BLISTER PREVENTION: A Foolproof Guide to Blister Management

[damon_james]

Below is an article I wrote and (pilfering info from far and wide) recently revised re: Blister Management. I am posting it here just in case anyone finds it useful, or as a starting point for further discussion. Happy trails, Damon.

BLISTERS ARE A MISSION CRITICAL FACTOR ON ANY TREK.
The importance of blister management cannot be understated: For experienced bushwalkers, blister management priority is up there with adequate hydration and competent navigation.

Blisters result from frictional forces (caused by repetitive rubbing) that cause separation of the skin cells at the layer responsible for the mechanical strength of skin. In the space that is created by the separation of the layers, fluid collects.

If you are not prepared, blisters can ruin your walking experience and end your walk. If you are serious about blister prevention, here’s how to avoid them:

1. BOOT QUALITY Buy the most comfortable boots you can find. Good boots can be expensive, so be prepared to fork out. Any experienced hiker will tell you that boots are not the right area of your recreational budget to economise. Also buy a good quality closed cell neoprene inner sole for cushioning/dampening of shear forces in the skin.

2. BOOT WEAR Ensure that your boots are properly worn in. Do not wear new boots on a long walk. Wetting your boots and doing hill repeats with a full pack is a good way to break-in new boots or walking shoes. Note that despite your best intentions, boots will not correctly break-in if you simply walk around on flat ground without a load. You will know your boots are ready when you can walk for a full day over uneven terrain without getting "hot spots" (pre-blister sensitivity) on your feet.

3. LACING The Dark Arts of Boot Lacing hold many opinions and theories. The best one for blister prevention is to lace your boots as tight as possible without causing foot pain. Blisters form easily if the boot causes too much friction (lacing too loose) or if the skin is too constricted (lacing too tight).

4. WEAR SOCK LINERS This is basically a double sock system, consisting of a thin polyester sock worn closest to the skin (causing low friction) and a thicker mid-weight woollen or polypropylene sock worn closest to the boot (causing high friction against the insole). Studies with Army recruits show that this is one of the most effective strategies for blister-prone feet. Recruits who had fewer blisters also had fewer other injuries.

5. SOCK QUALITY As with walking boots, don't skimp on quality: Expect to pay up to $40 for a good pair of socks. A good sock retains its shape when wet, moulds to your foot and does not wrinkle or bunch. Brands such as Icebreaker make high quality hiking socks and sock liners. Mid-weight wool blend hiking socks are generally best, even in hot weather, due to their moisture wicking ability and level thermal properties. In snow, a heavy-weight sock is more suitable. Toe socks are also good but can be difficult to put on when damp. Modern dual-layer "blister free" socks are also a good option.

6. SOCK SIZE If you are faced with a choice between a slightly smaller sock or slightly bigger one, buy the smaller size as this will reduce in-shoe movement and wrinkling.

7. WEAR GAITERS Sand (and even dried mud) in the boot or sock is a very quick way to increase abrasion and encourage blisters. You’ll be constantly tipping sand & debris out of your boots unless you wear gaiters or long pants. Knee high or ankle gaiters are both fine.

8. ANTI-CHAFE BALM Many walkers and track runners will not head outdoors without applying a high quality anti-chafe balm to their heels, toes & balls of feet. Balms work by decreasing friction and subsequent heat load. Brands such as Body Glide are highly regarded but may only be available in specialist running stores or online.

9. BLISTER STRAPPING It is perfectly possible to walk with strapped blisters, however walking with UN-strapped blisters is completely ruinous and can reduce the most hardened walker to tears. Blister strapping is an absolute must for your first aid kit. Running out of blister strapping has brought many walks to a premature and inglorious end. Carry at least 2x rolls of Fixomull stretch or Compeed patches (these have a very high coefficient of friction), available from any pharmacy. Strapping/taping blisters also helps prevent the blister from de-roofing and infecting. If the blister is full, you can relieve the fluid by pricking the top corners prior to taping.

10. HOT SPOTS Taping susceptible areas prior to a walk helps prevent blisters. Identifying “hot spots” early on, and addressing the area (e.g. applying tape, changing socks, drying feet etc) may prevent blisters altogether.

11. CONDITION FEET Trim toe nails and file off calluses - leaving thick calluses will only give you deeper blisters and possibly blood blisters. Train in the shoe for the activity you are doing. Conditioning will help your skin build up resistance to the shear forces that cause blisters. This won’t guarantee you a blister-free experience but many hikers find it makes all the difference.

Happy Trails Damon

[Hallu]

I am very blister-prone and over the years I've found what I needed. First of all, the inner sock liner doesn't work for me. It's way too unstable, the inner sock slides too much against the outer sock. So yeah it prevents blisters but it also prevents you from walking with sure footing. Rywan and other brands nowadays make socks that are 2 socks in one, stitched in key places (base of the toes and on the footheel). So it prevents blisters without making you lose stability. They're 20 $ a pair, no need to cough up 40$^to me.
The second most important thing is shoes. I only go with Salomon now, because Keen, Zamberlan or Patagonia shoes all failed me. For some people it's another brand, but the idea is, you need to find the right one. And loose lacing is always better than tight lacing. Your feet swell when they're hot, so I always lace up a bit losely first... For me, taping, or using creams never worked. Sweat and friction will remove the taping easily, and the creams bring back the instability problem, you will slide inside your socks.
The third most important thing is simply to walk. You need to develop thick calluses on your toes and heels. That being said, if you're comfortable in your shoes (usually meaning if you have regular feet with no weird shape), you won't even need to have calluses as friction will be minimal. To me though it's a lot better to have a blister forming under a callus than on regular skin. They're less painful, take longer to form, and with enough callus don't appear at all.
On treating blisters, the best to me is to pierce them on the side in the evening. They will dry up and the top skin will harden during the night. Again, compeed patches are very expensive and useless : your sweat and sock friction will remove them in less than an hour on a warm day. Compeed don't seem to get that blister prone walkers are the ones who sweat a lone (increasing friction), and that means the patches will fall off.

[vicrev]

While walking a couple of years ago ,came across a girl sitting on the side of the track,boots off & in tears,her feet were just about all blisters,terrible state.....It turned out the place she bought the hiking shoes advised her to go 1 1/2 sizes up from her normal shoe size....Ruined a walk she had planned for years......Whatever advice you take,try it well before you do any serious walking........

[Chezza]

On the subject of liners, I use the Injinji toe sock liners. I find they are a nice snug fit due their stertch fabric and don't slide against my skin at all.

They function as an "all-over" second skin, and insulate my feet from frictional hot spots. They wick brilliantly and usually dry overnight when they are wet.

[slparker]

No offence to the OP, but I reckon that these guidelines are dodgy. Or, rather, some may work for some people in some conditions but as blanket rules they can be worse than useless.

Rule 1 & 2 should be footwear, not boots, as shoes and sandals are completely acceptable footwear in many areas.
Rule 3 is completely wrong. if in boots, the laces should be firm around the ankle joint to prevent heel lift otherwise the tightness of the laces should be up to the walker's comfort - 'as tight as possible' will be excruciating, especially as the foot swells with normal walking. Has the author actually tried forcing the foot to walk in boots where the lacing is 'as tight as possible', I wonder?

Rule 4: Like Hallu I completely disagree with rule 4. What is the point of a system that, especially when it gets wet, increases the bulk, weight, drying time and wrinkliness of the system? OK might work for some (and I know people who swear by them), but I switched to close fitting merino socks some years ago and ditched the 'liners' as worse than pointless. so, not a 'guideline' but it's worth trying for those who consistently get blisters.

5. yep agree - but what defines 'quality'? Some people walk miles in holeproof explorers at 7 bucks a pair but i wouldn't be seen dead without my darn toughs.

6. agree

7. a good idea but is not foolproof in very deep mud - so you still need a sock/shoe-boot system that can cope with mud inundation.

8.don't know, never tried it but seems to run counter to rule 4 and 6 which is about a tight layer of material around the skin to prevent friction against the second sock or the boot. It certainly isn't necessary and if waterproof may lead to maceration of the skin which I've seen lead to unbelievable blisters.

9/10. Completely agree. I've worn strapping tape and/or fixomull in newish boots or on multiday walks and it lasts days even in wet conditions (think south coast track). This system prevents blisters in known hotspots and reduces further friction once they have occurred - much better than any fancy sock, boot or inner layer could possibly work. don't believe me? watch soldiers before a 40 or 80 km route march -they're all strapping their achilles and heels. Circumferential strapping should be avoided, as should any wrinkles in the tape.

11. condition feet. seems reasonable, except why cut off calluses? It depends where they have formed. Calluses on toes may increase shear forces if the forces are tangential to the skin (i.e. a callus on the side of the toe). A callus on the heel or forefoot is probably worse than stupid to cut off as it is actually the conditioning that the author is talking about.

Anyway, my 10c worth which may be different to yours, but my point is that 'guidelines' should be replaced with 'things to try that may work or render you lame if they don't'.

[GPSGuided]

Aren't blisters associated with these 3 factors?

1) Fit.
2) Gear.
3) Distance.

Often individual and situation specific.

[walkabout]

I've never had blisters (touchwood) and I've done a fair bit of walking in the past. I've found what works for me is to tie my boots as tight as is comfortable and to always wear a thinner lining sock and not too thick main sock.

[kitty]

Thanks Damon,

Some good key points there on blister prevention.
It is apparent from the replies that individual outcomes vary, and people need to find what works for them.
For example Compeed patches dont stick to Hallu but they stick to me - just different.

Has anyone tried this stuff - ENGO?
I have no association with ENGO, Ive never tried it, and was wondering if anyone has. They are patches you put on your boots/shoes, rather than patches on your skin.
Im curious if they would work for hot-spots on my boots, rather than strapping my feet to prevent friction.
http://www.blisterprevention.com.au/eng ... n-patches/

Many of the points you mentioned, as well as some others with pros/cons, are on the same website here:
http://www.blisterprevention.com.au/how ... t-blisters

Cheers, kitty

[JohnStrider]

I use the Elastoplast Blister pads to heal my blisters. If I don't have them on me, I usually pierce the blister from the side, let it drain and then cover it with a bandaid, allowing me to continue to walk pain free. After a few days, I find the excess skin has hardened..

[Hallu]

On the subject of liners, I use the Injinji toe sock liners. I find they are a nice snug fit due their stertch fabric and don't slide against my skin at all.

They function as an "all-over" second skin, and insulate my feet from frictional hot spots. They wick brilliantly and usually dry overnight when they are wet.

The injinji socks have been my worst experience ever with blisters. They're too thick, too rough, not slippery enough, and created an amount of friction just about everywhere, especially on my toes, as it's a toe sock design... I did only 4 hrs of walking that day and came home with the biggest blisters I've ever had. A disaster. So it works for some, not for others.

[neilmny]

Not a real blister sufferer but my weird sticking up second toe "knuckles" (both feet) can rub badly on the top of my boots when there is a lot of steep down hills. I use TEKO Merino socks, wrapping the toe knuckles in a cloth type Elastoplast (not plastic they dont work) with the sticky down edges completely does the trick.

[Lizzy]

Thanks Damon,

Some good key points there on blister prevention.
It is apparent from the replies that individual outcomes vary, and people need to find what works for them.
For example Compeed patches dont stick to Hallu but they stick to me - just different.

Has anyone tried this stuff - ENGO?
I have no association with ENGO, Ive never tried it, and was wondering if anyone has. They are patches you put on your boots/shoes, rather than patches on your skin.
Im curious if they would work for hot-spots on my boots, rather than strapping my feet to prevent friction.
http://www.blisterprevention.com.au/eng ... n-patches/

Many of the points you mentioned, as well as some others with pros/cons, are on the same website here:
http://www.blisterprevention.com.au/how ... t-blisters

Hi Kitty,
I tried those patches on a new pair of boots for a walk in Tassie. They got soaked and didn't last long, but long enough to help me wear the boots in a bit more than I already had- so did the job I guess!
Cheers, kitty

[kitty]

Thanks Lizzy, I might give them a try, but I wont expect them to last kitty

[Chezza]

On the subject of liners, I use the Injinji toe sock liners. I find they are a nice snug fit due their stertch fabric and don't slide against my skin at all.

They function as an "all-over" second skin, and insulate my feet from frictional hot spots. They wick brilliantly and usually dry overnight when they are wet.

The injinji socks have been my worst experience ever with blisters. They're too thick, too rough, not slippery enough, and created an amount of friction just about everywhere, especially on my toes, as it's a toe sock design... I did only 4 hrs of walking that day and came home with the biggest blisters I've ever had. A disaster. So it works for some, not for others.

I was referring to these specifically:

http://www.injinji.com/liner-crew.html

I wear them under normal wool hiking socks. They're super thin, very stretchy (which should mean good fit for just about everyone) and very smooth to touch. I wouldn't wear their normal toe socks as mainstay hiking socks, or even some of their thin running socks as liners. I'd fully expect the blisters you experienced in both those cases.

[damon_james]

The 10c jar is on the fridge. Grab a beer

Many thanks SLParker, Chezza, Hallu & others for your replies and great input. As per the title it's a guide not set of rules. Mostly I posted this a starting point for informed discussion about what works and what doesn't for blisters. I appreciate hearing anyone's opinion that runs counter to my current awareness (which is of course a long way from complete), and I'd like to incorporate any new learnings into the next revision (might have to start including some credits ) which may be of more use to more people.

Has the author actually tried forcing the foot to walk in boots where the lacing is 'as tight as possible', I wonder?

Hmmm... actually I'm pretty sure that I suggested lacing the boots "as tight as possible without causing pain". Apologies if this was unclear. For me this actually means "pretty loose", because even moderately tight lacing gives me metatarsalgia (forefoot pain) within a couple of hours. I even lace up pretty loose on the ankles because I generally don't get a lot of heel lift in my current boots, even when knee deep on mud on the SCT in Tas last month.

So far I have not found any sock/shoe system that can cope well with deep mud. Mind you I have not tried neoprene socks, so would also love to hear if anyone has any experience with them.

Cheers, Damon.

[north-north-west]

So far I have not found any sock/shoe system that can cope well with deep mud.

Waders.

To be serious for a moment, last year when I was heading up into the Labyrinth for fagus season, a bloke came down to Pine Valley Hut after dark (log entry said he'd been rained out of his intended three day high camp) in . . . gumboots. They were his only footwear, he wasn't even carrying camp shoes.

[keithy]

So far I have not found any sock/shoe system that can cope well with deep mud. Mind you I have not tried neoprene socks, so would also love to hear if anyone has any experience with them.

I haven't tried full neoprene socks, but I have a pair of older style sealskinz socks that I originally got for mud/river crossings, but I am not a fan. Maybe it's just the fit on my feet but I didn't particularly find them comfortable. I think walking with them in wet shoes could see more blisters occurring.

I have gone to a two sock system. I have these thin Merino socks that I wear underneath my regular wool hiking socks and found it mitigates blister issues for me. If I get a hot spot though, I find using standard Elastoplast adhesive plaster tape over the area prevents the blister. I have a roll of the stuff in my first aid kit.

[Hallu]

On the subject of liners, I use the Injinji toe sock liners. I find they are a nice snug fit due their stertch fabric and don't slide against my skin at all.

They function as an "all-over" second skin, and insulate my feet from frictional hot spots. They wick brilliantly and usually dry overnight when they are wet.

The injinji socks have been my worst experience ever with blisters. They're too thick, too rough, not slippery enough, and created an amount of friction just about everywhere, especially on my toes, as it's a toe sock design... I did only 4 hrs of walking that day and came home with the biggest blisters I've ever had. A disaster. So it works for some, not for others.

I was referring to these specifically:

http://www.injinji.com/liner-crew.html

I wear them under normal wool hiking socks. They're super thin, very stretchy (which should mean good fit for just about everyone) and very smooth to touch. I wouldn't wear their normal toe socks as mainstay hiking socks, or even some of their thin running socks as liners. I'd fully expect the blisters you experienced in both those cases.

Yeah I had the normal crew socks. At the time (about 4 years ago) I don't think they made the liner or at least I didn't find it.

[quill]

Good rundown, there's a fair bit of voodoo involved with footcare in general, this is a decent overview.

I'd add a few pointers for when you get a hotspot or a full-blown blister:

Runners are prone to chafing - on feet, inner thighs and underarms (and nipples, drenched tech fabric can be rough, bleeding nipples are no fun no siree bob). They use a product called Bodyglide, it is what it sounds like, goes on like those Mennen Speed Stick deodorants. Works a charm. Do not use as a preventative as it promotes movement, which causes blisters. But once a blister is coming, there's not much you can do to stop it so the focus turns to reducing the friction you are already experiencing. Of course, still lace up tight, we want minimal movement, but if you have movement anyway, reducing the friction is the best compromise.

Once you have a blister, of course you never pop it. A blister is the epidermis separating from the dermis - the epidermis is about the thickness of a cheap grocery bag. Very very thin and most of it is dead cells migrating up from the stratum basale. It has no blood supply (nor nerve supply I'm fairly sure) and provides waterproofing and a physical barrier against infection. Once blistered, the serum provides cushioning and an aseptic environment for the migration of dermal cells across the dermis again. If the blister is huge and you *must* burst it (or you suspect it will burst anyway), run a length of cotton thread through it with a needle. This allows the serum to drain out slowly via the wicking action of the cotton while preserving the integrity of the skin cap as much as possible.

[Hallu]

That whole "don't pop it it'll get infected" is valid if you're in the jungle with no disinfectant in sight. But on regular hikes, yes you need to pop them in the night so you can walk on them the next day. Walking on a popped blister that hardened during the night is a lot more tolerable than walking on a big bubble of serum that pushes against your dermis. Not to mention that it can get even bigger, will eventually pop during the walk and hurt like hell. After experiencing that pop while walking so many times, I now ALWAYS pop them myself as soon as I see them : I spray some disinfectant on nail scissors, cut a hole on the side of the blister, drain the excess serum with paper towel or a kleenex (very important) and spray some more disinfectant on the whole thing. No bandage, as it needs to dry out and harden for me to be able to walk on it the next day. Oh, and a piece of advice : better shower BEFORE popping the blister or you'll experience quite a burn =)

[slparker]

So far I have not found any sock/shoe system that can cope well with deep mud.

Thin felted socks like the darn tough (there are others, I'm sure) and shoes that won't suck off the feet (salomon works well for me) -I'm not sure why but i htink that firm fitting thin socks works like a 'second skin'. and the shoes, being flexible, means no heel lift at all; so nothing to create friction against the heel - I tried boots as well with no dramas but there was no advantage in carrying 300 ml of muddy water around in each boot, so i went to drainable shoes.

Wash the grit out of the socks at the end of the day, dry your feet and put on clean socks for around the camp. If you still get rubbing or hot spots when you check your feet at your lunchtime stop put on strapping tape over the hot spots (or fixomull). If you get a blister there are several methods that i have seen or used to treat them. Some are not particularly evidence based and some seem to work very well.

My comment about 'the author' was not directed at you - more on the original author that you derived the info from. I think the list has some good points but they are too context deficient (i.e. the callus guide).

[vicrev]

For what it's worth,there is a facebook thingy on how to tie bootlaces , it recommends leaving the first four row of holes laces on the loose side,tie the next lace crossover in a knot,(If your boots are on the tight side,can help to free them up a bit)then lace up & pull comfortably tight,then instead of doing a double crossover before the bow,do it triple,the laces will not undo......works for me a treat. ........Just tried to find it on facebook,it's there somewhere...........

[quill]

That whole "don't pop it it'll get infected" is valid if you're in the jungle with no disinfectant in sight. But on regular hikes, yes you need to pop them in the night so you can walk on them the next day. Walking on a popped blister that hardened during the night is a lot more tolerable than walking on a big bubble of serum that pushes against your dermis. Not to mention that it can get even bigger, will eventually pop during the walk and hurt like hell. After experiencing that pop while walking so many times, I now ALWAYS pop them myself as soon as I see them : I spray some disinfectant on nail scissors, cut a hole on the side of the blister, drain the excess serum with paper towel or a kleenex (very important) and spray some more disinfectant on the whole thing. No bandage, as it needs to dry out and harden for me to be able to walk on it the next day. Oh, and a piece of advice : better shower BEFORE popping the blister or you'll experience quite a burn =)

Ah - this is what I meant by 'voodoo'... in that what works for one will not for another. I am the opposite - if it will pop anyway I run cotton through it but for anything less than basically egg-size I leave it as is. I find it much less painful and I think the physiology behind the notion of leaving it is sound. Practicality may be another matter, especially if your own experience has been different.

Blisters are nasty business all-round, a small mitigating factor for me is peeling off the skin cap to find fresh, supple, whole skin beneath.

[Maaxxx]

Injinji Toe Sock inners can be somewhat fiddly to get on, especially over the smaller toes but, once in place, they feel great and certainly seem to help in blister prevention. My partner, on the other hand, hates wearing double socks but swears by "Foot Fleece". (Fine NZ merino lambs' wool.) Just wrap it round the susceptible areas and it's virtually friction-free. Not sure whether it's available in Oz. She orders it on line from across The Ditch.
Max.

[Hiking Noob]

I hate boots so I just left mine as loose as I possibly could(have only done the OLT not a proper hike) and they were fine, wore probably four different types of sock, bamboo, cotton and a couple of nylon ones. The cotton ones were the worst but still caused no blistering, I did find in a test walk that the boots had to be either super tight or really loose, if they were in between I blistered.

Like everyone says, do as may practice runs as you can with a fully loaded pack wearing all the gear you intend to wear.


Edit, I lie I did blister, I took some Teva sandals and walked around town in them after the walk and got blisters in one afternoon, worst sandals ever made!

[Eremophila]

Injinji Toe Sock inners can be somewhat fiddly to get on, especially over the smaller toes but, once in place, they feel great and certainly seem to help in blister prevention. My partner, on the other hand, hates wearing double socks but swears by "Foot Fleece". (Fine NZ merino lambs' wool.) Just wrap it round the susceptible areas and it's virtually friction-free. Not sure whether it's available in Oz. She orders it on line from across The Ditch.
Max.

Heard of this fleece a while back, intending to try some once the podiatrist has finished "tweaking" insoles for me.
In fact, the owner of the GOR shuttle, when dropping me off, recommended looking for tufts of sheep's wool on the fences and using them in a similar fashion.
Has anyone tried Condy's Crystals? Seems you can use them to soak your feet over an extended period, to toughen the feet. There is resultant discolouration but would have to be better than blistering.
My biggest issue is the underside of my little toes turning into what amounts to a huge bubble. Extends around to the top of the toe and under the nail, which is rather painful.
Men's boots have alleviated this to a fair extent, they have a square toe box instead of the "pretty" tapered look of the same model boot in the women's style. The insoles are proving excellent so far, but I'm still a way off being able to do the distance walks I'd like to do.

[Maaxxx]

Actually, I'm told "Foot Fleece" is a product available from one of the N Z tour companies. "Hiker's Wool" is, I believe, the more widely available version of the same stuff.

[slparker]

[quote="Eremophila"
Has anyone tried Condy's Crystals? Seems you can use them to soak your feet over an extended period, to toughen the feet. There is resultant discolouration but would have to be better than blistering.
[/quote]

Condy's crystals (potassium permanganate) can be used as an antifungal agent in the way that you have described. To my knowledge it does little to toughen the feet. Application of methylated spirits on the feet is reputed to harden the skin against the friction of walking. It is used traditionally (that is, supported by anecdotal evidence) by soldiers - but then soldiers also used to inject betadine directly into blisters to treat them....

I doubt that application of either of these agents would substantially 'toughen' the feet; perhaps they provoke the same hypertrophy (i.e. callus formation) that walking does but the substance would have to reach the underlying dermal layers of the foot to achieve this. On balance of probability I reckon that this is a myth and nothing replaces doing increasingly lengthy walks in the boots/shoes you are intending to use for a long pack walk.

[RonK]

My wife and I have worn thick double socks for years of high altitude trekking with rarely a hot spot. There is always Compeed in the first aid kit to treat other trekkers blisters.
On boot fit and lacing, when tightened properly the front laces should stop your toes from sliding into the toebox and making contact. That is why most hiking boots have two stage lacing systems with a clincher after the first stage - so the toe and ankle can laced independently. If your front laces are tight but your toes still slide into the toebox, your boot may be too big rather than too small.

[quill]

[quote="Eremophila"
Has anyone tried Condy's Crystals? Seems you can use them to soak your feet over an extended period, to toughen the feet. There is resultant discolouration but would have to be better than blistering.

Condy's crystals (potassium permanganate) can be used as an antifungal agent in the way that you have described. To my knowledge it does little to toughen the feet. Application of methylated spirits on the feet is reputed to harden the skin against the friction of walking. It is used traditionally (that is, supported by anecdotal evidence) by soldiers - but then soldiers also used to inject betadine directly into blisters to treat them....

I doubt that application of either of these agents would substantially 'toughen' the feet; perhaps they provoke the same hypertrophy (i.e. callus formation) that walking does but the substance would have to reach the underlying dermal layers of the foot to achieve this. On balance of probability I reckon that this is a myth and nothing replaces doing increasingly lengthy walks in the boots/shoes you are intending to use for a long pack walk.[/quote]

I can't speak from personal experience but I hear metho is popular with runners, gymnasts, rowers and ballet dancers as well as soldiers. This proves nothing of course but it seems popular among people who would know. I can't speak to how it works (if it does) but I do know the epidermis is only a few hundred cells thick. Regular application of metho would have no problems penetrating to and affecting the dermis. It could be the drying effect thins the epidermis and superficial dermis as water is removed, increasing direct pressure on the dermis. It's this direct pressure which stimulates callus formation.

http://www.coolrunning.com.au/forums/?showtopic=19403

http://www.chalkbucket.com/forums/threa ... ses.25690/