wrinkle on metabolism
00:05:05
and performance if you're interested in that a topic
00:05:09
um then all of these factors are actually important because depending on how you measure performance
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uh how you express your measures of carbohydrate all fat
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metabolism you'll get completely different conclusions of course
00:05:24
oh
00:05:25
so let's start with uh with energy and that can be really
00:05:29
brief on on this topic because we have recommendations for
00:05:33
uh uh for for children for energy intake but as
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soon as you are talking about a young athletes
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and those recommendations of fairly meaningless because the the very large component
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uh all the energy expenditure for very active uh athletes
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is of course uh the uh the exercise uh itself so it's
00:05:56
impossible i think to give general recommendations on on energy intake
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um and that's also the the exercise component is also
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the uh the highly variable component in the
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died not finding the um one thing that i uh i want to say up front is
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my told is really about athletes and it is not about the general healthy diet and they
00:06:24
they are two very different discussions i think uh of course obesity is a problem
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um and of course there for we have to make sure that we
00:06:34
eat healthy up with that energy intake is not too high
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but here my talk is focused on athletes where all these the
00:06:41
really isn't the main issue the main issue is performance
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and and very often especially in the media dues to uh get confused
00:06:53
one of the arguments has been that it's um children use more energy because that that's sufficient
00:06:59
and this is partly based on the old studies by yeah they're all of a asked round
00:07:06
and we showed up running had a fixed intensity or a fixed a speed
00:07:13
and you can actually measure that that uh younger
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children uh less efficient all less economical
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uh other studies have shown that children maybe thirty percent less
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economical than or less efficient than uh than adults
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um but that's also difficult then sobered because if
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you correct that force try playing all
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uh treadmills be then uh that difference goes away so the that
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may not be intrinsically it different in the in the muscle
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it just may be a result of that you're comparing them at the same speed
00:07:52
that discussion i think is also fairly meaningless because even if there is a difference
00:07:59
the main variation and energy expenditure and everyone energy
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intake is gonna come from the exercise so
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of course we also have the issue of increased protein requirements and
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this is just a table of the r. d. a. recommendations
00:08:19
for the general population of for uh for children of different ages
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and you can see in that table that the requirements
00:08:28
are higher for younger athletes if you express protein intake per kilogram a body weight
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that's probably as a as expected uh it's very important to sport growth
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with a with protein now they are the aces some then that is sort of a minimum requirement
00:08:48
when we work with athletes that may not actually be that relevant we are looking for
00:08:53
what is the optimal amount of protein to support what this young athlete is uh doing
00:08:59
so the question is are these are the a.'s the meaningful
00:09:04
and very little literature and this is one study in fourteen year old
00:09:09
uh soccer players to train ten to twelve hours a week
00:09:13
so quite a quite a lot they use the technique called nitrogen balance
00:09:18
and to see how much protein is uh is really required
00:09:23
from that they actually come up with a higher number forty audi
00:09:27
a of one point four grams per kilogram that day
00:09:32
um so that would suggest that athletes who are uh training
00:09:37
a sample hours per week have higher a protein requirements
00:09:43
now i don't think that is a real issue because the vast majority almost all of the athlete
00:09:49
that i know at that age would eat more anyway then the one point four
00:09:53
grams per kilogram today so it's probably in practical terms unknown a she
00:10:00
yeah
00:10:02
now we move to thermal regulation because there there are
00:10:05
some differences there between um adults and children
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it's on the left you see the uh the child on the right the uh the adult
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and uh because of differences in the
00:10:18
uh surface area to mass ratio
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uh which is a much higher in the in the children um
00:10:27
conduction convection and radiation are really good ways to get rid of heat
00:10:32
and actually that's seems to work better in children then in adults
00:10:37
simply because of this uh service area to weight ratio
00:10:41
where there is a another difference is in the ability to cool down through sweating
00:10:48
um that is lower in children
00:10:53
there are a number of reasons for that this last swept us what land or less a sweat glands
00:11:00
so uh children can not get rid of heat as easily through a sweating as adults
00:11:08
now what's what implications does that have um it probably has no
00:11:15
implications in when you're exercising enough um a neutral environment
00:11:20
so fairly normal uh temperatures because uh children can get rid of
00:11:25
heat through other mechanisms but when you get to you
00:11:28
and temperatures where they yeah all the other ways to
00:11:33
get rid of heat are um on not affective
00:11:37
so very hot and humid um fireman's and you have to rely on sweating
00:11:42
that is where it becomes a little bit more problematic for children
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i usually that that is in in the guidelines for events that is taken into account
00:11:52
um there are usually more breaks in those uh the games to make
00:11:56
sure that uh that those um a fax negative effect or minimise
00:12:04
hydration may also play a a a roll 'em hash as you sweat
00:12:11
you become a de hydrated hand that may affect
00:12:16
the rate of change and rectal temperature
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now for a given a percentage or for a high
00:12:24
she lose body weight through uh through sweating
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the increase in rectal temperature core temperature is a greater in
00:12:32
children than it is in the apples that means that
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children are a little bit more at risk for
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these higher temperatures when they become a dehydrated
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um why is this a problem well it depends probably on the uh on the conditions
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um but it also has to be taken accounted all of
00:12:54
that is is expressed the kilogram body a body mass
00:12:58
and therefore the volumes that children would have to drink a much
00:13:02
smaller than the volumes that and i don't have to drink
00:13:05
but at some point so here's some of the conclusions of this uh first parts
00:13:11
of the small the person the launch of the surface to weight ratio
00:13:16
he'd conduction complexion radiation should be more and effective in children
00:13:23
as a result of that's what grade per unit service opus wetlands lower in children
00:13:30
children therefore sweat last there's actually two reasons uh because generally
00:13:35
he'd production of course is also last thing in children
00:13:39
good kilogram body mass sweat breaks are similar
00:13:45
and in what conditions core temperature may rise faster
00:13:48
in children with increasing levels of dehydration
00:13:54
as i said children generally have lower level so he production because the power outputs or lower
00:14:03
oh
00:14:07
the reviews studies but this is this is one of those uh studies here they
00:14:12
looked at fifty nine young lead male athletes in a variety of sports
00:14:18
and they measured how much these athletes de hydrated uh during yeah
00:14:23
and activities so they mentioned to change in a body mass
00:14:28
a percentage of the body of the body mass um one
00:14:33
of the fifty nine fifty four stay within within
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two percent and i think most people in the world would be great at staying within two percent is
00:14:45
no problem whatsoever so fifty four out of the fifty nine
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there is no no problem in terms of uh
00:14:53
dehydration we have one um actually to actually gains weight
00:15:01
um that is totally unnecessary to the advice would there
00:15:04
be my you can drink a little bit less
00:15:09
there are a couple of uh the people uh uh that's what between two and three percent
00:15:16
um whether that is an issue is probably depending on who
00:15:20
you talk to um i don't think that uh
00:15:24
anything on the three percent a body muscles is is an
00:15:29
issue unless you go to really extreme uh situations
00:15:34
um and then there are maybe a couple of people that
00:15:37
actually slept more than three percent dose would potentially the
00:15:41
the ones that uh that are at risk and those
00:15:44
are the ones that um would be worthwhile identify
00:15:49
now this is one study so ninety two percent of all the
00:15:54
athletes stay within that a safe uh save range no problems
00:16:00
um this is another study that uh that was conducted in
00:16:04
mostly in florida but different places in the world generally
00:16:08
in very hot climates i would say that eighty percent of this data was collected in
00:16:13
in hot climates eh these are all a
00:16:17
very good athletes mostly team sport athletes
00:16:21
um the data that you see here unfortunately is a mix
00:16:25
of a young and uh adult uh i think it's
00:16:31
um but i know that when you actually look at the break down of that data it there was
00:16:37
hardly any difference between young and older athletes in this in this particular population
00:16:44
so it here in the us what rates are a little bit higher than in the a previous study and i think
00:16:50
that is mostly due to a two factors one is that the body weight
00:16:56
in these athletes american sports was um was a little bit higher um
00:17:02
and also the studies were all done in very hot conditions so i would almost say that this is
00:17:08
the extreme of the uh of the picture so even notice whether it's now a little bit higher
00:17:14
they still still not ridiculously high body and uh maybe if you exceptions
00:17:23
when it comes to the uh risk heat illness then of
00:17:26
course the weather conditions are very important a fact so
00:17:30
the physiology sweat glands and this is um very important for uh
00:17:35
for children because that's where they potentially function a little bit
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less than a idols level of acclamation is important
00:17:45
the size intends these important and hypo hydration uh may also
00:17:50
the important i think if all of those factors
00:17:53
um but i at the same time that's in the in the central
00:17:58
that that's where you really aren't at risk for heat illness um
00:18:03
and then the best way to deal with that of course is to uh take away the or uh
00:18:08
d. yeah in terms the have more breaks uh don't have the uh
00:18:14
uh the training at that time of the a day i'm making sure that there's water available
00:18:22
so the conclusions from the the from this part reduce but raising children does not
00:18:27
seem to impair he'd lost during exercise in most conditions but in what conditions
00:18:32
um you have to be a little bit more careful typically you would see in most
00:18:37
activities for children one to two percent body weight loss not not an issue
00:18:43
um if those the body weight losses are greater
00:18:48
greater than three percent then i think we should follow the same guidelines as we use for at all that it's
00:18:56
oh
00:18:58
now i'm gonna talk about metabolism a little bit then the uh the
00:19:01
first there's a time line of the uh of the studies
00:19:05
um the uh the first study was in the nineteen thirties where they basically showed
00:19:10
the difference in the r. e. r. so carbohydrate and fat oxidation in uh
00:19:15
that in in children uh_huh uh children generally a better doctor dowsing trend
00:19:22
um if we go a little bit further to the nineteen seventies
00:19:27
i'll show you some data from that that was a um
00:19:30
still a lot of the shorts that we have around and nutrition for children based on that study
00:19:36
and it was studies where muscle biopsies were taken and since that time
00:19:41
and for some reason those studies have and then repeat it
00:19:46
um and then in the nineteen nineties some studies with exogenous carbohydrate oxidation
00:19:52
and so i'll i'll go and talk about somebody says studies the first couple i'll go really
00:19:58
quickly because i think it was also covered in the uh in in the last all
00:20:03
um children are a better anaerobic activities
00:20:09
they produce more uh um
00:20:15
uh so you the the children are not as good in the anaerobic activities they produce last uh lactate
00:20:21
um but they are a little bit more like and you're exactly
00:20:25
to where the aerobic capacity is very well the thought
00:20:32
we see this also in language and uh um glycogen stores in the uh in the muscle
00:20:40
oh
00:20:42
and when we measure fat oxidation and this is a a study
00:20:46
from mike yeah rebel and he measured a different stages
00:20:51
of acuity measured fat observation over a range of uh intense
00:20:56
these and eh em and found that uh um
00:21:02
that observation uh is best at the uh the uh at the early stages
00:21:11
when we ingest carbohydrate really reduce the um the uh fat observation uh um
00:21:19
but one of the striking findings is i think that children
00:21:23
when you express this per kilogram fat free mass
00:21:26
are more reliant on the ingested carbohydrates than adults and
00:21:32
some of this has to do i think with
00:21:34
the uh with the scaling and the fact that energy expenditure just channel i guess it's lower
00:21:41
so the conclusions from this part of children have less developed anaerobic energy systems
00:21:45
but well developed aerobic capacity let but usually say she is generally higher
00:21:52
um children use more exogenous carbide as if you will
00:21:58
and therefore when i combine all of this into some guidelines um
00:22:03
i didn't talk about this extreme carbohydrate loading not recommended
00:22:07
energy balance of course is important for growth the maturation didn't talk about that
00:22:13
carbohydrate intake during exercise well that really depends on
00:22:17
the goals the intensity and the duration
00:22:22
a fluid intake to limit fluid losses to about three percent
00:22:27
um what should you drink well water is probably sufficient in most cases
00:22:32
unless you have identified that the exercise intense these high enough
00:22:37
and iteration is long enough to warrant we use of carbohydrate
00:22:43
didn't talk about supplements but put solutions uh should always be preferred yeah instead of
00:22:48
supplements and no need to supplement it it's not a necessary of course
00:22:54
and the general recommendation is no supplements but the reality is of course
00:22:59
that eighty percent of of young athletes uh are using supplements
00:23:08
so the guidelines for adults really are very simple and depend
00:23:13
very much on the goals of that they the
00:23:16
intensity and the duration of the exercise and it is not different in that should say young athletes
00:23:23
so if we talk about supplements concentration the balance tired i think we should start at the bottom
00:23:31
make sure that there's enough attention for the uh for the diet if there is a need we
00:23:37
useful situation and uh and at the very last resort we yeah we talk about supplements so
00:23:44
it's one that leave you with that uh that last slide that uh i
00:23:47
think the futures will situation it's not this debate we have about high
00:23:51
fat or high cock diets it is really about personalising it to the individual

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Conference program

Welcome
Frederic Koehn, President Young Athletes Forum Foundation
21 Sept. 2017 · 1:18 p.m.
3,138 views
Opening address
Boris GOJANOVIC
21 Sept. 2017 · 1:22 p.m.
131 views
Biological Maturation and the Path to Success: Before and After the Fact
Manuel COELHO-E-SILVA, Biological Maturation and the Path to Success: Before and After the Fact
21 Sept. 2017 · 1:31 p.m.
559 views
Designing pathways to success – part kaleidoscope, part microscope
Jason GULBIN, Designing pathways to success – part kaleidoscope, part microscope
21 Sept. 2017 · 1:53 p.m.
386 views
Talent ID and Development: Why doing the “right thing” is not always the “best thing
Ross TUCKER , Talent ID and Development: Why doing the “right thing” is not always the “best thing
21 Sept. 2017 · 2:16 p.m.
341 views
108 views
Resistance training during long-term athlete development
Urs GRANACHER
21 Sept. 2017 · 2:52 p.m.
366 views
The development of aerobic power in young athletes
Grégoire MILLET
21 Sept. 2017 · 3:15 p.m.
1,475 views
Fueling the young athlete
Asker JEUKENDRUP
21 Sept. 2017 · 3:36 p.m.
195 views
Training young athletes: challenges and opportunities
Marco CARDINALE
21 Sept. 2017 · 4:01 p.m.
183 views
TRAINING THE YOUNG ATHLETE - Q&A
Panel
21 Sept. 2017 · 4:33 p.m.
Coaching from junior to the top of the world (Lara Gut)
Patrick Flaction, Elitment
21 Sept. 2017 · 5:20 p.m.
195 views
Knee ligament injuries in immature athletes
Franck CHOTEL
22 Sept. 2017 · 7:48 a.m.
Osteochondral lesions
Franck ACCADBLED
22 Sept. 2017 · 8:11 a.m.
225 views
INJURIES WITH THE ORTHOPEDISTS - Q&A
Panel
22 Sept. 2017 · 8:54 a.m.
Back pain in young athletes
Liba SHEERAN
22 Sept. 2017 · 9:34 a.m.
Long term sequelae of youth overuse injuries
Mark BATT
22 Sept. 2017 · 10:19 a.m.
OVERUSE INJURIES - Q&A
Panel
22 Sept. 2017 · 10:40 a.m.
Concussions in young athletes : myths and reality
Christopher NEWMAN
22 Sept. 2017 · 10:52 a.m.
Screening for heart disease in sports – nonsense or necessary?
Matthias WILHELM
22 Sept. 2017 · 11:16 a.m.
Competitive Sport & Health: hidden issues
Gordon MATHESON
22 Sept. 2017 · 12:04 p.m.
Injury prevention programs : The 11+ Kids Project
Mario BIZZINI
22 Sept. 2017 · 2:12 p.m.
104 views
159 views
Parents’ Knowledge of Sport Psychology and Nutrition
Dr Camilla J. Knight
22 Sept. 2017 · 3:57 p.m.
Closing Address
Frederic Koehn, President Young Athletes Forum Foundation
22 Sept. 2017 · 6:04 p.m.