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    Food Absorption and The Aero Position

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    ChrisE

    Posts : 15
    Join date : 2010-02-17
    Age : 52
    Location : Maitland NSW

    Food Absorption and The Aero Position

    Post by ChrisE on Mon Feb 22, 2010 5:02 am

    The last two weeks I have been doing Full nutrition practice on my long rides.

    It is a very simple plan, Drink every 10 mins alternating water and gatorade, Gels at 20k, 40k, bar at 60k, gels at 80, 100, Bar 120 etc.

    This plan has worked well for me in my last 4 IM's so I am not really looking to change it unless I must.

    This year however, being significantly lighter than previous attempts I am able to sustain being aero for much longer. Consequently/Co-incidently I have found that absorption of my food intake isn't great. Last week at 150k I felt as though I was going to vomit with bloating and was almost ready to bonk. (ambient temp was on the top side of 35 deg). At this point I decided to stop and give myself a bit of recovery. I was still 50k from home. After 3 or 4 mins of walking around and being upright the nausea dissipated and although I still felt low on energy I was OK to continue. Within a couple of k's I had my 2nd wind and got home no troubles.

    This week again it happened but to a much lesser extent. The temp was around 30 and I didn't need to stop, but when I felt any bloating I sat up and let it pass.

    Has anyone experienced any similar issues from being aero? Or should I be looking at different causes e.g the heat?
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    Dave Tyno

    Posts : 182
    Join date : 2009-11-02
    Location : Brisbane

    Re: Food Absorption and The Aero Position

    Post by Dave Tyno on Mon Feb 22, 2010 6:26 am

    From what I've read - guys like Fluro et al - the fact you're able to stay aero for longer may mean you're going faster/pushing harder, so your gut isn't getting the blood it's used to getting.
    Sitting up and taking it easier would alleviate this.

    I don't know if it would normally pass in a couple of minutes though.
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    Paul F
    Coach

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    Re: Food Absorption and The Aero Position

    Post by Paul F on Mon Feb 22, 2010 1:23 pm

    ChrisE wrote:The last two weeks I have been doing Full nutrition practice on my long rides.

    It is a very simple plan, Drink every 10 mins alternating water and gatorade, Gels at 20k, 40k, bar at 60k, gels at 80, 100, Bar 120 etc.

    This plan has worked well for me in my last 4 IM's so I am not really looking to change it unless I must.

    This year however, being significantly lighter than previous attempts I am able to sustain being aero for much longer. Consequently/Co-incidently I have found that absorption of my food intake isn't great. Last week at 150k I felt as though I was going to vomit with bloating and was almost ready to bonk. (ambient temp was on the top side of 35 deg). At this point I decided to stop and give myself a bit of recovery. I was still 50k from home. After 3 or 4 mins of walking around and being upright the nausea dissipated and although I still felt low on energy I was OK to continue. Within a couple of k's I had my 2nd wind and got home no troubles.

    This week again it happened but to a much lesser extent. The temp was around 30 and I didn't need to stop, but when I felt any bloating I sat up and let it pass.

    Has anyone experienced any similar issues from being aero? Or should I be looking at different causes e.g the heat?

    G'day Chris,

    Can you break it down a little further in terms of how many calories per hour you were trying to consume and secondly, what sort of intensity were you riding at? It's pretty hard to have GI stress on long ride, because we don't swim beforehand, so I'd be curious to know how many calories you were consuming, and your ride intensity???. Apart from the gels, how much water and gatorade did you have, was there anything else?

    Can you give me a run down of that long ride, eg flat, hills, etc??

    Thanks Tyno, I have done quite a bit of research on GI stress and do have some beliefs about this very topic.


    fluro
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    Paul F
    Coach

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    Re: Food Absorption and The Aero Position

    Post by Paul F on Tue Feb 23, 2010 2:07 am

    Dave Tyno wrote:

    I don't know if it would normally pass in a couple of minutes though.

    G’day Tyno,

    I think potentially it can. When you’re suffering from GI distress, there is a huge demand for blood in and around your digestive system, but the supply is not there. The muscles demand (or it can be heat and blood moving towards your skin to control your body temperature) at race intensities is too high until you start to walk. The minute you begin walking blood can immediately shunt back to the digestive system to start the absorption process again. This is why you often see IM athletes running the slowest in the middle of an IM run; they need to active their digestive systems again. Once that happens they quite often they are able to run home the last 5km quite well.

    It’s not fitness that slows us down its pacing and nutrition on race day, we are all fit. We just need to make sure we set up pacing strategies and a nutrition plan to match the fitness we have.

    While nutrition is very important in IM’s, more importantly it is pacing, get this right and you greatly improve your ability to keep your digestive system active all day. If you screw up your pacing, then you’re shutting down your digestive systems ability to keep absorbing and processing calories at a consistent rate.

    A good sign that your are on track is that you should feel slightly hungry towards the end of the IM bike leg. If you do, then that is a good sign that you have an active digestive system, don’t use it as a sign to consume more. If you don’t have that feeling of hunger towards the end of the bike leg, then this could be a sign that your aren’t processing your calories and things could be getting backed up. Feeling full is a bad, remember we are only aiming for 250-350 cals per hour, so at no point should you feel full. Not feeling hungry is a sign that GI distress could be on its way.

    fluro
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    Julie H

    Posts : 51
    Join date : 2009-11-05
    Age : 42
    Location : Brisbane

    Re: Food Absorption and The Aero Position

    Post by Julie H on Fri Feb 26, 2010 2:02 am

    How about trying to drink/feed every 15 mins instead of every 10 minutes to give your body a chance to absorb what you are feeding it. It may help, just a suggestion
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    ChrisE

    Posts : 15
    Join date : 2010-02-17
    Age : 52
    Location : Maitland NSW

    Re: Food Absorption and The Aero Position

    Post by ChrisE on Sat Feb 27, 2010 5:57 am

    Thanks Guys,

    Sorry, I haven't been around for the last few days to see your replies.

    I'm a fairly simple triathlete in terms of nutrition doing what feels good rather than taking the scientific approach of aiming at cals/carbs per hour etc.

    My in take based over a two hour period on these rides looks like this:

    700ml Water
    700ml Gatorade (mixed to instruction - or Purchased pre-mixed)
    2 x Powerbar gels approx 110 cals each
    1 x Trail Bar approx 130 cals

    Intensity of ride Average HR range over last 3 long rides 143 to 148 which is firmly in the middle of Friels zone 2 for me (141-153)

    I am starting to think heat stress may be playing a part in this problem.

    Last 3 long Rides:

    12/2. 200km @ 28.9k 148avg 176max - ambient temp at end 38 Deg - Big issues (around 150k mark)
    20/2 170km @ 28.8k 143avg 174max - ambient temp at end 30 Deg - Lesser issues (around 130-140k)
    26/2 132km @ 33k 148avg 169 max - ambient temp at end 26 Deg - No issues

    As I mentioned previously this is a very simple nutrition plan (if you can call it that) that has worked for me over a number of years. But not so much over recent times. I'm not sure now is the time for me to start experimenting with different things 4 weeks out from Port.

    noknees
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    Paul F
    Coach

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    Join date : 2009-11-02

    Re: Food Absorption and The Aero Position

    Post by Paul F on Sat Feb 27, 2010 11:14 am

    G'day Chris,

    Your nutrition plan looks okay and so does your av hr. The problem lies with those max hr's. Depending on when you hit those in your rides, will influence how well you can keep your digestive tract active. At 174 and 176bpm your exceeding threshold and therefore you start the process of shutting down your digestive system because you increase demand for blood at the working muscle , which far exceed the demand to absorb those calories at your digestive system.

    How often were you hitting the 170's on those rides????

    Like you I have similar HR numbers, but on my long rides I'll average around 135-140bpm with my max at 150-155bpm. I never have GI distress because I eliminate those HR/power spikes. Mt threshold HR on the bike is 166bpm.

    Do the ride again but cap your HR closer to 160bpm and I can almost guarantee you won't have GI problems.
    The problem has nothing to do with your nutrition plan but everything to do with how you re executing your key sessions.

    Hope it helps

    fluro
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    ChrisE

    Posts : 15
    Join date : 2010-02-17
    Age : 52
    Location : Maitland NSW

    Re: Food Absorption and The Aero Position

    Post by ChrisE on Sun Feb 28, 2010 3:06 am

    Cheers Fluro,

    I'm not hitting the 170's too often. Maybe when having a dig over the top of a hill here and there. As you noted it's above my threshold and I don't like spending too much time there.

    That said the final average of my rides is in the 140's, this obviously evens out the time spent in the 150's 160's and the 120's 130's. Threshold on bike 172.

    I'll try next week to sit within the 10-15 bpm around zone 2 consistently rather than have the fluctuations and see how I go.

    Thanks for your time and input. It's much appreciated.

    Chris
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    Alex R
    **MicroMan World Record Holder**

    Posts : 353
    Join date : 2009-11-02

    Re: Food Absorption and The Aero Position

    Post by Alex R on Sun Feb 28, 2010 6:36 am

    Paul F wrote:

    exceeding threshold and therefore you start the process of shutting down your digestive system because you increase demand for blood at the working muscle , which far exceed the demand to absorb those calories at your digestive system.


    ..... I never have GI distress because I eliminate those HR/power spikes.

    ......... cap your HR closer to 160bpm and I can almost guarantee you won't have GI problems.
    .

    Hope it helps

    fluro

    Wise words indeed. Just a few spikes here ad there and my guts play up as well. This is why the ony semi reasonable IM I have had has been at Bsso as there is never any opportunity to spike it.
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    Paul F
    Coach

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    Re: Food Absorption and The Aero Position

    Post by Paul F on Sun Feb 28, 2010 1:29 pm

    Alex R wrote:
    Paul F wrote:

    exceeding threshold and therefore you start the process of shutting down your digestive system because you increase demand for blood at the working muscle , which far exceed the demand to absorb those calories at your digestive system.


    ..... I never have GI distress because I eliminate those HR/power spikes.

    ......... cap your HR closer to 160bpm and I can almost guarantee you won't have GI problems.
    .

    Hope it helps

    fluro

    Wise words indeed. Just a few spikes here ad there and my guts play up as well. This is why the ony semi reasonable IM I have had has been at Bsso as there is never any opportunity to spike it.

    Just to add, have you ever noticed how easy it is to push the pace after you come off a hill on the bike or run? Try it out. Run or bike a solid hill for 20-30min and then find a flat section and start TTing. You will absolutely fly, because you have shifted a high percentage of blood to the working muscles and therefore your muscles (bigger % of muscle fibres in fact) are being extremely well fuelled.

    It's like shifting form unleaded to high octane fuel. If the fuel is avaiable there is no stopping you. Laughing
    I'm still working how to not only keep the digestive system active but to also supply it with fuel that is easily digested and quickly converted into a useable source of energy. I honestly believe that is what matters most late in an IM.

    fluro

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