Leadville Trail Marathon Race Report

I'm a little nervous.  Its been awhile since I've run a race.  Like 6 months.  I haven't raced since Yankee Springs in January.  Now I'm standing on the starting line for the Leadville Trail Marathon, advertised to have 6,300 feet of gain over the 26 mile out and back course that is run entirely at over 10,000 feet above sea level.

Since I've been in Colorado I've had the opportunity to run with a bunch of great people, and most of them also signed up for the marathon.  We camped out in Leadville the night prior to the race after hanging around the cool little mountain town all day.

Then some guy fires off a shotgun and the stampede begins.  I'm a little amazed how hard everyone is running from the get-go.  Its faster than I'm used to.  And all uphill, errr maybe up mountain is more appropriate?  Soon I'm gasping for air.

A wee bit more climbing than I'm used to

I get a glimpse of the trail ahead.  More switch backs and more climbing.  Hmmm.  I'll slow down a touch I think.  I'm still gasping for air.  Damnit.

The first aid station is at about 4 miles into the race.  If you can't tell by looking at the elevation profile, its quite a climb up to that point.  I got some water and a gel and was on my way.  I think at this point I had settled into 25-30th place and was just trying to keep moving at a reasonable pace.  I typically try to move through aid stations as quickly as possible, and I continued this.  After cresting the Ball Mountain aid station and running quickly down the old mining roads, I started feeling a little better.  A combination of some downhill and scaling back the pace a little bit seemed to be paying dividends.  I occasionally looked around, and was greeted with gorgeous views of mountains and bright blue sky.

Survival mode

Coming through the aid station at the bottom of Mosquito pass, I really started feeling better.  Which is strange as you are still running at 10,000 feet above sea level.  I had passed a few more people, including some fellow retching and making awful noises in the bushes.  The climb up Mosquito starts off actually fairly gradual, and after a good amount of downhill to reach this point, I decided to run as much as I could.  

Since the race was an out and back, and the turn around point is at the top of this climb, the trail became rather crowded, as we had rejoined with the half marathoners who were both going up and going down the pass, depending on how far along they were.  Luckily we are on mining roads, and very rarely was there not enough room to maneuver around people.  It was kind of nice to have so much mental stimulation during the climb, which could be quite brutal.  I ran, then hiked, then ran, then hiked, alternating on shallow and steep grades and using my breathing as a guide as to when to settle into a pow-hike.  I actually really enjoyed this section as I felt I had a good grinding gear.

I passed several more marathoners, and had the pleasure of seeing the leaders come blitzing down the pass.  Then a marathoner passed me; he was running the whole damn climb, I couldn't help but admire his consistent climbing cadence.  

At the top of the pass I quickly filled my bottle (2:18), stepped on the timing mat, and when I was told that I was somewhere around 11th or 12th place, I decided to let it all go on the descent from Mosquito and see what happened from there.  

I'm a fairly good downhill runner, especially when I'm in the mood to take some chances.  I took some chances. This was evident as I passed 3-4 other marathoners on the descent.  Including the guy who had climbed so well up to the top of the pass.    Actually I still don't know how I didn't trip or fly off the edge of the mountain on this descent, but thankfully it all worked out.  The descent seemed to shake something loose in my GI track, and I was eagerly anticipating a port-a-potty stop at the aid station at the bottom of Mosquito.  Unfortunately I saw two children who were cheering on family go running into the bathrooms right as I ran up.  Crap (pun intended), I'm not waiting around for that.  I started to run up the deusche grade mining road to the top of Ball mountain and after a while my need for a reststop reseeded.  This is lucky as there is nothing but shrubbery and rocks above treeline.    

At this point, I've run enough races to know that the return trip was going to be interesting.  I'd been running at threshold for almost 3 hours, something I don't practice often.  

I kept eating and must have been feeling ok, because I kept reeling people in.  I would jog with them for a brief moment, chat and recover, then take off to catch the next person.

I kept up that routine for the rest of the race, except as I got towards the finish I tried to make my passes rather emphatic, especially on the downhills.  Trying to take care of myself until the very end of the race, I took an S!cap at about mile 21, as I noticed I was very satly, but had not yet started cramping.  

Speaking of downhill, for me, the last downhill was a sufferfest.  It was technical as there was plenty of loose rocks and washed out ruts on the mining road, slightly rolling, and lasted 3-4 miles.  I was putting everything I had into the first couple miles, but as I couldn't see anyone in the distance I let up on the pace for a tad and almost tripped over some rocks.  OK, lets finish this out strong I decided.  So I hammered my legs into oblivion running downhill at sub 6:30 pace.  I ignored my screaming feet as I had reached that point where you don't care about pain and just want it to be over.  

As I crossed the finish line, I was told I had finished 6th overall (500ish starters?) in a time of 4:05.  I was very pleased, I had been thinking anything under 4:30 would be very good, and hadn't dreamed of running 4:05 in a race with 6,000 feet of gain.  I didn't care as much about the overall placing as running a time that I was satisfied with.

Our whole group finished strong, and had a big grin (grimace?) on their face when they finished.  It was a great social environment with all the finishers being extremely friendly and congratulatory.  The race gave out coffee mugs as the finishers award, which I like (I think some ppl were disappointed and wanted a medal)  We hung around for the rest of the day and I rehydrated with Michelob Ultra (blech). 

Yeehaw

Liz and I both collecting our gold mining pans as age-group awards
 (we're the goofballs still in our running shorts)

Final thoughts:  While the trail race is a little expensive, it was well worth the $.  There were tons of goodies, plenty of food and beer, and a super enthusiastic environment.  While I don't usually like races with 1,000s of people, I do see the allure of larger events which really have a great environment.

Gear:  Scott T2 Kinabalu, The North Face Better than Naked shorts, Ultraspire Quantum belt, Ultimate Direction 20oz quickdraw water bottle.  

Food:  I don't remember?  Like 10 gels, and two bottles of sports drink?  No solid food.

Limiting GI Distress - Low FODMAP diets

Low FODMAP diets
Basic Application and Thoughts on Race Circumstances

Huh?  Fogmaps?  Frogmats?  Whaaa???

Up until recently, I had never heard of FODMAPs.  Then I went Paleo, and lots of new nutrition theory started sprouting up.  Honestly some is garbage and/or poorly interpreted research, but I actually think there is a lot of good scientific thought being put out there as well.  One of the term's I became most interested in, was the term FODMAP and how it was suggested to help people with digestive problems, specifically Irritable Bowel Syndrome (IBS) (1).  Then, I had the opportunity to attend an excellent seminar in our department on the topic.

I contacted the speaker afterwords, and she sent along a binder full of articles and links to another dozen studies focused on gastrointestinal health and the low-FODMAP diet (thanks Lexi!). 

So, with no further time wasting!

FODMAPs

Stands for:   Fermentable Oligosaccharides, Disaccharides, Monosaccharides and Polyols.
These are an otherwise unrelated group of carbohydrates that have a short chain length and can be fermented in the small intestine or colon and are thought to contribute to IBS in many individuals.

Examples of problematic short chain carbohydrates (2):

Oligosaccharides:  Fructo-oligosacchardies aka Fructans (found in wheat, rye, onions, artichokes) and galacto-oligosaccharides aka Galactans (found in legumes)
Disaccharides:  Lactose, maltose, sucrose (rare)
Monosaccharides:  Fructose
Polyols:  Sorbitol, mannitol, other –ol molecules

Short chain length is important to mention, as this is what makes these carbohydrates so readily fermented by the microbiome living within our gut.  What happens when we have fermentation in the gut?  Well, mostly gas, so you might start farting up a storm, but other, less amusing things happen too…

What I would suggest is that FODMAPs are mostly a component in foods that lead to gastrointestinal discomfort, whether it be diarrhea or bloating, both; these are totally not good for an ultrarunner (or anyone with a sensitive stomach).

Gastrointestinal discomfort

So what causes GI issues?  Well if you subscribe to the theories presented by researchers using low-FODMAP diets to treat patients, the etiology behind many of these GI issues is related the nervous system within the gut, known as the enteric nervous system (2,3).  Yeah, your intestines have a mind of their own.  The nerves that innervate the small and large intestine sense a variety of chemical signals as well as function as pressure sensors.  Persons with GI issues such as IBS are thought to suffer from over excessive activation of this nervous system (visceral hypersensitivity) which in turn communicates with the brain as well as activates smooth muscle within the intestine itself resulting in diarrhea and/or motility issues. 

Yet, in order for the gut to be hypersensitive, we must have some initial insult.  This is where FODMAPs and food chemicals are thought to play a role.  It is thought that the initial insult in many cases is something known as luminal distension.  This can lead to the feeling of pain and bloating, visible swelling of the abdomen, and also motility changes (3).  Based on this hypothesis, a dietary intervention has been recently implemented (mostly in Australia it seems) in order to minimize luminal distension. 

Luminal distension is though to be the result of mostly gas and fluid build up in the large intestine.  Gas is mostly a product of excessive fermentation in the colon and possibly the distal small intestine if the person has overgrowth of colonic bacteria (3).  The majority of fluids are normally absorbed  in the small intestine so that the feces is not too watery.  However, an excessive concentration of these small molecules results in poor absorption during transit through the small intestine; then they will pull water with them into the colon, resulting in luminal distension, even in normally healthy persons without hypersensitivity (3, 4). 

How to FODMAPs play into this all?  Well, diets high in FODMAPs provide large amounts of fermentable molecules to hungry bacteria in the colon and/or result in excessive fluid being pulled into the colon due to the osmotic influence of unabsorbed molecules such as polyols (3, 5).  In order to describe diets that are high or low in FODMAPs, foods have been analyzed and categorized for the various FODMAPs they contain (Table 1).    

Table 1:  Foods high in FODMAPs and alternative food choices.  Adapted from (5)

How does one approach this intervention if they feel it might be beneficial for them?  Well, I’m not an expert in this field, nor a dietitian, but what I have read suggests removing all FODMAPs from the diet and slowly reintroducing specific groups or foods and seeing if you are hypersensitive to these foods.  While some may find that they are sensitive to a wide range of FODMAPs others are only sensitive to a few select molecules.  Interestingly, this concept is already in practice and many do not realize it!  Hypolactasia (aka lactose intolerance) results in gastrointestinal discomfort including bloating, gas and diarrhea, thus people who suspect they suffer from this condition avoid consuming foods high in lactose.  Lactose is an excellent example because it highlights a very important issue concerning regulation of FODMAPs in ones diet:  individual sensitivity. 

Another case in which this is evident is the absorption pattern of fructose.  There seems to be a large range in peoples ability to absorb fructose, probably regulated by a genetic component (6).  Furthermore, the concentration of free fructose is the major contributor to fructose malabsorption as its absorption rate is determined by the ratio of glucose:fructose.  If fructose is consumed in concert with glucose, for example as  sucrose (a disaccharide containing both a molecule of glucose and a molecule of fructose), it is unlikely to cause GI symptoms, however, if one was to consume the same caloric quantity of pure free fructose, they would be more likely to develop GI symptoms.  

Are low FODMAP diets effective?

The short answer:  YES.  In people with IBS, low FODMAP diets have been shown to be extremely effective in reducing symptoms and discomfort, while re-introduction of FODMAPs usually results in the onset of new symptoms (3).  So if you’re a person with IBS this may be a dietary change that you want to consider.

FODMAPs and Running

I could have titled this section “Low FODMAP diets for the runs” but that would have been too obvious.  

How can a low FODMAP diet be beneficial for you as a runner?  Well if you have IBS, the application is pretty clear.  Those suffering from gastrointestinal symptoms are found to have changes in mood and fatigue levels after removing FODMAPs from their diets not to mention the fact that IBS induced diarrhea and gastrointestinal inflammation results in poor nutrient absorption and dehydration.  

Beyond treating IBS with a low FODMAP diet, to me, the application seems that this dietary pattern may be useful on a day to day basis when thinking about what to have for a snack before a run.  I’ve often heard it recommended avoiding foods containing too much fiber before going for a run, while lactose containing products are also often avoided.  

You know what I mean

While a low FODMAPs diet does not necessarily eliminate fiber from the pre-run snack, there is considerable benefit to limiting the amount of fermentable carbohydrates from the pre-run snack, both for you and your running partner.  Furthermore, foods containing polyols and other osmotically active FODMAPs likely contribute to increased gastric motility, a problem to which runners are particularly susceptible (7).   

In my opinion, the most important application of a low FODMAP diet is using this dietary pattern to make food choices the day before and even during a big race.  No one likes to deal with gastrointestinal issues while running 50 or 100 miles or a marathon.  Racing in particular stands out; people who normally do not have sensitive stomachs may notice an increase in gastrointestinal issues at higher effort levels (8).  Furthermore, dehydration due to diarrhea could put ones chances at finishing a race in severe jepordy.  I also think most race day (or week) nutrition strategies are also good strategies to implement when preparing for long runs and trying a low FODMAP diet several days before and up to a long run or race has the potential to be very beneficial to runners.  I should point out that the typical (although often innappriate) carbohydrate loading process involves eating a massive amount of pasta the night before a race.  If you look at table 1 you will notice that consumption of wheat products, especially large amounts, results in a large intake of fructans, thus many runners maybe be giving themselves a large dose of FODMAPs the night before an important race.  By avoiding these foods, keeping portion size in mind, and experimenting to find what works for them, some people might find some success with this dietary approach.  

Lastly, I should point out that many of the foods described above contain not only FODMAPs but other potentially irritating food components and chemicals such as gluten, salicylates, and allergens such as wheat, soy, milk proteins, amines and glutamates, as well as food additives such as benzoates, sulfites, and nitrates.  But seriously, that is an entire new can of worms.  Furthermore, gastrointestinal motility is under the control of multiple physiological systems, and can also be stimulated by caffeine and nicotine, something to keep in mind when trying to figure out why you spent 30 minutes hiding behind a tree at your last race.

Considerations

Low FODMAP diets are rather restrictive and may influence dietary quality depending on an individuals sensitivity.  Furthermore, many FODMAPs actually serve as prebiotics, thus by restricting these food components over the long term, one might change their micobiome.  If there is a reduction in fiber consumption due to the low FODMAP diet, this may influence ones risk of colorectal cancer and this should be taken into consideration.  While this dietary pattern has the potential to significantly improve the quality of life for those suffering from IBS, it may not be appropriate for everyone.  It should be kept in mind that this type of diet has application for runners, but that it might not be the overall healthiest way of eating, merely a tool.  I think you will start to hear more about this type of diet (if you haven't already) as it makes its way into the USA from Australia and abroad.  

Works Cited

1.         Ong DK, Mitchell SB, Barrett JS, Shepherd SJ, Irving PM, Biesiekierski JR, Smith S, Gibson PR, Muir JG. Manipulation of dietary short chain carbohydrates alters the pattern of gas production and genesis of symptoms in irritable bowel syndrome. J Gastroenterol Hepatol.  Aug;25:1366-73.

2.         Barrett JS, Gibson PR. Fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs) and nonallergic food intolerance: FODMAPs or food chemicals? Therap Adv Gastroenterol.  Jul;5:261-8.

3.         Gibson PR, Shepherd SJ. Food choice as a key management strategy for functional gastrointestinal symptoms. Am J Gastroenterol.  May;107:657-66; quiz 67.

4.         Clausen MR, Jorgensen J, Mortensen PB. Comparison of diarrhea induced by ingestion of fructooligosaccharide Idolax and disaccharide lactulose: role of osmolarity versus fermentation of malabsorbed carbohydrate. Dig Dis Sci. 1998 Dec;43:2696-707.

5.         Gibson PR, Shepherd SJ. Evidence-based dietary management of functional gastrointestinal symptoms: The FODMAP approach. J Gastroenterol Hepatol.  Feb;25:252-8.

6.         Barrett JS, Irving PM, Shepherd SJ, Muir JG, Gibson PR. Comparison of the prevalence of fructose and lactose malabsorption across chronic intestinal disorders. Aliment Pharmacol Ther. 2009 Jul 1;30:165-74.

7.         Rehrer NJ, Brouns F, Beckers EJ, Frey WO, Villiger B, Riddoch CJ, Menheere PP, Saris WH. Physiological changes and gastro-intestinal symptoms as a result of ultra-endurance running. Eur J Appl Physiol Occup Physiol. 1992;64:1-8.

8.         de Oliveira EP, Burini RC. The impact of physical exercise on the gastrointestinal tract. Curr Opin Clin Nutr Metab Care. 2009 Sep;12:533-8.

Tecumseh Double Trail Marathon

I put my graphic design skills to work

TTDM.

I'd never run the Tecumseh Trail marathon before.  If I had, I'm not sure I would have agreed to run the course in reverse the night before, per Scott Breeden's brilliant suggestion.  I've run in Southern Indiana before, and I never cease to be amazed by the plethora of excellent trails the area has to offer.  The hills are also much larger than what we have available anywhere near where I live.  If you want to check out what the area has to offer, you can read Scott's article here.

Great idea Ryan.  Also, notice the nice minivan/station wagon hybrid in the background

Sometimes I like to get a little stupid.  And luckily, I have friends who think the same way.  Scott asked around, and before I knew it, he had found two other saps to go for the TTDM with us.  We all met at the campground in Morgan Monroe State Forest, where race started the next morning (Saturday).  Then, Kevin, Ryan, Scott and I all hoped in the Toeriffica and drove to Yellowwood, where the race would finish (Saturday).  After nearly driving off the road multiple times, I finally got us there safely.  We proceeded to each take a pull of paleo-style buffalo whiskey in order to provide some analgesic effects. And we were off.

Ryan, Kevin, and I enjoying a beautiful day

I should point out that it was also nearing 60 degrees, and soon we were all warm and had to adjust our layers.  The first 45 minutes or so flew by, we were moving at a good clip, and I had noted to Ryan Case at least once that the hills were rather large.

Anyways, we ran, and ran some more, the mood was light, energy seemed good, and I was running the hills fairly well (at least for me).  We had water stashed at mile 13, right at the bottom of Indian Hill, and if you've never run down Indian Hill, its really freakin steep.  After bombing down it, I realized I'd have to go up it tomorrow, and knew it was going to be fun.

Indian Hill Bombing

I think someone farted

mtn bike gloves for $5 are good for grabbing trees

We continued along our marry way, dodging dogs and hunters, until we finished.  Upon reaching the campground where our tents were set up, a muscle in my left leg notted up into a nasty charlie horse, and from then on it felt as if I had a deep tissue bruise.  Definitely a new feeling, I've never had that happen before.  I blame it on only drinking 2 bottles of water for the 4 hour run.



We refueled with Mexican food, met up with more friends, then Scott and I screwed around in the woods, foraging for firewood and falling down ravines (that part was mostly me).  Before I knew it, it was 1am, and time to crash for the night.  Slept pretty well in my tent, and then it was race morning.  The first thing I noticed when I woke up was a big knot in my leg from where the cramp had been the previous day.  Not much to do but run on it.

TTDM day 1 a success

I can't emphasize how nice it was to sleep at the race start, as there was havoc in the shuttle system, one bus broke down, another one tried to run over a car (the race ended up starting 45 minutes late).  I found some friends, said hi, peed in some bushes, then stood around anxiously awaiting the start.

We started, and half of us ran down the road, while the other half cut across the grass and ended up ahead of us.  Interesting...

The first mile ticked by in 6:45, then another 6:45, and the 3rd mile?  You guessed it, 6:45.  I thought, oh crap at this effort levels im going to bonk, and I could still see Scott Breeden, which should have been the first sign I was going to hard, but then we hit the hills and Scott was gone.  My legs had felt strong climbing the previous day, so it should only be expected that they would be flat and dead on the inclines on race day.  So I tried to back down to a good pace, and ran with some guys Scott knew from Bloomington, and still felt like it was an unsustainable effort.  Josh Wopata was still near at this point, so we shared some laughs and I tried not to think about the fact that I was getting roasted on the uphills.

Sooner rather than later, Josh scooted away, I fell down, and I started to question my goal.  What was my goal?   Oh yeah, to finish.  I figured I could at least do that.

Up direction

Mile 12 came and went, then mile 13 at 1:45 into the race, and this time we had to go up not down Indian Hill.  It was as steep as I remembered from yesterday.  However, my legs were starting to come around, I was a little suprised I wasn't feeling bonky despite the early pace, and I felt confident that I had settled into a effort that I could maintain for hours.  I started the race with two scoops of roctaine powder in my water bottle.  I figured at the high intensity I would shoot for 150 calories an hour or so and continued to fuel at this rate.  I never had any stomach trouble and just ate gels and drank water after my Roctaine bottle ran out.

Around mile 16 I started to really feel good.  Only 10 miles left, and I feel this good???  I still couldnt believe I wasn't hitting bonk city running between 7:30-8:30 miles on trail in this hilly woods.

I guess my last two races had been 100 milers and I've forgotten that you can run hard at the end of shorter stuff.  Thats great.  I slowly worked my way up the field.  I think around mile 13 I was in 10th or 11th, now by mile 18 I was in 6th or 7th.    

I pushed hard when I saw Josh up ahead.  He had slowed a little, and I was moving well, so I said hi and kept moving.  He has done this to me numerous times in races so I had little remorse about not slowing to run with him.  I picked off a few more people, until I saw Scott's friends from Bloomington, probably around mile 25.  Usually if you are running hard enough to see someone you haven't seen all day, you know they're probably blown and you can catch them easily.  This guy...  Not so much.  I think hearing my panting behind him really woke him up, and he floated up a series of switch backs.  I dug deep, went deep to the well to try to match his effort, and came up with nothing.

Almost done

A couple wobbly running steps later, I pow hiked the remaining steep portions of the switchbacks and ran as soon as I reached douche' grade, but it was to no avail, 4th place was outtro.  We came into a long road section and I could see 4th and 3rd place about 1/4 mile ahead of me.  With only a 1/2 mile to go, I smiled, laughed a little bit and ran it in.  What a day.  Scott was already finished and was hanging out with Becky and Rebecca, other members of our crew; cheering and waiting for everyone to come in.  I asked Scott if he got the W, he said yes, which gets a thumbs up from me.

Scott posing for the camera

Finishing holding hands - how cute

Ended up 5th overall, in 3:26, which means I negative split the race, and funny because I've run slower road marathons...  I think it might have had something to do with the generous downhill sections towards the end, but I'm going to pretend it was my excellent pacing.  I think everyone had a great time - Fellow michiganders Ryan and Alaina Case also participated in our pre-race shinanigans, and then crushed it the following day (Alaina was 3rd OA woman in her first trail marathon!).  I fear if those two feed off each other and really train hard, soon I'll be getting Case'd.  Kevin Kearney, the other member of our stupid adventure finished with a strong kick, beating out whoever he had been running in with, and although I'd just met him, he seemed to always be in a good mood, making for a good running buddy.

Tecumseh is challenging, but beautiful.  Friday we ran the up direction, while Saturday we had a net downhill run.  We had great weather, like 60s and sunny, and the creekbeds were relatively dry - I can see them being difficult to maneuver if there had been flowing water.  According to my Garmin the up direction (Yellowwood to Morgan Monroe) has 3400 gain and 2800 decent, with the opposite being true for the actual race.  This is slightly less than advertised, but its still a lot for a marathon.  It felt more like the advertised numbers of 3500 ascent and 4000 decent, but who knows (or cares). 

Comments on paleo and the run.  For breakfast I had a banana with a ton of cashew butter, and followed the fueling plan I described above.  I'm still very interested in the fact that I didn't bonk.  Personally, I don't feel like I have any business running that fast of a trail marathon, especially running one the previous day.  The previous day I did the entire 26 on just 2 gels, which is on the low end of things.  I also felt like I got more of a kick out of the gels than I used to.  This was the first race I've run since going paleo, and I think that at lactic threshold, I am metabolizing more fat than I used to, allowing me to run longer at a higher heart rate or intensity without bonking.  Just a thought, but it would be pretty cool if that was the case.

Amino Acid Supplements

Amino Acid Supplements
Generally speaking, high dose amino acid supplements, utilizing pure amino acid sources.  While a chicken breast, or handful of peanuts may contain similar amounts of some of these amino acids, getting them in a proper ratio is very important (from what I've been told by experts in this field).  There is a strong body of evidence that BCAA (leucine, valine, isoleucine) are metabolized by skeletal muscle in order to meet increased energy demands during exercise.  BCAAs may also participate in inhibiting central nervous system fatigue (mental tiredness).

 I still don't know what dosage of amino acids is the best to use for exercise, but generally you see between 1-5 mg as a general amount of mixed or pure amino acid.  5 mg is a lot!  Remember, more is NOT always better, especially because it is important to get the proper ratios.

Other amino acids such as alpha-ketoglutarate, glutamine, ornithine, and taurine have more speculative roles that are perhaps less proven/researched.

I like that they are very clear as to what is in this supplement

Vespa is popular, but whats the amino acid breakdown/profile?

 

There exists evidence that by encouraging intramuscular carnosine synthesis beta-alanine supplementation results in lactic acid buffering within the muscle cells and perhaps increasing VO2 max under certain test conditions.  Generally thought to be more important for sprint or anaerobic workouts that generate a lot of lactic acid, recent evidence suggests there may also be some benefit for endurance athletes.  This particular supplement could have its very own blog.