Salomon Speedcross 3 Review

SC3 left SC2 right

On my second pair of SC3s, I did a little old fashion cobbler work and lowered the heel drop to 5 or 6mm:  Reduced Heel SC3s

Had these for a while.  Been meaning to post a review, but finally have put in enough miles that I feel I can give an accurate take on this shoe.  First, my experience with Salomon shoes - I really like the products put out by Salomon.  Yes, they are a little bit pricier, but man these are great pieces of well built gear.  I have run in the Speedcross 2, Fellcross, and now Speedcross 3.  The Fellcross has been my workhorse for most of the summer as well as a racing shoe.  The Speedcrosses are my bombproof rugged trail busters.  Maybe by some peoples standards this shoe is not beefy enough, but for me, someone who spends most of my time in shoes under 9oz the Speedcross 3 feels like a tank.

Compared to the SC2, the SC3's graphics have been updated.  The salomon racing rainbow has been elongated to cover the entire tongue, and some interesting new color schemes have been released.  I went with the all black shoes, because my size in the canary/gun metal were sold out.  Also changed on upper was the toe bumper.  I never had a problem with the SC2 bumper, and I havent had any problems with the SC3 bumper so I guess its all good.  Of course they use Salomon quick-lace technology, with a slightly updated tightening mechanism.

SC3 on the left Fellcross on the right

The cushion is the LT lightweight muscle cushion, which can also be found in the Fellcross.  There is plenty of cushion in the SC3, although they didnt feel as "soft" as my SC2s, I am not sure if this is because of less miles on the SC3 (~150) compared to the SC2 (~500).  A huge change is the heel to toe drop, which according to Salomon and runningwarehouse.com is 9mm.  Its still a significant amount of heel, but lower than the 12mm found on the SC2, I want a 6mm drop SC!!!!  I appreciate Salomon lowering the heel on this shoe, but really wish they had fully committed to making this shoe more midfoot strike friendly.  Unlike the Fellcross which has a 4mm drop, the SC3 feels like it still encourages a significant amount of heel striking.  This was obvious in the SC2, and maybe feels a little less encouraged in the SC3.  During Oil Creek, I was feeling great on the downhills until about mile 70 when my quads started to feel abused.  I had just changed into the SC3s, now I am not sure if it was just time for my quads to hurt, or if something about my downhill running form changed in the SC3s, but it is worth mentioning to anyone reading this (so no one...).

I think the two most significant changes I noticed were the lack of pronation control in the SC3 and a change to the lug pattern.  Being a neutral runner I appreciated the lack of pronation control, however I found both the SC2 and SC3 fairly easy to roll an ankle in.  I think this is due to the narrow footprint of the shoe as well as being fairly high off the ground.

The foam under the arch of the SC3 (left) is not nearly as built up as it is in the SC2 (right).  Removed pronation control

SC3 left SC2 right

In general, the SC3's lug pattern seems a little more thought out.  Its good to see Salomon improving on current designs.  The lugs are more carefully placed in the heel and toes in order to give optimum traction on parts of your foot with high levels of contact with the ground.  Such as the heel for downhills.  If you can see it in the photo, I have warn down the lugs on my SC2 in the heels, while on the SC3 they are heavily reinforced to keep them from getting abused by being connected to lugs that are directly in front of them.  This definitely was noticeable for me, and I felt much more control on steep downs when braking from the heel than I did in the SC2.  This feature or design can also be found on the Fellcross.

A quick comparison to the Fellcross.  These shoes (SC3) are more protective, less flexible and a narrower fit.  I think they are more comfortable on very rocky terrain as there is more push through protection and the larger lugs provide more protection.  However, the sizing doesn't seem to be the same, as I loved my size 10.5 in the Fellcross, but feel claustrophobic in the 10.5 SC3s (They are better after removing the insoles) and if I have a little extra $ before the MT110s are released I might grab a size 11 SC3.  Neither shoe breathes particularly well, but I am excited to use both as winter shoes, I think the SC3 will see a little more work as it seems beefer.

SC3 top Fellcross bottom.  The Fellcross is wider both in the toebox and in the ankle collar

Overall I am pleased with the SC3.  It will be a shoe that I may use when my feet are feeling particularly beat up, during a later part of a race or maybe on back to back runs or difficult two a days.  The traction is fantastic (did I mention I like lugged shoes?), and Salomon is headed in the right direction by releasing the 4mm drop Fellcross and lowering the SC3 to 9mm.  The biggest downfalls of the SC3 in my opinion, is that the toebox is too narrow and not tall enough and the sizing was difficult and not consistent with the SC2 (my 10.5s are perfect).

Hope this helps.  If there are any unanswered questions, let me know.

Looking for motivation

I just wanted to share some of my favorite youtube vids that give me great motivation and get me excited about this sport.  Most people don't understand why anyone would run an ultra, let alone a 100.  If you've never ran an ultra, or trail race for that matter, you may never understand why we do this.  Maybe these vids will help.  And if you have ran an ultra, you know why these vids are so special.  I hope these help provide some excitement for all my friends with big 100's coming up this November.  I will post several vids here, and more in a later post.  Enjoy!

 

Brooks Pure$hit

Ok so maybe the title is a little dramatic.  I got a pair of these almost immediately after they were released and was overall very excited about a 4mm heel to toe drop trail shoe with input from ultrarunning legend Scott Jurek.  As soon as I got these shoes I thought - if I wanted to look this ridiculous I would have bought Hokas.  Several clown shoe comments later I was out the door for my first road to trail run in them.
     One of the first things I noticed was that when I was lacing them up I couldn't get them as snug around my foot as I would have liked.  I have wide feet, but they are not very tall (does that make sense?) and found myself lacing the shoes up as tight as I could in order to try to secure my mid-foot. This made the useless "nav-band" seem even more useless as it floated about with absolutely no tension.  They also seemed to be wayyy to long in my normal 10.5.  I thought it wouldnt be an issue and might be nice to not bump my toes.

Photo - Therunnersvibe.com

     Standing still I could feel the "footpod" underneath my midfoot and thought the shoe had a nice rocker feel.  It was strange, but I had read on irunfar.com that the footpod wasn't noticeable once you start running.  So I started running.  Once I hit the trails I immediately noticed the great traction.  This was one of the things that had excited me about these shoes - I love lugged outsoles.  The puregrit really bit in to the ground and I found myself happy with the amount of protection and cushion that the bio-go material provided.  They kind of reminded me of my old cascadia IV with the amount of cushion and protection.  Surprising for a "minimalist" type shoe.
      As I was running in these shoes I could not no matter how many times I retied my shoes or tried different size socks, get my heel to lock down.  Brookes didn't include the extra eyelet on these shoes, perhaps thinking their "nav-bad" would do the trick.  It did not.  I never noticed any dramatic changes from the split toe design so I am going to go ahead and say it - Gimmick.  Same with the nav-bad - Gimmick (how did wear testers not let Brookes know about this?).  And the foot-pod, well it does let you know where you are landing, but I just never got comfortable with it so...  Gimmick.
    The shoe did a nice job of encouraging a midfoot landing, and had just the right amount of flex, but I have to say I am not a fan of the foot-pod.  I know I have a slightly different strike point with my right foot than I do with my left foot, and the foot-pod continually reminded me of this, which began to annoy me to all ends.  I also started to worry about the pressure from the pod on my right foot would aggravate an old case of PF.  This is where my experience was so sour I called it quits with this shoe and it has since been shelved. 
     Overall, this shoe has some kickass features, awesome outsole, super comfy interior, and it was a great concept (low to the ground cushion performance trail shoe), but poorly executed with some gimmicky feeling additions.  I think Brookes should have tried not to be so cute and just made a shoe to compete with the Rogue Racer, MT101/110, Peregrine, etc.  Without the unnecesarys this shoe would have rocked (no pun intended).

Oil Creek 100 Race Recap

Rolling into town.  Photo by Ryan Hagy

I cant think of any way to start this recap, except to say this race is awesome.   I guess because Oil Creek is only in its 3rd year, somehow I figured it would somehow be plagued with small logistical problems that take several years to iron out.  Boy was I wrong.

I am just going to dive right in.  Friday morning, my crew chief Hagy and I stopped at Whole Foods, grabbed some tastey looking foods and hit the road.  I picked Pad Thai from the hot bar, and along with jelly beans, a couple bagels and muffins, I had a carbolicious day.  As we came closer and closer to Titusville, PA, the roads began to move from gently rolling, to long steady uphills and downhills, something I rarely get to experience in Michigan.  And then we were there, Titusville Pennsylvania, birth place of the oil industry.  The terrain seemed foreign with wide valleys, fast flowing rivers, and roads winding between tall hills.

Hagy and I quickly set up our tent, securing a spot in the middle school parking lot, across from the race headquarters (Titusville Middle school).  We had time to kill before packet pickup started, and decided it would be wise to go check out the route to the Petroleum Center aid station, the only crew access point away from the middle school.   This ended up being a smart move, as it was really the only time I was able to take in the scenery without feeling a sense of urgency.

Old bridge

Hagy looking cool while we were surveying the area

The road to Petroleum Center aid was...  treacherous to say the least, funny thing was this was the only aid station the race director was comfortable having people drive to.  After checking out the sites we stopped by packet pickup, where I noticed my bib # was 117 (17 is my lucky #) and decided this boded well for the future.  Walking around the school I had the chance to talk to Jill Perry, a badass montrail athlete who was very enthusiastic about there new shoes.  I had the chance to get my hands on the Montrail Bajada - a shoe receiving glowing reviews from irunfar.com editor, Bryon Powell.  Expecting the small lugs found on the Rogue Racer, I was pleasantly surprised by the Bajada's heavy lugs.

I had packed my two drop bags during the week before the race.  Included food- a wide variety of gels, a bunch of clif shot bloks, red bull, ensure, and salt and vinegar chips.  I also packed fresh socks and shoes.  Last minute I gave Ryan some stuff to keep with him that could be useful, but really only for emergencies.  I figured everything essential needed to be in my drop bags.


It took a while to fall asleep, Jason stopped by at about 10:00pm, he made it to the race safely, but had to push a deer out of the road with his car.  Im glad he didnt get hurt.  Ryan had little trouble passing out, I was jealous.

I woke up at about 3:00am, ate a bagel and a couple tortillas with nutella.  I felt stuffed.  To stay warm I headed to the middle school where someone who worked at the school had made coffee for several early risers.  Score, I got a nice warm cup of coffee and relaxed for a couple minutes.  At about 4, I headed back out to the tent and put on my clothes, and dropped my drop bags.  It was a 5am start so I kept my headlamp and was ready for action.  I was excited to use my new fenix HP11 to light up the trails, but about 10 minutes before the race start, I noticed it wouldnt turn on!!!  Freaked out, I ran outside and luckily they hadnt taken my drop bag to Petroleum Center aid, and I grabbed my backup lamp.  Shit, this lamp wasnt nearly as bright as my fenix.  Disappointed, I had no choice but to suck it up and proceed.

Cool start photo by Ryan Hagy

I asked Hagy to take a look at the lamp, but figured the review I had read online suggesting it was too fragile was right and that I had accidentally broken it already.  This frenzy killed anytime I had to get nervous before the race start, and before I knew it, Tom Jennings said "go" and we were off.  I settled into a pace that I thought was appropriate and chatted with Jason and another fellow who was running his 42nd 100 miler (I think?)!!!  Keith Straw is awesome, a 2010 Grand Slamer, OC was his 10th 100 of the year, and all around friendly guy, I wanted to run with him and just soak in some knowledge.  The pace everyone was running at was perfect for me as I was watching my heart rate carefully and wanted to run conservatively for the first 50k-50 miles.

Keith Straw leading our conga line

 Running along, we had some nice conversations getting to know everyone in our conga line as we cruised our way to Petroleum Center.  Arrived at PC1 (1st time through) in 2:40 and change.  Knowing this was almost halfway through the 50k I felt like I may have been moving a little too fast (although a lot of people were ahead of me), but wanted to get in and out of the aid station.  Ryan had fresh bottles of water and amino waiting for me, so I grabbed them and then started the long climb up Heisman Hill.  I said, Hi to Kieth, but was power hiking strong (which I was very pleased with) and passed him as I moved up the hill.  The next sections kinda flew by, running alone most of the time I just settled into a rythm, focused on eating, drinking and enjoying the awesome sights and sounds.  There were a few more serious climbs on the backside of the 50k, which was definitely the slower half.  I came into the Titusville Middle School aid feeling great at almost exactly 6 hours.  Again Hagy had fresh bottles waiting for me and I refilled my pockets with gels and shot bloks and hit the trail.

We only had to run this 3x

I dont remember much of the 1st half of this loop.  I was feeling OK, but not as good as I had earlier.  Somewhere along the way I noticed I was heating up pretty fast and sweating more than I was used to.  Nice hot (75-80 degree) fall day.  I took off my shirt, at the risk of looking silly with my nipples duct taped, and occasionally splashed water on myself to keep cool.  I noticed I was getting thirsty more often and not drinking enough, and realized I hadn't peed in over an hour.  I immediately started pushing fluids and chugged a water bottle along with popping an Scap.  I maintained this attitude until PC2 and was feeling much better by the time I arrived.  I tossed my shirt (which I had been carrying in my waist band) into my drop bag, grabbed fresh water and more gels and immediately jumped back onto the trail.  Again, exactly 2:40 for this section.  Feeling much better once I was rehydrated, I maintained an aggressive power hike up the long steep climbs and soon found myself enjoying some smooth shallow descents, perfect for me and my thunder thighs.

Ashley Moyer making it look easy

Soon I ran up behind Ashley Moyer, a youngster (23) attempting her first 100.  She was looking smooth, and I was sick of running alone, so I asked her if she minded some company and chatted with her for a while.  Together we breezed past the 50 mile point and hit Aid#3 (mile 55ish).  I have a feeling Ashley is going to dominate some races in the future.  Alas, at this aid station, I lost my company as all I needed was water, and I quickly started up "Floking Hill" and "Rockefellers Revenge" some of the steeper climbs, while really enjoying the downhills. I did my best Killian Jornet impression, hands on knees, grunting up the steep stuff.

The last mile or so into the flat drake well loop is, in my opinion, one of the toughest sections of trail we ran all day.  Its downhill, but steep and technical, which really takes a toll on your quads and feet.  Then you dump out onto some pavement which added to my groaning foot discomfort.  Energy-wise I had been on top of my game, with little stomach issues, except some slight naseua when I think I over salted with Scaps too frequently.  I had been doing a great job of mixing up my fuel between gels, clif bloks and the occasional potato wedge, snickers, or twix bar.  This fueling strategy is now my go to, as I was averaging 250-350 calories per hour fairly comfortably.

Ok, Titusville Middle School Aid.  100k finished.  Again, this 50k loop clocked in at 6 hours (actually 5:59).   Knowing it would get dark soon, I dropped my bottles for a hydration pack, and even better, Hagy got my Fenix lamp to work!!!!!  This really had me pumped.  Turns out the 10 pack of new batteries I bought at Walmart were all duds - making me think my lamp was toast.  He put in some fresh batteries (awesome thing - they had batteries at the aid stations) and it was working again.  Here I made my only mistake all day. I changed out of shoes that were uncomfortable into my Speedcross 3s that I had added a high volume insole to a few days before and hadnt run in since.

Switching shoes and grabbing tunes before dark

I grabbed a slice of pizza, took a couple bites and stuffed the rest into my pocket for later :)  Armed with my 120 lumen headlamp and fresh socks and shoes I charged out to see if I could run another 6 hour loop.  I was hours ahead of my projected 24 hour goal.  Feeling pretty good for the hiking and running the flats, I quickly noticed that my toes were getting crushed on downhills. Not only that, but my gait changed slightly in these shoes and my quads started to ache on long descents.  Now I am not sure if this was because I was over 70 miles into the race or if it was because of the shoes.

Shoot, I left my sunglasses down there - will you go get them for me?

Doing a little more walking than I should have (I still need to get mentally tougher) I came noticed my pace slowing.  I finished off my pizza as well as a cup of chicken broth while power hiking switchback mtn.  It was dusk as I neared the top.  Then I heard a rustling in the woods, louder than a chipmunk.  I looked up, and there was a black bear standing about 100 feet off the trail, just looking at me.  Probably trying to figure out why I smelled so bad.  Not knowing what to do in this situation, but having read about Ellie Greenwood scaring away a bear at Western States, I raised my arms high, began shouting and carrying on.  The bear retreated, looking back at me, until I began making a racket again.  I proceeded down the trail as darkness set in.  From here on, anytime I heard anything in the woods I expected to see a bear, but thankfully did not. 

I came into PC for the 3rd time, but noticed I was at about 3 hours, 20 minutes slower than the previous loop.  Deciding my shoe choice was a terrible move, I put on a fresh pair of MTE101s I had put at PC just in case this exact scenario occurred.  It was here Hagy told me I was moving along better than many other runners.  That was all I needed to hear, and with a cup of Ramen left the aid station.  My feet were much happier as dusk ended and night set upon us.

Sadly, this sign is right.  At least I got 75 miles in first

The night was kind of uneventful.  I slowed down, partially because my quads blew up somewhere after mile 85, but I managed to get down the long last downhill section and run all the way back to the middle school.  Hagy was waiting - I sat down chugged a red bull, ate a cup of ramen, looked to Ryan, who indicated he was ready for his first pacing duty ever, in jeans and his 13 year old tennis shoes.  No worries, I wasnt moving very fast anyways.  7 mile victory loop here we come.  It was amazing to have company.  I had been running alone for almost 17 hours after separating from Jason and Kieth after about 2:40 into the race, and I think I proceeded to talk Hagy's ear off.

Somewhere on this section is the Boughton Acid Works, an old acid dumping ground, which was devoid of all vegetation and reeked of sulfer.  Kinda eerie to hike through at night.  Then we came to a giant suspension bridge over the major river the race travels around.  It swayed from side to side as we initially charged across.  I had to stop for a moment and take it all in.  Here I was in the middle of the woods, in the middle of the night, on the middle of a swaying bridge, having run over 90 miles and in 4th place.  I asked Hagy to turn off his headlamp for a minute and I did the same.  It only lasted a second, but I was flooded with positive vibes that can only come from doing what you love and conquering immense challenges.

Hill of truth about mile 4

We turned our lamps back on, climbed "The Hill of Truth" which was a long one, but nothing could stop me now.  Quietly I suffered the long downhill back to the road, and finally ran it in.  To aid station #4, which apparently was not the finish line.  After a brief celebration, I turned around and ran back to the actual finish at the back entrance to the middle school.  I found myself a chair and plopped down.  Ryan grabbed some warm clothes for me and I just sat there in a daze.  A PR of 20:52, almost 2 hours faster than Kettle. 

 

Come here foot, I want to take these socks off

All in all OC100 is a fantastic race.  Aid stations were well stocked, volunteers were super friendly and helpful.  Everyone was friendly and helpful for that matter.  The course is spectacular, old structures to look at, wildlife to scare, hills to climb, rocks to slip on, and pizza to eat.  Also we had hot showers available to us after the race (which I almost passed out butt naked in, be careful with hot water when you are exhausted).  I will be back.  Many thanks to Ryan Hagy for the company on the drive, being an excellent crew chief and pacer.  I have never had either of these things before, and I can see why people use them.  Pacers especially.  Ryan better be careful, he may end up being roped into more sleepless adventures.

Sub 22 hour 24k gold plated buckle - now I need a belt

Oil Creek Prerace Jitters

I always get nervous before a race.  Part of that nervous energy goes towards making my race kit, studying the different sections of the course and choosing different shoes.  Looking back at my training log, Ive put in more miles, more long runs, and longer runs than I did preparing for the Kettle Moraine 100 mile.  That being said, logging miles isnt everything.  I spent some time on the stairmaster last week, working on my steep power hiking skills, maybe that will help.  A huge portion of this race is going to be mental fortitude (for me anyways) and keeping my feet and stomach happy.  I think I have the stomach thing under control during a 50 miler - I am basically a garbage disposal who can run- but I am planning trying something slightly different at Oil Creek than Kettle.

Dont ask me how much this all cost

Having run a very happy Ice Age 50 mile 3 weeks before Kettle using soley gels as a fuel source, I figured I would just do the same for the 100 miles at KM.  Bad Toe.  I learned after bonking out kinda hard around mile 83 that I get super sick of gels after about 100k, and need to use more solid food.  After the race I spend some time reading peoples strategies for Western States, and noticed super fast veterans like Andy Jones-Wilkins eat mostly "solid" food for the first 50 and then switch over to gels.  This will be my approach for Oil Creek.  Ive been practicing eating clif bars, candy bars, chips, power bars, muffins, and PB&J sandwiches as I run the poto.  I hope to do something similar this weekend.  Solid food will consist of Honey Stinger waffles, Clif Bloks, Power Bars, Clif Roks, mini snikcers, and the occasional aid station food.  I am aiming for 300-400 calories an hour - yes this is a lot, yes I can eat this much, I hope I dont over/under do it as solid food is more difficult to track consumptionwise than gels. 


Onto my feet.  Those who know me well know that I have some pretty cool feet.  I was lucky enough to have some wicked surgeries on my left foot when I was in 6th grade, and as a consequence of damage to my growth plate, my 4th toe has not grown since.  Running shoes are hard to find for me.  One foot is wide and short, the other is long and skinny.  Blah blah blah.  Im gonna rock my new favorite shoe, the MTE101 (European version of the ever-so-popular MT101) for as long as I can, and switch over to my new Speedcross 3.  Being the self proclaimed shoe nerd that I am, I will also have my Fellcross, Mtn Masochist, Kinvara, and MT100s either in my car or in the drop bag.  Socks - drymax pro are the best socks in the world.  hands down.  period.  but if I need something softer, I will have some smartwools somewhere.

Yeah, I know, awesome

Notice the long scar on the 4th metatarsel

There is still some last minute planning to do.  Exactly which gels go into which drop bag.  Which socks to put where.  What shorts will I wear, etc.  These will be things that I think about over the next couple days.  Importantly, I made some humungous Banana Walnut muffins for Hagy, Jason, Chris, and anyone else I deem worthy of a delicious muffin.

I thought I would end this post with my mileage that I ran in preparation for the race (hopefully it will inspire some confidence).  **note**  this is probably not a wise amount of miles to run week to week, but hell, it makes me happy :)  If anyone is actually interested, I usually run 2x a day.  mostly a short 3-6 mile run in the morning/lunch time and then however long I can muster at night.  These daily total reflect both runs.

Month

Date

Miles

June	27	14
June	28	3.5
June	29	21
June	30	17
July	1	9
July	2	18
July	3	17

Week total - 99.5

July 4 July 5 13 July 6 14 July 7 15 July 8 July 9 31 July 10 9 Week total - 82
July 11 15 July 12 18 July 13 15 July 14 15 July 15 15 July 16 27 July 17 15
Week total - 120
July 18 15 July 19 15 July 20 15 July 21 0 July 22 22 July 23 12 July 24 29
Week total - 108
July 25 10 July 26 18 July 27 18 July 28 15 July 29 13 July 30 5 July 31 32 Week total - 111 August 1 August 2 18 August 3 18 August 4 20.5 August 5 15.5 August 6 36 August 7 18 Week total - 126 August 8 0 August 9 15 August 10 20.5 August 11 15 August 12 15 August 13 20 August 14 24.5 Week total - 110 August 15 16 August 16 16 August 17 17.5 August 18 13 August 19 15 August 20 15 August 21 12 Week total - 104.5 August 22 0 August 23 6 August 24 9 August 25 0 August 26 0 August 27 50 August 28 6 Week total - 71 August 29 10 August 30 12 August 31 0 September 1 18.5 September 2 12 September 3 13 September 4 23 Week total - 88.5 September 5 18 September 6 15 September 7 0 September 8 15 September 9 6 September 10 50 September 11 0 Week total - 104 September 12 6 September 13 12 September 14 15 September 15 18.5 September 16 19.5 September 17 29 September 18 20 Week total - 120 September 19 0 September 20 21 September 21 22 September 22 17.5 September 23 18 September 24 26 September 25 25.5 Week total - 130 September 26 13 September 27 11 September 28 12 September 29 14 September 30 11 October 1 13.5 October 2 13.5 Week total - 88

BCAA and the CNS Fatigue Hypothesis

An elegant hypothesis with limited laboratory support

(In my humble opinion)

            What is bonking I ask?  As participation in marathons, triathlons, and other endurance endeavors increases this question becomes more pertinent (a recent survey by Running USA suggested that over 500,000 people completed a 26.2 mile marathon in 2010, a 9.9% increase over the number in 2009).  Also known as exercising to exhaustion or “hitting the wall,” the idea of fatigue resulting in failure to maintain a desired pace that sets in late in a long event has been an interesting concept for nutritionist as well as exercise physiologists.  The short answer to the question is that we don’t know exactly what results in “bonking.” 

            The long answer is that this is probably the result of several metabolic changes resulting in fatigue.  While most acknowledge that muscle glycogen depletion and lactate accumulation contribute to peripheral fatigue, they do not fully explain the induction of fatigue during sub-maximal exercise such as endurance events or high altitude climbing (1).  One prevailing hypothesis is that exhaustion is regulated by the central nervous system (CNS). Peripheral biochemical changes that occur during exercise influence the CNS, resulting in failure to recruit more skeletal muscle and reduced performance.  One peripheral biochemical change resulting in CNS fatigue is hypoglycemia due to liver glycogen depletion.  In this respect, carbohydrate intake is thought to attenuate CNS fatigue by maintaining blood glucose levels (2).  Interestingly, another cause of CNS fatigue is thought to be increasing concentrations of serotonin or 5-hydroxy-tryptamine (5-HT) in the brain which is derived from the large neutral amino acid tryptophan.  The neurotransmitter 5-HT is known to play a role in sensory perception, depression, sleepiness and mood, making it a likely candidate for the CNS fatigue hypothesis (3).

            While BCAAs are metabolized by skeletal muscle during prolonged exercise, they also compete with free tryptophan for uptake across the blood brain barrier (BBB) by L-type amino acid transporters.  However, as endurance exercise continues, skeletal muscle increasingly oxidizes BCAAs, diminishing the plasma BCAA pool, which reduces competition with tryptophan for transport across the BBB (3).  A unique amino acid, tryptophan is the only amino acid that binds albumin in plasma (4).  Indeed, under normal circumstances, approximately 90% of plasma tryptophan is bound to albumin (3).  However, as muscle and liver glycogen stores are depleted, free fatty acids are released to support metabolic demands.  In turn, free fatty acids bind albumin, resulting in competition for binding sites on albumin with tryptophan (4).  This results in an increase in unbound tryptophan that can be transported across the BBB. 

            Thus it is hypothesized that by increasing BCAA consumption during endurance exercise one might be able to attenuate CNS fatigue by increasing competition with tryptophan for transport to the brain. Despite the elegant science behind this hypothesis, data regarding the efficacy of this approach appears to be limited.  A field trial reported increased mental performance in trained runners consuming BCAAs during a 30km competitive event (5).  Interestingly, this has not been replicated in well controlled laboratory conditions (6).  Similarly, consumption of an isocaloric solution containing BCAAs and carbohydrate did not influence the time to exhaustion in glycogen depleted cyclists compared to those consuming carbohydrate alone (7). 

One important caveat is that consumption of exogenous carbohydrates is a must for endurance athletes.  It has been shown that consumption of carbohydrates diminishes the release of free fatty acids, in turn influencing the amount of free tryptophan in plasma that results from prolonged exercise, possibly negating any benefit derived from BCAA consumption (8).  Furthermore, large doses of BCAAs can increase the ammonia concentration in plasma due to their metabolism resulting in the release of nitrogen, requiring buffering by TCA cycle intermediates, which could lead to early fatigue in working muscles (9).  It is entirely possible that by consuming BCAAs during exercise one is able to offset the effects of CNS fatigue, only to increase peripheral fatigue (9).  It is also important to point out that the hypothesis discussed in here does not take into account the role of BCAAs in supplementing skeletal muscle metabolism.  In summary, while combating CNS fatigue with BCAAs is certainly an intriguing nutritional intervention, there seems to be limited laboratory data supporting its efficacy.   

This leads me to share my feelings on laboratory science and the nature of ultra-endurance sports.  To me, it seems as though it is nearly impossible to replicate a true ultra event in the laboratory.  Whether it be due to ethical concerns, athletic desire, or simply lack of a truely difficult labortaory training environment, I feel it is hard to re-create the extreme conditions an ultrarunner might face.  Heat, alititude, mud, 15-16+ hours of running, sleep deprivation, hypothermia, all these are very difficult to recreate.  In this aspect when considering nutritional interventions for sport, I try very hard to fully grasp the science behind the supplement.  Nutrition, in particular can be masked by many variables, and in the end may only result in a 1% improvement which in the end may missed due to the insane number of variables that go into exercise performance.  Based on these observations, I look for what is called Biological Plausibility - does the supplement have a large amount of molecular and biochemical support, even if the observations on performance gains in humans or animal models are limited?   In the case of BCAA in limiting CNS fatigue, I think yes!

Works Cited

1.         Noakes TD, St Clair Gibson A, Lambert EV. From catastrophe to complexity: a novel model of integrative central neural regulation of effort and fatigue during exercise in humans: summary and conclusions. Br J Sports Med. 2005 Feb;39:120-4.

2.         Karelis AD, Smith JW, Passe DH, Peronnet F. Carbohydrate administration and exercise performance: what are the potential mechanisms involved? Sports Med.  Sep 1;40:747-63.

3.         Blomstrand E. A role for branched-chain amino acids in reducing central fatigue. J Nutr. 2006 Feb;136:544S-7S.

4.         Curzon G, Friedel J, Knott PJ. The effect of fatty acids on the binding of tryptophan to plasma protein. Nature. 1973 Mar 16;242:198-200.

5.         Hassmen P, Blomstrand E, Ekblom B, Newsholme EA. Branched-chain amino acid supplementation during 30-km competitive run: mood and cognitive performance. Nutrition. 1994 Sep-Oct;10:405-10.

6.         Cheuvront SN, Carter R, 3rd, Kolka MA, Lieberman HR, Kellogg MD, Sawka MN. Branched-chain amino acid supplementation and human performance when hypohydrated in the heat. J Appl Physiol. 2004 Oct;97:1275-82.

7.         van Hall G, Raaymakers JS, Saris WH, Wagenmakers AJ. Ingestion of branched-chain amino acids and tryptophan during sustained exercise in man: failure to affect performance. J Physiol. 1995 Aug 1;486 ( Pt 3):789-94.

8.         Blomstrand E, Moller K, Secher NH, Nybo L. Effect of carbohydrate ingestion on brain exchange of amino acids during sustained exercise in human subjects. Acta Physiol Scand. 2005 Nov;185:203-9.

9.         Davis JM, Alderson NL, Welsh RS. Serotonin and central nervous system fatigue: nutritional considerations. Am J Clin Nutr. 2000 Aug;72:573S-8S.