Nutrition is a pretty important part of ultra-running. Whilst you can get used to running without eating too much by becoming a more efficient fat burner, for races and for optimum performance you really need to stoke the fire as you go. In my training I tend to rely on fat-burning, largely because gels are frigging expensive, and I'm too cheap to buy them if I can help it. So I very rarely eat anything on my runs, even on my long (25-30ish miles) ones.
But even the most efficient fat-burner still needs carbs to function - "fat burns in a carbohydrate fire" I believe is the cliché that is bandied around. For this reason, I tend to use gels when I race, and will often make my way through a 100 miler predominantly on these, with the odd bit of fruit thrown in at the aid stations. I don't go too nuts; for instance I probably had 5 gels in 8 hours at the recent SDW50 - so about 1 every hour and a half. This works out fine for me, and gives me the energy I need to keep going, without causing major stomach-related issues or borderline diabetes.
Below is a little review of the two main brand of gels that I use - TORQ and GU. I don't really know the ins and outs of physiology and metabolism (I believe that the head-bone is connected to the arm-bone?), so I won't go too much into the "sciencey" side of things. The main thing that I care about is how they taste and how easy they are to eat while running. It's simply a way of getting energy into my face at the end of the day. Beyond that, I don't notice a huge difference between them; I know what I like and what works for me after a few years of trying various things out and failing miserably every now and then. I'll pretty much eat anything I'm given, but these are the ones that I will go for if given the choice.
GU are a mainly US brand of gels, but have gradually found their way over to the UK with specialist ultra running stores like the Ultra Marathon Running Store and Centurion Running Store making them readily available. Centurion were one of the main proponents of this since Race Director James Elson is a big fan of them (he ate about 75 of them in his first Western States 100 miler apparently).
The very first time I tried one of these was at the Likeys Brecon Beacons Ultra a few years ago, when I received a "vanilla bean" flavoured GU in my goody-bag. It was horrific! Sickly sweet and with the texture of wallpaper paste, I really wasn't a fan. Fast-forward to my first Centurion Running event, the Thames Path 100, and GU was all that was on the menu. But the more I had them, the more used to the slightly different texture I became, and for a while these became my go-to gel of choice.
How Do They Taste:
There are plenty of flavours available: strawberry & banana, salted caramel, chocolate outrage, mint chocolate (although they appear to have discontinued these), tri-berry, peanut butter, chocolate peanut butter, mandarin orange, lemon sublime, jet blackberry, vanilla bean, espresso love, vanilla bean, lemon sublime, and plain. A few of these (e.g. chocolate outrage, jet blackberry, espresso love) contain added caffeine, so are probably more suitable for later in the race when you need to try and keep yourself awake.
My personal favourites are the chocolate mint (goes great on ice cream), chocolate outrage, and strawberry and banana. I still don't like the vanilla bean flavour, and can only imagine what the plain flavour is like. I also find the mandarin orange a little artificial tasting, but the other fruity ones are very tasty.
What's In 'Em:
The main source of energy is a blend of maltodextrin and fructose. The idea is that the complex carbohydrate maltodextrin is easier and quicker to digest than simple carbs, and the ~4:1 ratio of maltodextrin with fructose is supposed to be the optimum combination ("scientists say"). You get about 100 calories per 32 g gel, along with added electrolytes, amino acids for muscle repair (whether these actually do anything while running rather than during recovery is debatable), and in some cases caffeine.
How Much Of A Faff Are They:
One of my main issues with gels is the faffiness of them, in particular the fact that they make you all sticky. And then you have to deal with the wrapper, usually shoving it in your pack where it will get sticky and 'oribble. Yuck! The fact that GUs are thicker, and more of a paste than the usual syrupy gels you get, is actually a real bonus. It takes a little bit of time to get used to the texture, but actually I much prefer this as the empty packets don't leak so badly. Having said that, in the heat you still get the same issues - eating a warm, gooey, chocolatey gel can result in you looking like a small child with it smeared all over your face.
The wrappers are pretty easy to open on the run, although the slightly wider gel packet makes it slightly more awkward to ensure that you squeeze everything out before shoving the not-quite-empty packet into your pocket. The tall thin packets of other gels are easier to roll toothpaste-style in order to ensure that you squeeze out every drop. But apparently this pack uses less material than other gels, so I guess it's better for the environment.
How Expensive Are They:
They run at about £1.50 each, but work out cheaper if you buy in bulk. You can purchase them in the UK from the UltraMarathon Running Store. That's about average I would say for these things.
As well as the regular gels, you can also buy the Roctane range of gels, which have the same carbohydrate content but more of the other stuff. And more is better I guess? I don't really think about it to be honest - I just grab whatever is available. They also do GU Brew, which is a carbohydrate and electrolyte replacement drink in tablet form. Stick a tablet in your water and it will dissolve like an Alka-Seltzer. The only issue with this is that it causes a build-up of gas in the bottle as you run, causing it to fizz when you open it for the first time. The first time this happened to me, the lid of my bottle almost popped off from the pressure! They also come in little pouches of powder which don't have this issue, but which are a little more faffy to deal with (and I find tend to be more than a single serving so you end up with half a pack left over to worry about while running). Also available are GU Chews, little bags of chewable sugar that give you an energy hit, but personally I find the gels easier to deal with whilst running.
I first heard of TORQ last year when they sponsored a Trail Running Team with a difference; aiming to sponsor normal everyday runners rather than elites. I had never really heard of TORQ as a company, but apparently they are very big in the cycling world. I went along to a selection day for the Trail Team and got to try out some of the gels, and they were absolutely delicious! A lot of people in the ultra running community are starting to use these products, and you will probably start to see them cropping up at more races as they further penetrate the market. I pretty much use these gels exclusively now, although will still use whatever I happen to have lying around or whatever is available at the aid stations if necessary.
How Do They Taste:
There are lots of flavours to choose from, including strawberry yoghurt, black cherry yoghurt, orange & banana, raspberry ripple, rhubarb & custard, forest fruits, apple crumble and banoffee. In general, these are all absolutely delicious. As opposed to most other brands that I have used where the flavours simply make them palatable, the TORQ gels are genuinely tasty. My particular favourite are the strawberry yoghurt ones, which really do taste exactly like a yoghurt. Rhubarb & custard and raspberry ripple are also fantastic, although some may potentially find them a little too sweet. I haven't tried the apple crumble ones yet, but have heard good things. The only ones that I don't like are the banoffee flavoured ones, as they have a horrible synthetic flavour (although they don't actually use artificial sweeteners). But otherwise, I thoroughly recommend giving them a go.
What's In 'Em:
Similarly to the GU gels, they are predominately a mix of maltodextrin and fructose - although unlike GU they use a 2:1 ratio of maltodextrin to fructose (different scientists say this is the optimum combination...). Each 45 g gel gives you 114 calories, so you get a little less energy per gram than with the GU gels, but you get a bit more gel per packet. They also contain electrolytes which are essential for long runs, but don't contain the added amino acids that GUs do - although I personally doubt these have any effect when actually running anyway (they're really more for recovery).
How Much Of A Faff Are They:
Not too faffy at all actually. Whilst they are more in the syrupy realm of gels, I find that they're not too sticky, and you don't get much leakage from empty packets in your pocket. I have had issues with other gels in the past which are far too sticky, meaning I can't empty the packet and it just slowly drips out while I'm running (I also found that in hot weather, the contents actually seep out of the sealed packets of some brands of gel). TORQ gels are not like that and I quite happily dump empties into my pack, inevitably forget about them for a few days, but then don't have to worry that the pack might have turned a bit crusty by the time I go to use it again. They are long and thin which makes them quite easy to squeeze everything out. I also find them easier to excavate from my bag than the GU packets which can be useful in a pinch. Also, it's only minor, but the tab at the top is easier to pull off than for the GUs, particularly with cold hands.
How Expensive Are They:
I thought that they were a little more expensive as far as gels went, but actually they are a little cheaper than the slightly smaller GU gels at £1.45 each (less if you buy in bulk). I was happy to pay the extra when I thought they were expensive, but actually now I am even happier to use these as my gel of choice now. You can buy direct from the TORQ website, or from the Ultra Marathon Running Store.
TORQ do a whole range of products for training as part of their TORQ Training System, including carbohydrate bars (awesome flavours, but they do essentially the same thing as the gels which I find easier to eat when running), TORQ Energy drink powder (another source of carbs and electrolytes), and TORQ Recovery drink powder (full of protein and amino acids - I don't normally bother with recovery drinks other than milk, but the mint chocolate flavour is lovely).