I realized too late that the flask cap I mention in this video is no longer available. But you can shop for all of the other products featured in this video at the links in the description. ⤴️

For races definately flasks. Bladder only on solo adventures when there is no water available for hours

Properly cleaning and drying a bladder is more hassle, so for shorter runs I use a flask or two. For longer runs, bike rides, when it's hot, etc. (not races, no water stations...), I take either the bladder or bladder plus one or two flasks. I only ever use water in the bladder, for the reasons you mentioned. I use Source Tactical 3 l bladders for hiking and mountain biking (in a Deuter backpack), and a smaller Source Widepac 1.5 l bladder for running (in a running vest). I shortened the original hose, added some neoprene insulation tube to it (easily found on eBay from many sellers), and installed the Source Quick Connector (SQC) kit on the drinking end of the water tube. I use a Source Tactical Storm no-bite valve which plugs directly into the hose connector. Source Tactical also makes an accessory called Universal Tap Adapter (UTA): unplug the drinking valve from the hose, plug in the UTA, and reverse-fill the bladder from a tap, a plastic water bottle, or a drinking flask. This way there's no need to remove the bladder from the backpack/vest. I'll also mention, even though this probably doesn't apply to most running scenarios, that the Platypus Quickdraw water filter comes with a hose that ends with a CPC connector, which is fully compatible with SQC - so the filter can be plugged in instead of the drinking valve to reverse-fill the bladder. Water bladders are indeed more cumbersome to clean, although a few accessories help with this. I only use bladders with a wide opening that I can put my (large) hand into for cleaning. For the hose, I use a Deuter Streamer Tube Brush (by the way, the Deuter Streamer bladders are made by and are identical to Source Outdoor bladders). I use a no-name hydration pack drier (a plastic thing that can fold or spread a bit) to help keep the bladder open for air drying. There are various tricks to minimize the need to clean. If you are too tired after a trip, just throw the (empty) bladder into the freezer, and clean it later. You can also wash/rinse the bladder and the hose, empty it out and, rather than waiting for it to fully dry, keep it in the freezer. Take it out before going out on the next trip. For a deep clean, if the water starts tasting bad, use a citric acid solution (or vinegar, but the water will likely have some vinegar taste later) or a bit of hydrogen peroxide to soak the bladder and the hose. I usually disassemble the drinking valve, clean the individual parts with a brush, then dry them thoroughly. It is indeed inconvenient not being able to tell how much water you have left in the bladder. I am always wondering if in the future someone will develop a flow meter that can be spliced into the hose. Although it would be yet another part that needs cleaning...

I thought you were going to insult bladders in general, and I was about to throw hands! Your points are 100% valid for long distance races, especially filling/refilling. For hiking I think they are still great

Great video, Jeff. For long races (100k and above) I use both bladder and flasks. For the reasons you mention, the bladder is only for water, while the flasks can have ionic. The main reason I carry both is that I can easily skip quite a few aid stations (and saving a lot of time) instead of stopping to fill up flasks. Also, I don't think it's too difficult to fill up a bladder while it's in the pack. Yes, you can't completely fill it up, but I can usually get 1 liter in there and it's fast to do. That's worth doing and carrying, it it means I'll skip the next aid station.

I've arrived at a slight different setup after a lot of experimenting. The idea came from watching an elite ultra runner cruise by me and at a fast downhill clip. She had no problem reaching behind her to pull out a hard water bottle and then put it back. I believe she had one of those older Solomon packs. In any case, this got my wheels turning. The trick was to find the best size water bottle with the best flip-top cap. I found the Smart water bottles evangelized by thru-hikers were too tall and skinny. A few months later, I was doing some grocery shopping and noticed that next to the Smart bottles they had these 700mL Essentia bottles that were shorter, and their cap design was perfect. I picked up a couple and ordered an Alpha 4.0 vest. After several trials on longer unsupported runs, I figured out that carrying 2 Essentia 700mL hard bottles could be done, but that it was more comfortable to have just one. You only need one for those quickdraw situations on the downhill. To round out my system, I carry a soft flask with a filter up front (so I can quickly react of a great water source all the sudden appears on the trail), and an extra (usually empty) soft flask in the rear. Most of the time, my 700ml hard plastic alone gets me to the next aide station or creek crossing. If there's a particularly long water carry and/or a hot day, I'll fill up the 3rd flask (1L) as an insurance policy, bringing my total capacity to about 2.3. This system allows me to keep a lot more of my calories up front and go longer distances without having to take off my pack for those additional calories. No sloshing. Very little bounce. I think for shorter, faster efforts with aid stations, I might stick with the same system but a smaller vest that has the rear pockets. UltraSpire's Momentum looks good, but maybe one of the other brands has those rear bottle pockets that I should consider?

Great video. I would usually rely on flasks, but for longer races I would use an additional bladder as a backup only. However I like your idea of just extra flasks in the back of the pack instead. Thanks for the video

Really well explained Jeff. I had so many questions around this

Love the idea of carrying extra flasks. Good tip.

Good tips, keep them in mind for my first marathon race next month in Rotterdam 👌🏼🏃🏽‍♀️👊🏽

Great video. Simple and on point sections.

I use a source bladder with a addon piece you put on place of the mouth bite, so that you can refill the bladder with a regular water bottle. Quite a handy system, the bladder never leaves my trail bag during a race

Great video, Jeff. I was considering getting a bladder to supplement the two flasks in my vest but I've seen the light, so to speak, and you've swayed me to opt for two spare flasks stowed away to be swapped out when needed. Really useful and insightful video.

I like your thoughts and many of them are spot on. I will say though that there are some places here where my bladder comes in really handy. When I'm out up by My Tamalpais and there's no water for miles, the bladder is the way to go. And in a race I did a couple years ago one of my bottles broke. It was a really warm day and I was going through water really quickly. I would have be great to have a bladder. If I could find a bottle that I was sure wouldn't leak, I wouldn't mind carrying it in the back, but I have terrible luck with leaky bottles! I miss the hard-sided UD bottles they used to make. Great video as always!

Great ideas Jeff. I appreciate you sharing your thoughts. I have been torn between purchasing a bladder or additional flasks. You have made a compelling case for the flasks. Thanks!!

Thanks Jeff. Great tips. Carrying extra flasks is the way!

Very good video with excellent points to consider. I've been debating how I want to proceed with my hydration set-up. I'm finally able to be comfortable with a pack - the Salomon Adv Skin 12. However, as with all hydration vests, if I use the flasks up front, the vest bears down on the back of my neck. It is very uncomfortable. This is because I'm a woman who is not skinny and I have these fatty things up front. Because of the need to snug the vest against my body, this causes the flasks to contour with my body and it causes the back of the vest to pull on my neck. When I ran and rode a horse (same time, alternating), wearing the bladder was much more comfortable than having flasks. I landed a small 8 ounce Gatorade from a fellow trail user on the same run/ride as the bladder use. It fit nicely in the front pocket and didn't interfere with my running movement. For purposes of electrolytes, I'd much rather have a bottle I can rinse and later recycle. Though if I get skinny and lose the fatty things in the front, and flasks cease to be a problem, I would possibly switch to carrying electrolytes in the soft flask because those vertical pockets for the flasks are otherwise not handy for anything else that I can think of except perhaps my thin summer sleeves. So in the end, it can depend on body geometry. And I rarely like to entrust well-intended people with property that means the world to me. They can hold the button on the water cooler though! That's a great help while I finagle the hydration pack. Bummer the flask caps are no longer offered. I'd really want to use those if carrying extra flasks.

I started this video thinking you were wrong, but you’re not - all valid points. I’m sold.

I now like the idea of using a flask. Thank you -great idea!

Agree with everything you said-they’re such a faff to refill and I hate cleaning them though using baby bottle sterilising tablets then storing the pack in the freezer works well. Gets rid of the lingering taste issues too 😊👍 ATB Karen

I run medium distances, up to 46 kilometers . I usually use flasks. But I believe that in a workout close to 3-4 hours or in a race up to 45 km is better to use the bladder . I like your idea for 2 full flasks and 2 empty . Maybe I'll try it at a race in October. Nice video Jeff. Thanks

Thank you for sharing your thoughts! I have utilised my bladder in combination with my soft bottles in a specifik way the last months on long unsupported runs - carry water in soft bottles in front and in the bladder I carry VERY strong carbohydrate drink (mixing 500g of carbohydrate mix into 1l of water). That way I can carry a huge amount of carbs, easy to digest, easy to get to, at the same time that I can drink plain water according to my thirst.

Great video and good to hear your views as always! I'd add that the tipping upside down of a full pack and sucking out the air bubble is a total pain on a race too but not as annoying as that slosh,slosh,slosh if you don't. When I take extra full soft flasks though I've found those blanking caps create that exact noise, so I just use the normal drinking caps and pack them carefully. A bladder IS useful if you want to add weight to the pack on training runs though, 1L is 1Kg obviously and the train hard fight easy mantra makes this a go to for me on long runs, quite a mental boost when you realise a) you don't mind the weight any longer and b) your race day pack is going to be 2.5kg lighter than the one you're used to! I love my soft flasks too though! :)

Good stuff - totally agree with all the points. I once realized at the bottom of Grand Canyon my bladder couldn't hold water. Lovely... Only thing I'd add is for hot and fast pace races, I drop the vest during daytime and use handhelds. Really helps cooling down, and minimize your load. Worth trying for races like Javelina or Black Canyon.

Great practice. Couldn't agree more. I use to carry 2 flasks with CHO or Electrolytes and a 1/4 full Bladder just to have some clean water with me. If a need to i will fill the bladder too, or wash my face, or give it someone else since i don't drink from that hose. The greatest truth is i never have a clue how much water i carry in a bladder. (also you posted the video on my birthday :-) )

I like the idea. Gonna design it like that for myself. Thank you for sharing your experience :-)

I found this very helpful. I am just starting to do longer runs and have been looking at hydration packs.

This video is great, I recently got my first running vest Solomon Active Skin 8 which I love. I do have a similar conundrum in that I like Nuun in one and water in the other however, I am often running with my dog and like to bring water for her as I have a collapsible bowl too. I think I will take your advice of additional flasks filled and in the back. I am not crazy about bladders but felt I should be ordering one - not anymore. I am curious if you have found these leakproof caps anywhere else as I would like that peace of mind, two back ups filled and not worrying about getting my dry stuff wet. Cheers!

Thanks for sharing I use both depending on my needs.

Good idea, Jeff. I decided to buy two extra flasks instead of a bladder because of your valid reasons. Flasks are quicker to swap and fill. As a leak redundancy, it is good to have multiple smaller backups than stored in one large source.

I think it's a really good idea...Didn't know why i'd never thought about it...Thx

Excellent video 🤘 I’m a front pocket guy and if I want to carry more than I do the two extra flasks in the back. Most important is water intake. I also carry the smaller flasks that I carry gels in 😎

You make several valid points but one feature I like with my bladder is the insulated sleeve. I'm doing a 50k this weekend and plan on starting with a bladder with half ice, half water so I can have cold water while I run. Once the bladder is empty I'll switch to flasks for easier refills. At my pace, the few grams of extra weight to carry both won't make a difference. In most cases, however, I'd prefer flasks for a race, or better yet, a handheld if I don't need the gear storage of a vest.

very good explanations! i was wondering which is better but did not want to learn only from my experience. thankk you for sharing! very clear, simple, practicle explanations!

You have enlightened me. Thanks a lot.

Ok, I will switch to flasks. Good points all around.

really good points, thx

Great video. Thanks for the tips with volunteers ;)

I’m investigating buying a running vest but haven’t quite made a final decision. Super thankful for your timely video because you’ve convinced me the bottles are the way to go. I have a bladder pack for long hike but it’s to awkward for running.

I used to use exactly the same old Salomon backpack pocket to put the 2 extra flasks. Now I put them in the compressport belt during winter longs then when the all the water points are still frozen.

I agree with you . i carry 4 flasks .. had terrible experience with a bladder in an ultra and stopped using them ever since

Great analysis. I made the same conclusion (except that i do not use filters ... not making long enough races :-) ). Extra point : Noise. It's always difficult to get rid of all the air in the bladder to avoid noise at each step. For the flask, simply suck the air ... I just discover your channel and it's full of good ideas. Tank you for sharing them. Have nice races and trips ...

In my experience when my shoulder pockets are stuff with bars and other stuff and the flasks are half empty it's also a pain of getting the flask back into the front pocket. Just as difficult as trying to get a full bladder into a full backpack. Adding to the annoyance is that I have to try to wiggle the flask back into it's pocket at every zip I take. For zipping from the bladder all that is required is putting the tube into my mouth. No fiddling required.

I’ve never done an ultra race longer than 50K and they typically have aid stations every 6 miles or so. For races, I only run with a handheld and a gu and cliff bars in my pockets…I don’t carry a pack…it’s just added weight and the add stations are close enough with food and water…I can see if you do a longer race in adverse/changing conditions with larger gaps between add stations you may need to carry more clothes and other stuff and would want a pack…I have done several adventure runs…R2R2R, Zion Traverse, and other 20+ mile runs with not a lot of water available, and always carry a bladder and maybe the front flasks…I find I get much more consistent hydration by having the hose right next to my mouth and all I have to do is sip on it. So easy to do while running…taking the flasks out of the vest while running and then returning is a major pain. So much so, I find I drink less often. Bladder is so much easier to drink out of. If I only need 1 liter of water on a long run that wasn’t a race, I’d opt for the bladder every time. I’ve never had one fail, but agree cleaning is not as easy as a flask. Yes you have to take the pack off your back to refill, but I’ve never had an issue with just opening the pack and refilling…I don’t remove the bladder from the pack…it’s not a race, so it’s really about being able to carry the most water and making it easy to drink.

Camelbak bladder (3L) has been reliable n super easy to fill. Perfect for some folks that need more hydration and use water only.

thanks for share, very useful !

I'll go against the grain, i prefer bladder,lol. Never had an issues with leaks and find fill/refill with the sliding closure quick and simple.

You had me at "Jeff Pelletier." Always rock solid advice. I prefer the Salomon wide mouth, bullet bottom soft flask. Hard to find. Expensive. The best.

Another point is that flasks on the front side make it easier to distribute payload weight better. With a bladder especially a big one a backpack may have a tendency to shift its position.

Thanks Jeff, I use a bladder primarily because of the volume but after watching your video will switch to flasks. Setting up and cleaning the bladder for some reason gives me a mental block on getting out on the trail.

Interesting, good points...

Hi Jeff, i love your videos. I did the Tot Dret race last year and realised the o-ring connector on my bladder became faulty when i was at the gear check-in at Gressoney. It started to leak so badly i could not use it. I'll stick with flasks from now on !

It takes some experience to know your consumption out of a bladder and if you know how much you need to drink for a certain distance at that day, it's a good way to go for a bladder. I use my bladder a lot when I don't have to refill and use it mostly on solotraining on the trails and occasionly on selfsupplying trailevents aswel. I always carry a spare flask with me, JIC.

I've always had bladder problems ... especially if I've had too much to drink

This video has helped me a lot! The big issue I have with the bladder is the bounce/slopping of water moving up and down (not air pockets). It drove me nuts having the bounce bounce bounce on my back for mile after mile.

I agree bladders are a hassle. But I like having the extra water. My vest is a lightweight one with only a cargo net, but I'm gonna try to rig a way to carry two extra bottles like you said.

Have only experienced longer solo runs and having to carry 3liters on me, no real fill up places in between. The one thing I do dislike about a bladder is not being able to gauge how much water there is left. That's I'd say the biggest reason. But that's why I'm sure to first finish up the bladder and then go for the bottles. I can see that for a race that just having bottles to fill up is much more efficient in many ways though.

When you are in the mountains and you are missing water and its that time of year when there is still some snow left or just some new snow has fallen, you can stuff snow into the bladder and it will melt on your back from the heat as you continue your trail.

I’ve always used bladders in the past. Last 65k race though, I really felt I lost a lot of time at aid stations fiddling with it and that annoyed me a lot. So I bought a Salomon 12 L and am switching to front bottles. Now, if only races could open up in my part of the world... thx for the video!

I'm glad that I'm not the only one who struggles with bladders! 😂

I use both bladder and flask depending on the situation. One tip is that if you use a bladder you can add a in-line water filter like the Sawyer squeeze which is really convenient and gives you the same advantage as having the built in filter in the XA.

Good logic, and I like your idea of packing extra flasks. Last year I was on a self-supported 50k w no water source. Filled both flasks and also had a 2L bladder. The bladder ended up leaking and was bone dry by mi 10, so with 21 still to go, I had to ration what was left up front. Ahh, good times!

Thanks Mr.

Jeff, Thank you for sharing your thoughts, based upon your considerable experience. Two questions. What make are the sealing caps you showed in this video, which you use on your flasks? Also, have you any experience or knowledge of the Salomon on/off caps?

i run with a 1/4 full metal bottle (Idk, I just like it as a quirk). It's good to bang on for animals, or chuck at a coyote if need be. I thought I was clever bringing it all the way full on a longer summer trail run, and dropped the dang thing straight on a toe and broke it 4 miles up. Water is heavy. Do not carry all of it in the same container. Am now team vest/flasks.

Thx for this Jeff, as an ultra runner too I see this.

I've done the same, ditched the bladder. I like having 2 flasks with an empty katadyn 3L filter bag in the back if I need to really load up with water.

thanks your sharing

Definitely knowing how much fluid you have is a real advantage to flasks. I have had a few "What - can't be running out already?" moments with my bladder. Time to look at carrying flasks. I might have to continue carrying a bladder to serve as water source for my partner though! :-)

Good idea 👍

I have two reasons for using a bladder: 1) I personally can easily get through 1L of fluid an hour on a hot day. I'm training for an ultra with more than 2 hours between aid and no along-route drops allowed, but the majority of vests don't seem to be equipped with more than about 1L of flask storage, and that was if I didn't also encounter the issue of 2) the fact that as I woman I find it's an absolute nightmare trying to use chest mounted flasks if you have any chest whatsoever. The vest deforms too much over your chest and the flask just doesn't fit in the pocket. If you try to put the vest on with flasks already loaded it feels like you're going to burst them! (If anyone can recommend a vest or belt with more than 1L of non-chest flask storage (or has any other ideas for these problems) I would love to hear them!)

Thank you sir.

@Jeff Pelletier, one question you didn't happen to cover: which do you think has the advantage for drinking whilst running? I use both flasks & a bladder because I find drinking from flasks fine when climbing/fast hiking in races (where I'm moving slower). But if I want to drink on downhill or undulating terrain, the hose/bladder situation is less fiddly than pulling out a flask from the front pocket. Granted, I don't like the extra long straws as I don't like them in my face/peripheral vision, which some would say prevents the need to pull the flask from the pocket.

That Salomon XA filter flask is really a game changer at least for me. In my beginnings I used to run a lot with a bladder but not anymore. With the flask I am able to refill my water almost everywhere.

Only used a bladder pack once, it leaked and damaged my phone so loved your video and great tips 👍

FWIW, a bladder can be useful if you have to administer an emergency enema (it happened!). I use a bladder/flask combo on long solo runs, however after running dry on a recent outing have got myself an XA flask. Sorted.

I've experienced all those downsides of bladders, plus I find them difficult to fill up to the nominal capacity.

Dear Jeff. Where did you get the flask cap showed at 7;58 on the video? Thanks a lot keep doing these great videos

I have 2 Solomon flasks and just would like to buy a bladder for extra water during the solo long trail run. Thanks for the great video which saves my money and trouble. I will buy 2 extra flasks.

Couldn't agree more! As of now, I only use my bladder for hiking. Carrying several flasks is a great idea, thanks a lot :) Btw: does a bigger isolation jacket fit into the Salomon ADV Skin 12? I am asking because my running vest (5 liters) is too small for me, so I am looking for a bigger one that can store my change of clothes and some warmer layers...

You had me at "monitoring fluid intake."

I’ve bought an additional flask (4 in total) which I’ll use for my next race & supplemented with 3/4 full 1.5 Salomon bladder with water. The first aid station is at 40km & that’s after 3k metres vert gain, likely under a hot Aussie sun. I’ve only ever put water in the bladder & used the flasks for electrolytes & carbs Agree though the flasks are simply way more practical & convenient to use, especially filling water from rivers and streams.

I have ran out of water mid way through a 12 hour hike because of bladder, because I didn't ration my water properly. I haven't used it since. For running I only use flasks and if I need more water capacity I use dirt cheap solution. I just take a plastic bottle full of water.

You should check out these bladders, solves a lot of the problems you talked about Source Tactical Gear 3L Widepac Low Profile Hydration Reservoir

Got to say, those were actually good points... Managing to fill the bladder is not that complicated in my opinion, and I still find it useful to be used alongside flasks. On hot conditions I already dried out flasks quickly, and having the bladder was life saving.

Not being able to monitor my fluid intake while using a bladder has left me incredibly dehydrated at marathons, and so I almost exclusively only use flasks now. Same even for my long hikes in the backcountry, I tend to carry nalgenes now instead of a bladder, and keep them in a rotation for filtration and use. And I agree, many bladders are a huge pain to fill during races. I still remember when I was volunteering for an ultra trail run a few years ago how much of a struggle it was to get the racer’s bladders filled quickly and efficiently for them, and how difficult some of their bladders were to close up properly without making a mess.

I only use a bladder in very hot summer days for long runs, with few opportunities to refill, but never in races for the reasons you state.

Good point about volunteers. I had one at an aid station once, I handed him my handheld and it filled it up with water and got everything else completely soaked, ruined my snacks and my already opened cube wrapper. Now I am like, "NO" - give me the water and I will fill it up myself, 20-seconds and I am gone.

I haven't had a good experience running with bladders. They feel heavy and the water sloshes around and creates a lot of bouncing. I've found that bladders are great for hiking or walking when you're not sweating profusely and don't want to take off your backpack to drink water.

The slider on the Salomon bladder is over designed which makes it unnecessarily difficult to open and close. I have one but I also have a 2 liter Nathan that is much easier to open and close. I agree that bladders are not the best for competitive runs that have aide stations. I use my bladder mostly for long training runs where there are no aid stations. Very thoughtful VLOG! Thanks!

Good points there. Though the "missing volume point" (e.g. you're only using 11L out of a 12L liter pack if not using front flasks) isn't quite accurate, one can always put more stuff in there instead of the flasks.

Hi Jeff thanks for the great content. Where did you find the caps you mentioned at the 8:00 minute mark? I haven’t been able to find them online and love the idea of using those to store extra flasks. Thanks!

For anyone who doesn't know, a great way to eliminate the mold problem is to run water through the cap after use and completely pull them apart afterwards to dry. This includes the silicone nipple being detached from the plastic lid. In the event of mold in the silicone, I've found a q-tip to work quite well at getting the mold out and a bottle brush for the inside of the flasks.

First time using a bladder.. Heading to a water fountain.. Do I need to fill the bladder... Is there enough to get me to the next water source.. Having to stop and pull it out to get a look... Went right back to water bottles. You always know how much water is in your bottle at any given time.

Good Idea to have one or two smaller flasks in the back 👍.

First option is indeed 2 flasks in front. Only for longer runs with little access to water I also use a bladder. I empty my flasks first so I can refill them whenever possible. I also always carry a filter with me

Really great thoughts! I've got the Salomon ADV Skin 12 and have thought about how best to carry more than the 2 soft flasks of water. The bladder is something I've thought about, but I also wonder if simply sliding 2 additional soft flasks (filled) into the bladder compartment or into the back side pockets would work. I've got a 55 mile run coming up, and so I might try this out. Thanks for the video!!!

Way way back I tried running with a bladder once or twice.. hated it. Too much slushing (even with all the air bled). Nope. Started carrying one (or more) ordinary (plastic) bottle(s) of water (with a diy drinking tube attached) and strangely even an half full bottle didn't bother me a bit... weird. Only later on proper front pocket vests became available and softflasks...

Redundancy is a super important concept - depending of course on how isolated you are on that trail.

I don't drink water unless I run over 50k.