Sunday 13 January 2013

UltrAspire Impulse Waist Pack Review

The Christmas holidays were fantastic fun, with plenty of food, wonderful company, and general good cheer all round. To ensure that we remain jolly for as long as possible, a few friends and we celebrate our very own holiday ("Fakemas") on January 2nd. It's basically all of the best parts of Christmas all over again, with a big emphasis on awesome presents. This year for Fakemas, I was very happy to receive the UltrAspire Impulse waist pack which was on my letter to Santa this holiday season.

There are three main ways to carry fluid and equipment around with you during an ultramarathon. The first is to use a handheld bottle, which has the benefit of being very minimalist but does not allow you to carry too much additional equipment. The second is to use a pack, which has the benefit of giving you scope for carrying additional gear but does mean you have the additional weight and the inconvenience of carrying something on your back. The third option is to use a waist pack, which sits somewhere in the middle as it allows you to carry more equipment but leaves your back unencumbered, preventing overheating and reducing potential chafe points. 

Until now I have never found a waist pack that I liked the look of, since typically they seem quite bulky compared to the very well designed ergonomics of the Salomon S-Lab hydration vest that I normally use. The Impulse on the other hand is very minimal (at only 232 g), consisting essentially of two bottle pouches and a belt with a couple of pockets.

The waist belt is quite minimal, with two bottle pouches connected by a small belt, with a few additional pockets
Despite the minimal nature of the pack, it is incredibly well designed with a huge number of nooks and crannies for storing all of the equipment that you are likely to need on a typical long run. Firstly, the two bottle pouches are separate entities connected by a lightweight metal clip, allowing independent movement while you run. This means that the whole pack does not move up and down as you run due to the rolling of your hips, and you can have the pack pulled quite tight to prevent any unwanted movement. The bottle pouches keep their shape, so there is no worry of the pouch collapsing when you take the bottle out, so putting the bottles back while running is easy to do without breaking stride. There is also a small hole in the bottom to allow any overflow to run off.

Rather than a clip to hold things together at the front, the pack is held in place by a very robust but lightweight metal buckle that connects slightly off to the side behind the slightly more padded pocket on the left. This keeps an even pressure across the belly and waist and means that the pack can be kept tight if required without worrying that the connection will ping open under the strain (something that has happened to me in the past with plastic clips).

The connection on the belly is very minimal with a small but robust clip that sits off to the side behind the wider padded pocket
The fit can be easily adjusted, and a quite neat little feature is that the excess belt can be tucked behind the main pocket on the right hip so that there is nothing flapping about as you run. Whilst flapping straps are not exactly a huge problem, over a long period of time they can really start to grate. To be fair, I will trim the excess off anyway, but it is a very streamlined design.

The excess of the waist strap can be tucked away behind the pocket on the right hip
The pack comes supplied with two UltrAspire 0.6 L Human water bottles. These bottles have a finger loop for easy access when reaching behind you (saves on yoga classes), have an ergonomic 'angled' design to allow drinking easier, and have a simple top which allows access to fluids by either twisting or pulling the mouth-piece. The bottles are very good, and I typically use a similar bottle in the UltrAspire Isomeric Pocket handheld which I absolutely love. The problem here however is that they are a little too big. Over shorter distances (less than 20 miles) it's not really noticeable, but over longer distances I could really feel the tops of the bottles digging into my kidneys. I returned from a 35 mile run last week feeling slightly sore, and this is definitely not something that I would want to have to contend with for a full 100 miler. It is a real shame as the finger-loops really do work brilliantly at accessing fluid on the run, but I have found that using a smaller bottle (such as my trusty and cheap High5 0.5 L stubby bottles) prevents the problem. But despite the loss of the functionality of the finger loops, the design of the bottle pouches still makes access to the bottles very easy on the move as they are stored at an angle away from the body, preventing the need for complex contortions.

The pack comes with two UltrAspire 0.6 L Human water bottles, but I found them a bit too tall
Despite the minimal appearance of the pack, there is plenty of storage space for anything that you might need on a long run. Firstly, there is a large zipped pocket on the right hip which is easily large enough to hold an iPhone, with plenty of space for additional supplies (some gels, a pack of tissues, car keys, etc.). The zip has an easy to grasp toggle which makes accessing things very simple while running, even with frozen hands (as I found this morning).

The main pocket is very large, and easily holds a large mobile phone with plenty of room for additional bits and pieces
On the left hip, there is a smaller pocket that is large enough to fit 2-3 gels and is easily accessible while running. If you are racing and there are plenty of checkpoints then this would probably be fine, and for training runs it is more than enough. But if you are doing something long and unsupported you would probably need to use some of the other pockets to store additional gels. It is also unlikely that you would be able to fit in much in the way of real food (sandwiches, flapjacks, etc.) if that is your preference.

Other gel brands are available...
On each of the bottle pouches, there is a mesh pocket on the outside that can hold various bits. You could easily fit a few more gels in here, but I found it a useful place to store my emergency supplies such as a pack of blister plasters, some anti-chaffing cream and some Elete electrolyte solution. These pouches are a little more difficult to access on the move so I would say that using them for lesser used emergency bits is probably preferable.

Plenty of space for additional nic-nacks in the bottle pouch side pockets

And finally, there is a very basic but functional (and of course lightweight) shock-cord on the rear of the pack for storing a waterproof jacket. This easily holds the jacket in place as you run, and there was no issue with the jacket falling out. This was something that I was a little worried about, as I have had "slippage" issues when storing my jacket in the loop at the base of the Salomon 5L pack (usually when the pack is empty and there is nothing to compress it in place). But pulling the cord tight seemed to keep things more than secure and I can't see this being a problem. I also found a useful way of storing my headtorch when the sun comes up (without having to use up valuable pocket space) by looping the strap around the waterproof.

A waterproof jacket can easily be stored using the simple and lightweight shock cord draw-string system at the rear of the pack. You can even store a head torch if you're feeling extra cunning
Overall, I really like this pack. I made sure to completely fill it when I tested it to make sure that I got a feel for the comfort of it under race-type conditions. Even with both bottles full, a waterproof, and all of the various pockets filled up, I didn't really notice too much that it was there. Maybe I'm just used to carrying a lot of junk in my trunk? Who knows. The maximum I have run with it fully laden so far is 35 miles, but it was perfectly comfortable and I didn't really think about it at all. It is difficult to know if running a 100 miler with this pack would show any problems that I do not notice on shorter runs, but the potential for niggles certainly seems minimal based on my experiences so far. Of course, this is the pack favoured by Karl Meltzer for 100 milers, and hell - he seems to do okay with it! 

I did find the issue with the bottles pushing into my kidneys to be a bit of a problem on longer runs however, but using slightly smaller bottles alleviated this issue. Since the smaller bottles are my normal go-to bottles, I probably would have switched these in anyway (to cut down on the weight), so I'm not too disappointed, but it's something to bear in mind if you are looking at this for yourself. I would be interested to know if anybody else has suffered from this issue, or if anybody has any suggestions to avoid it, so please do get in touch.

This is a fantastic pack, and its minimalist appearance belies its functional utility. There are some very clever design choices that have resulted in a very comfortable alternative to a small back pack. This pack would be ideal on longer training runs that don't require too much in the way of self-sufficiency (you won't be able to pack your sandwiches in there, but if you can run 50 miles on a few gels and a liter of water you will be laughing), or for a longer race that is well supported but requires you to take a little bit of kit with you. 

The big question for me is; would I use this in place of my trusty 5 L Salomon pack? They are very similar in what they allow you to carry (minimum kit for most 100 milers not in the mountains, some gels, some emergency supplies, and a couple of bottles), and they are both well designed in the way that they fit as you run. The benefit that this pack has is that it only sits on your waist, so will prevent  the overheating associated with carrying a pack (even a lightweight one). The honest answer is; maybe. But without trying it out on a very long run I can't be sure how it will do over the distance. I can't see any additional problems arising over time that I haven't already foreseen, but who knows? I might give it a whirl at the North Downs Way as a bit of a test and see how I go. 

All photos courtesy of Long Suffering Wife Enterprises PLC...


  1. I've fallen out of love with waist packs. I if not carrying water they are fine, but put any weight on them and I just can't stand the strap digging in on my stomach. Sure, you don't notice over a few miles (or even more if not in the fells), but overtime I just feel like I'm fighting them as a breathe or eat.

    Unless one breathes only with their chest (in which case belly breathing should provide greater efficiency and comfort over the medium to longer distance) I think a vest pack (there are plenty out there now) provides far less constriction and thus far greater comfort and performance.

    It is absolutely a horses for courses thing and I love the idea of having an uncovered back from a sweat point of view, but I think the killer questions is; "If carrying any weight would you rather it pulling on your shoulders or on your stomach?"

  2. I do agree with you on the point about carrying large weights on your stomach, and that is exactly the reason that I have never bothered with one before. But this pack struck me as being very non-bulky whilst still giving plenty of space for essentials. I certainly wouldn't use a waist pack if I needed to take lots of kit with me (which I know you can do with some waist packs. In those cases I would definitely prefer a pack for exactly the reasons that you mention. But if all I need is a little additional kit for a race (a bottle, some gels, a waterproof, a phone, and a couple of small emergency supplies) then this could be a good alternative to a pack.

    Of course, I love my Salomon vest pack and it's done me proud, but if this can do equally well whilst leaving my back unencumbered (particularly for races on hot days) and also whilst minimising contact with the body to reduce rubbing points, then that would be great!

    I didn't notice any problems with breathing over the course of 5+ hours of continuous running last week (albeit over non-technical - if slippery and muddy - terrain), and I am very much a conscious belly breather now (after suffering from some issues last year which I managed to trace back to my breathing). I had it done up pretty tight as well, but I guess I kept it low on my waist. But without actually trying it for a 100 miler I guess I won't know.

    It's definitely horses for courses though, and I'm just interested in trying out things that may improve my comfort while I run. Having the option of a handheld, a waist pack, a race vest, a light pack, and a heavy pack means that I am pretty much ready for anything! I would raise a corollary to your question and ask; "If the weight that you're carrying is relatively small, would you rather cover only a small portion of your body, or spread it over a much larger area?"

  3. Hey Sam,

    Thank you for your review of this product. It was very informative. May I ask you this one question. How would this waist pack go with the average 600mL/20oz bottle that you get from a supermarket or convenience store? The rounded bottle.
    Look forward to your reply.
    Kind Regards

  4. hi sam. just realising it is you i had pizza with in chamonix on eve of UTMB/CCC. this is a great review of the pack. i am going to get it as i struggling with upper back/shoulders stiffness with salomon s lab 12 litre b pack.
    hope you are running strong! Declan Faulkner

  5. Hi Jonathon, I haven't tried using a typical bottle but I would guess that a small bottle of water would be a little narrow and might move around a lot. The wider bottles would probably fit quite nicely. Most sized refillable water bottles will fit though. If I can, I'll grab one and try it out for you.

  6. Hi Declan. Yes I remember! It rained a lot... You were off taking photos with the Salomon team for most of the day weren't you? How did you get on in the race? It's a great pack, I'm going to give it a go at Transvulcania I think and see how it copes in a race situation! Hope that you're running is going well - any races coming up in the near future?

  7. It sure rained hard Sam. Was delighted with ccc run and time. Got in 16hrs 33 mins. 380th I think. Really enjoyed the 4 days I was in chamonix. No luck for utmb this year but have a place in Lakeland 100 as fall back. Hoping to build up to it with Wicklow way ultra in march and lost worlds 100k at giants causeway in may. Would love to do a run abroad in heat for a nice change. Lol. When is transvulcania? Just ordered the pack above too. Declan

  8. Hi,
    I don't have the "kidneys" problem even I use two 26oz human bottles rather than the original 20oz. I do feel the cap of bottles a bit but if you turn the bottles 90 degree(finger loop pointing outside), it will help.
    Also, I found that I wear it a bit lower then you.

    1. Hi francisshots. Thanks for the comment. I have tried the bottles in all different orientations since I got it, but it still feels more uncomfortable to me than when using the smaller bottles. I also wear it a lot lower than the pictures here might suggest (right down on my bum). I'm quite short so maybe that's the difference? I still love this pack though, and wore it for Transvulcania earlier this year and it worked great!

  9. Sam, I would like to ask what the impulse feels like if you were to use just one full bottle. It looks ideal for me, two bottles in summer and in winter I could use one of the bottle holders for extra winter gear. Just checking what you think, Thanks Mark.

    1. Hi Mark,
      I have actually done this and it works fine. I often shove my jacket and other bits into one bottle holder, and a bottle in the other one. It works fine for me. This was the setup I used for Transvulcania and also what I started out with on the SDW100 (both times with an additional handheld).
      Hope that helps!

    2. Thank you for your quick reply Sam. I'm just starting to build-up distance and trying to find gear actually up to the job is a nightmare. There is far too many running products which are just rubbish. The Impulse looks ideal, am only a 30" waist and 31" round hips, I bet you are about the same so might have bottles rub kidney area, some I,ve tried stick out too much and affect arm swing. The angle of bottles looks just right on this. Thanks Again, Mark

  10. great review, very helpful Sam, thanks. I'm just off to order one from Ultramarathonrunningstore.


Note: only a member of this blog may post a comment.