Gels for a half?

long_b

Do you use gels during a half marathon?

frankeee

long_b wrote: »

Do you use gels during a half marathon?

I generally do, while it's obviously a different beast than a full, I find a caffeinated gel at around mile 9 or 10 gives me the boost not to slow down for the last few miles. On the down side though I do find it a lot tougher to get it down running at HM pace rather than full.

NetwerkErrer

No. The distance is short enough that you don't need to take on extra carbs unless you are pretty much malnourished or training straight through it without a taper and still have a bad diet. They're not necessary for a half and at best will give a slight mental boost but at worst, mess up your stomach and a pit stop could be called for.

If you haven't taken gels in training, raceday isn't the time to start experimenting. Just eat well and you don't need to take on extra energy for a half.

TFBubendorfer

frankeee wrote: »

I generally do, while it's obviously a different beast than a full, I find a caffeinated gel at around mile 9 or 10 gives me the boost not to slow down for the last few miles.

I've done that as well at times. It's most likely all in the head as you should not run out of energy in a half marathon, but things that go on in your head are just as important as your legs.

Wubble Wubble

I've run seven half marathons, and never taken a gel in any of them; IMO no need, not a long enough distance. The one full I have run, I didn't bother either. I only ever took them during one or two LSRs, and while they might have made a small difference, they didn't taste great, and I didn't go out of my way to buy more!

However, some others here and elsewhere, including runners far more experienced than me, swear by them. Different strokes for different folks I suppose.

demfad

TFBubendorfer wrote: »

I've done that as well at times. It's most likely all in the head as you should not run out of energy in a half marathon, but things that go on in your head are just as important as your legs.

Id agree with that. I often take a diuralyte or Gel 2/3 of the way into similar races. Youll actually feel the diuralyte (salt) in the legs especially on a tough course. As you say there is a definate mental boost from taking either at this point in the race (the psychologically hardest part) which is very useful IMO for recreational runners.

adrian522

Would it be the case that a gel may be useful for slower runners? i.e if you are out there for more than 2 hours does it become a more physical benefit? I understand if you are running 90 mins for the half that there should be no need but I thought if you were running over 2 hours you could do with topping up on Carbs during the race?

robinph

I certainly don't believe they are needed for half marathon distances for their stated purpose, ie giving your muscles energy to get to the finish.


However, as I think I was saying to someone in the post VMLM recovery session on Sunday, I do take gels for any distance over an hour but mainly for the purpose of keeping my brain functioning. This is not an issue for most of you on here though if you have a fully functioning pancreas.

Ceepo

demfad wrote: »

Id agree with that. I often take a diuralyte or Gel 2/3 of the way into similar races. Youll actually feel the diuralyte (salt) in the legs especially on a tough course.

I'm lost here can you explain to me how you actually feel the salt in your legs. ?
Thanks

overpronator

I'd be another who would take a gel during a half, usually around 9 miles. You definitely don't need the carbs, that bit is clear, but I think the caffeine has pushed me along in the latter stages. I've usually done halfs in the buildup to full marathons too so its handy to get used to taking them at "speed". Don't underestimate the impact of the placebo effect either.

DocQismyJesus

I'm pretty much in agreement with a couple of the lads here. IMO the mental part of racing is the hardest part to get right. I've taken a beet it shot before all my recent best runs- do I need it? No. But it helps my confidence and that's all that counts. A gel certainly won't do harm (unless stomach issues have been a problem before)

Clearlier

adrian522 wrote: »

Would it be the case that a gel may be useful for slower runners? i.e if you are out there for more than 2 hours does it become a more physical benefit? I understand if you are running 90 mins for the half that there should be no need but I thought if you were running over 2 hours you could do with topping up on Carbs during the race?

Yes, the need for carbs is a function of how long you're running for, your ability to burn fat and the intensity of your running. The actual distance isn't really relevant except in determining the above.

Someone who is going to take 2 and a half hours to complete a half is almost certainly (no doubt there will be the odd exception) going to benefit from taking something. The first half I ever ran took me 2 hours and 48 seconds. I was on course for 1:57 up to 11 miles when I bonked. I wasn't well trained and try as I might I had to watch the 2 hour goals slip through my fingers. I've since run one in 1:27 and had no need to take anything on board.

The other scenario where someone might take a gel in a half is where they're training for a marathon and want to practice taking one in a race situation.

NetwerkErrer

adrian522 wrote: »

Would it be the case that a gel may be useful for slower runners? i.e if you are out there for more than 2 hours does it become a more physical benefit? I understand if you are running 90 mins for the half that there should be no need but I thought if you were running over 2 hours you could do with topping up on Carbs during the race?

The thing with the 2 hour glycogen rule is it's flawed. Distance travelled and relative pace to individual fitness is the big thing when it comes to calorie use. You burn calories by the distance travelled and not the time it takes to cover that distance. That is why you see elite athletes bonking at 20 miles even though they have only been running over 90 minutes. It's the distance and individual pace that determines how quickly or slowly you burn through the glycogen stores, the overall time on the feet has no bearing on it.

NetwerkErrer

Clearlier wrote: »

Yes, the need for carbs is a function of how long you're running for, your ability to burn fat and the intensity of your running. The actual distance isn't really relevant except in determining the above

Actually not true. Check out the ACSM formula for calorie expenditure. I actually posted it in the random running questions thread a couple of months ago.

Clearlier

NetwerkErrer wrote: »

Actually not true. Check out the ACSM formula for calorie expenditure. I actually posted it in the random running questions thread a couple of months ago.

Any chance that you could expand on that a little NE? I've had a quick google for "ACSM formula for calorie expenditure" and it seems to be suggesting that two people of the same weight burn calories at the same rate. I'm guessing that it must be a little more complex but that brief understanding that I've got from it is a touch simplistic.

DocQismyJesus

NetwerkErrer wrote: »

Actually not true. Check out the ACSM formula for calorie expenditure. I actually posted it in the random running questions thread a couple of months ago.

Maybe so NE but they essentially boil down to the same thing which is less trained/ less experienced runners burn through sugar quicker - hence bonks at 11 miles instead of 20

NetwerkErrer

.

The use of glycogen to fat is a factor of what system you're relying on in an individual race so the difference will be minimal between a 90 minute and 2 hour 15 half runner because they will be relying on pretty much the same system. In fact, the 90 minute runner will burn more glycogen as they are running closer to LT

robinph

NetwerkErrer wrote: »

The thing with the 2 hour glycogen rule is it's flawed. Distance travelled and relative pace to individual fitness is the big thing when it comes to calorie use. You burn calories by the distance travelled and not the time it takes to cover that distance. That is why you see elite athletes bonking at 20 miles even though they have only been running over 90 minutes. It's the distance and individual pace that determines how quickly or slowly you burn through the glycogen stores, the overall time on the feet has no bearing on it.

I'm not actually certain if the gels would have a whole lot of difference to the bonking or not at 20 miles anyway. I have still fallen apart at that point in marathons despite having downing gels on a regimented basis for the duration in order to keep blood sugar levels where I need them.

How much of the good stuff in a gel actually makes it to your muscles or not? It certainly makes it to my brain so prevents me falling over, but not sure it's being much use to the muscles.

NetwerkErrer

NetwerkErrer wrote: »

Here we go. Quick copy and paste as I'm not doing the math again.

The overall amount of energy will remain almost identical for a 20 mile run even if you run it at 5 min/mile pace or 10 min/mile pace. The only difference will be glycogen to fat ratio.

Using the ACSM formula for running

VO2 = (0.2v)+ (0.9v+g)+3.5 v = velocity in meters/min and G+grade.

For this example I am going to put grade at 0.

Running at 200m/min would take you 50 min to run a 10K. Running at 225m/min will mean about a 44:30 10K.

VO2 for the 50 min 10k yields 2175 ml of O2 per kg, VO2 for the 44:30 yields a 2156 ml of O2 per kg

1 L of O2 = 5kcals. The difference is 19 ml of O2 per kg. Calorie difference is negligible.

The use of glycogen to fat is a factor of what system you're relying on in an individual race so the difference will be minimal between a 90 minute and 2 hour 15 half runner because they will be relying on pretty much the same system. In fact, the 90 minute runner will burn more glycogen as they are running closer to LT

Ignore the formula I posted above, I'm after making a complete arse of myself with that. It doesn't belong here in this discussion. Apologies!:o

I still stand by the last paragraph though.

DocQismyJesus

NetwerkErrer wrote: »

Here we go. Quick copy and paste as I'm not doing the math again.




The use of glycogen to fat is a factor of what system you're relying on in an individual race so the difference will be minimal between a 90 minute and 2 hour 15 half runner because they will be relying on pretty much the same system. In fact, the 90 minute runner will burn more glycogen as they are running closer to LT

Since LT is completely individual how can you make that assumption? I'm going to ignore all the maths here because I simply don't understand it.

I'm a pretty experienced runner and have been involved at lots of different levels in the sport- hence I'd rather work off my experience when making recommendations

Not a swipe at you btw NE just think often the hard science can over complicate things

demfad

adrian522 wrote: »

Would it be the case that a gel may be useful for slower runners? i.e if you are out there for more than 2 hours does it become a more physical benefit? I understand if you are running 90 mins for the half that there should be no need but I thought if you were running over 2 hours you could do with topping up on Carbs during the race?

I think it might would be useful physically for slower runners.

Just to explain:

The working muscles for running are made up of a load of individual muscle fibres. Each muscle fibre has a glycogen store. You tend to use these fibres in a certain order too.
What happens, is that muscle fibres use the local glycogen store and then their work is mostly done, the next fibres are activated, glycogen used and on we go. (it doesnt work exactly like that but thats close enough to get the idea).

If you're very well trained for the HM all the muscle fibres will be able to cope with the pace in turn until 21k without a slowing or fade.

If you're not well trained for the distance, the muscle fibres used later wont be as strong or have the endurance of the earlier ones, and pace will have to slow. You can picture the long worsening fade.

A gel puts glyogen mainly in the liver but some could be absorbed by the muscles particularly at 2hr race pace.

The brain uses the sugar from the liver so there's the obvious mental benefit already mentioned.

If some of the gel can be absorbed by the muscle then some glycogen will be replenished in the stronger fibres. This should have the effect of delaying the use of the weaker fibres somewhat and of pushing out that "fade" till later in the race.
Just as gels can be used to push out the wall in a marathon: they can also be used to push out a fade in a HM (and a marathon fade too).
This should improve race time.

Worth experimenting, but for physical benefits take one early in the race/experiment (takes time to be absorbed) and one later I guess.

For the mental benefits of liver sugar only, take one shortly before the mentally difficult point in the HM.

menoscemo

NetwerkErrer wrote: »

Ignore the formula I posted above, I'm after making a complete arse of myself with that. It doesn't belong here in this discussion. Apologies!:o

I still stand by the last paragraph though.

Does your formula take into account the fact that we all need approx 100 calaories per hour just to stay alive?

Like if a 2 hour marathoner and a 6hour marathoner do a marathon maybe they burn the same amount of calories moving the 26.2 miles but the 6 hour guy still needs 4 hours worth of Basal metabolic rate (BMR) calories too.

adrian522

Thanks all, very interesting discussion. My first half I did in 2:02:xx but didn't take any gel and looking back at my splits I faded badly in the last few miles.

My next half (one year later) I did take a gel but didn't feel I needed it but wanted practice taking one at pace. In this race my splits remained fairly consistent until the end. (1:42:xx was the finish time).

Not sure I'd take one during a half again but I'd probably carry one just in case!

NetwerkErrer

menoscemo wrote: »

Does your formula take into account the fact that we all need approx 100 calaories per hour just to stay alive?

Like if a 2 hour marathoner and a 6hour marathoner do a marathon maybe they burn the same amount of calories moving the 26.2 miles but the 6 hour guy still needs 4 hours worth of Basal metabolic rate (BMR) calories too.

Jaysus Meno. I admitted I was wrong. No need to twist the knife.

menoscemo

NetwerkErrer wrote: »

Jaysus Meno. I admitted I was wrong. No need to twist the knife.

Sorry man, I am lost

Edit: I hadn't seen that you'd removed the formula, I was actually asking a serious question (if slightly OT). Just curious as I don't understand the formula tbh...

NetwerkErrer

DocQismyJesus wrote: »

Since LT is completely individual how can you make that assumption? I'm going to ignore all the maths here because I simply don't understand it.

I'm a pretty experienced runner and have been involved at lots of different levels in the sport- hence I'd rather work off my experience when making recommendations

Not a swipe at you btw NE just think often the hard science can over complicate things

Fair point DQ. I guess the best thing is always going to be what suits you. What helps one person can hinder the other and vice versa and experience is always going to be the decider.

NetwerkErrer

menoscemo wrote: »

Sorry man, I am lost

Edit: I hadn't seen that you'd removed the formula, I was actually asking a serious question (if slightly OT). Just curious as I don't understand the formula tbh...

No hassle Meno! Thought as much.

Enduro

There is some interesting experiments supporting the "placebo" effect for gels. Have a google for the "pickle juice study", and how it can be related to the central governor theory. The interesting take away is that the performance effects of taking something like pickle juice (or sports drinks or similar) during exercise is so rapid that it cannot be due to digestion. Rather the brain (central governer) gets the message from your taste buds that fuel is on the way, and allows an increase in your body's perfromance in anticipation.

I'm not claiming its right or wrong, but its very interesting stuff to read about, and is based on experiments rather than just marketing. It would also suggest that loads of things would could have a similar effect (I seem to get similar benifits from fruit juice myself).

Ososlo

Oh great. I love a good Poll. Haven't had one for ages!

adrian522

Enduro wrote: »

There is some interesting experiments supporting the "placebo" effect for gels. Have a google for the "pickle juice study", and how it can be related to the central governor theory. The interesting take away is that the performance effects of taking something like pickle juice (or sports drinks or similar) during exercise is so rapid that it cannot be due to digestion. Rather the brain (central governer) gets the message from your taste buds that fuel is on the way, and allows an increase in your body's perfromance in anticipation.

I'm not claiming its right or wrong, but its very interesting stuff to read about, and is based on experiments rather than just marketing. It would also suggest that loads of things would could have a similar effect (I seem to get similar benifits from fruit juice myself).

I saw a study where people took a mouthful of sports drink and spat it out and they seemed to get a boost from that so obviously there is some mental element to it.

Clearlier

NetwerkErrer wrote: »

.

The use of glycogen to fat is a factor of what system you're relying on in an individual race so the difference will be minimal between a 90 minute and 2 hour 15 half runner because they will be relying on pretty much the same system. In fact, the 90 minute runner will burn more glycogen as they are running closer to LT

I've been out of the office so you could have deleted the whole maths thing completely and I would have been none the wiser!

I'd be open to the possibility that the above could be true for the same runner at the same level of fitness (excluding the BMR) but not for different runners (even at the same weight) nor even for the same runner at different levels of fitness (most importantly different running economy).

Quite simply the level of energy required to complete a half differs substantially from runner to runner and even within the same runner as their running economy goes up or down.

Jumping back to the piece I wrote that you were critiquing:

Clearlier wrote: »

Yes, the need for carbs is a function of how long you're running for, your ability to burn fat and the intensity of your running. The actual distance isn't really relevant except in determining the above.

I'm guessing that most of your critique is aimed at the 'burn fat' bit and I think that I'd be happy to leave it out as it's just confusing running economy and intensity.

If I rephrased it to "the need for carbs is a function of the time spent exercising and the intensity at which you're exercising" would we find agreement? My point about the distance not being important still stands which was the main thrust of what I was trying to say.

It's worth noting that the constant presence of the BMR means that runners who spend more time on their feet will have a need for more glycogen to complete the half.

I found this from the copyright owners/authors of the ACSM which does indicate that they realise that their measure isn't suitable for the real world.

The values in the Compendium do not estimate the energy cost of physical activity in individuals in ways that account for differences in body mass, adiposity, age, sex, efficiency of movement, geographic and environmental conditions in which the activities are performed. Thus, individual differences in energy expenditure for the same activity can be large and the true energy cost for an individual may or may not be close to the stated mean MET level as presented in the Compendium.

rainbow kirby

I'm pretty slow (last two halfs have been 2:01 finishes) and I generally wouldn't bother. Likelihood of my stomach doing a cartwheel as a result of taking one is a bit higher than I would like, for not an awful lot of benefit. Good breakfast in a reasonable time frame before it.

barryoneill50

Ososlo wrote: »

Oh great. I love a good Poll. Haven't had one for ages!

Jaysus A, i just spat my coffee out! I hope you are referring to the poll for this thread (: (: (:

Firedance

so there's no right or wrong just do what suits you, is the jist of where we are? I hated taking gels during marathon training and would consider not taking one when I do my next Half - I wonder though if I took one just before the start would my body use the sugar from the gel during the first part of the race and then use my glycogen stores thereafter or is that just a daft conclusion to come to?

menoscemo

Firedance wrote: »

so there's no right or wrong just do what suits you, is the jist of where we are? I hated taking gels during marathon training and would consider not taking one when I do my next Half - I wonder though if I took one just before the start would my body use the sugar from the gel during the first part of the race and then use my glycogen stores thereafter or is that just a daft conclusion to come to?

FWIW always take one just before a marathon starts for that reason.

I never take one for a half mind...

Firedance

menoscemo wrote: »

FWIW always take one just before a marathon starts for that reason.

I never take one for a half mind...

you'd be done and dusted before I get over the start line though meno