Selouyanov on Endurance (Pt. 1): A Guest Post by Dr. Smet

Russian training methods and Russian sports science. Raise your hand if you (a) love these things but (b) don’t read Russian. Then you probably owe almost everything you know to Pavel Tsatsouline, THE great interpreter of that subject and almost the most influential voice in American exercise. Pavel created an appetite for English-language popularizations of Russian training research much greater than any one man can satisfy, even a pedagogical genius like Pavel. Today guest author “Dr. Smet,” a Russian-educated physician practicing abroad, takes us behind the curtain of Pavel’s latest book for a direct look at some of its source material. Dr. Smet’s blog Girevoy Sport After 40 is required reading for lean solid dogs, lazy badasses, and grapplers and kettlebell competitors. He has graciously allowed me to cross-post his original piece. -Dog in Chief

Pavel Tsatsouline has finally published his long-awaited book on endurance training, the Quick and the Dead. Despite the hype, in the end I was underwhelmed. Don’t get me wrong: the book has useful information but, as it makes clear on the last page, it is a long infomercial for the StrongFirst Strong Endurance seminar.

Victor Nikolaevich Selouyanov (1946-2017)

The material in the book is based on the research of a few Russian sport scientists and coaches, most notably Victor Selouyanov, previously mentioned in my blog [Girevoy Sport After 40 -ed.] in the post “The Heart is not a Machine.” Selouyanov was a bit of a renegade, and because of disagreements with the science establishment he never completed his doctorate. Nevertheless, his contribution to the understanding of training endurance was invaluable, and Russian sports science is still bitterly divided between his followers and opponents.

Selouyanov wrote several books, among them two that are of interest to me: Physical Preparation of Grapplers and The Development of Local Muscular Endurance in Cyclical Sports. Both deal with endurance, and Selouyanov’s concepts allow a systematic approach to training endurance in pretty much any sport. I will briefly and loosely summarize the most relevant parts of the book for grapplers (my current love).

Muscle fibers

From practical point of view Selouyanov was talking about two distinct groups of muscle fibers: glycolytic and oxidative. Glycolitic muscles are capable of producing great force, but because they are not very good users of oxygen they get tired quickly – in a few seconds – and are not very useful for activity that requires endurance. Oxidative fibers, on the other hand, do not produce as much force, but are virtually impossible to fatigue in aerobic conditions. Their power production drops from maximal to about 80% and stays there for a long time.

What gets oxidative muscle fibers at the end is the accumulation of lactic acid and, more precisely, hydrogen ions and the resulting acidosis. It happens if the production of lactate exceeds its elimination, which happens when you demand too much work from your muscles.

Oxidative muscles are good users of oxygen because of large number of mitochondria in them. Mitochondria are “power stations” of the cell where oxidation – the reaction between various substrates and oxygen – occurs, which results in the regeneration of ATP, the fuel that feeds the muscle fiber and allows it to contract.

Therefore, in order to develop endurance you have to do two things: build myofibrills (units of which muscle fibers are composed) and build mitochondria around them.

Classification of training loads based on long term adaptation

Methods of training are aimed at changing the structure of muscle fibers in the skeletal and myocardial muscle, as well as other systems (endocrine, for example). Every method is determined by several parameters that reflect the external features of a given activity: intensity of contraction, intensity of exercise, duration (repetition, series of the actual duration of exercise), rest interval and the number of sets or series (explained later). Each method activates internal processes which reflect immediate biochemical and physiological effects of a given training method. The final result is long term adaptation, which is the actual goal of using a particular training method.

For the sake of brevity I won’t spend much time on the internal processes elicited by each training method. I assume everyone reading this is a practitioner and is more interested in the description of the method and the long term adaptation it causes.

And so the methods are classified as follows.

1. EXERCISES OF MAXIMAL POWER

External features:

  • Intensity of contraction – 90 – 100%
  • Intensity of exercise – 10 – 100%. 

Barbell squats and bench press, for example, are activities with low intensity of exercise, but high intensity of muscle contraction. Throws performed with the wrestling dummy in high tempo and low rest intervals is the example of high intensity of both muscular contraction and exercise. 

  • Duration – usually short
    • Strength exercises are usually done for 1 – 4 repetitions
    • Speed-strength activity – up to 10 reps
    • Speed exercises – 4 – 10 seconds
  • Rest intervals – depends:
    • For strength exercises – 3 – 5 minutes
    • Speed-strength exercises – 2 – 3 minutes
    • Speed exercises – 45 – 60 seconds
  • Number of series/sets depends on the goals. 
    • So called “developing” sessions use 10 – 40 sets
  • Weekly frequency depends on the goals. 
    • If the goal is to develop myofibrills in the muscle fiber the series is performed to failure
    • If the goal is to develop mitochondria the series are performed to light fatigue

You just witnessed a fairly common phenomenon seen in Russian literature: the discordance of content and the title. This is exactly how it is in the text: weekly frequency – to failure or not, depending etc. It doesn’t make sense, I know, but we will have to forgive the good professor. – Smet.

Long term adaptation. 

  • If performed to failure, this method leads to the increase of myofibrills in glycolytic and intermediate muscle fibers
  • If done to mild fatigue – leads to the increased phosphorylation in glycolytic and intermediate fibers, eventually leading to the increase in mitochondria

2. EXERCISES OF NEAR MAXIMAL POWER


External features:

  • intensity of muscular contraction – 70 – 90%
  • intensity of exercise – 10 – 90%
  • Example – barbell squat or bench press done for more than 12 repetitions
  • If you increase the tempo of exercise and reduce the periods of contraction and relaxation of muscles, you turn these exercises into speed-strength type. Examples include jumping and throwing wrestling dummies

Duration:

  • generally 20 – 50 seconds
  • strength exercise are performed for more than 12 reps
  • speed strength exercises – 10 – 20 reps
  • speed exercises – 10 – 50 seconds

Rest intervals:

  • for strength exercises – more than 5 minutes
  • speed-strength activities – 2 – 3 minutes
  • speed activities – 2 – 9 minutes

Weekly frequency:

  • This method is aimed at increasing the power of anaerobic glycolysis
  • Currently there are no publications that demonstrate positive effect of near maximal exercises performed to failure.
  • However, numerous studies show deleterious effects from this type of exercise.

Long term adaptation:

  • most effective for increasing myofibrilles in glycolytic muscle fibers
  • no increase in mitochondria
  • If terminated well before failure or performed with pauses, this method leads to the development of mitochondria in glycolitic and intermediate fibers: there is no excessive acidosis in the muscle cell, and lactic acid is eliminated during rest. 

There is a method used by Russian athletes, called 10×10. An example in the video below:

Grigor Chilingaryan, one of the specialists from the laboratory of sports adaptology that was founded by Prof. Selouyanov. Start at 3:00

The session consists of three exercises: pushups, jumps and pullups, all done for 10 reps in a circuit, for ten rounds, the intensity –  about 80%. As you can see, the athlete never comes close to failure, and each rep is follower by a short rest – which gives the muscles a chance to get rid of lactic acid and avoid acidosis. This is the example of near maximal training without destroying the body. The coach recommends starting with lower rounds and building up gradually. 

To be continued

Your weight is junk data, your mirror is unreliable, and your feelings are fake news

Feeling fat, looking fat, and being fat are three separate things. You can “feel fat” without looking or being fat. I’ll hazard a guess that it’s mostly emotional, but even when you’re not being particularly neurotic, you can feel fatter or leaner depending on the fit of your clothes and your posture.

You can also look leaner or chubbier from day to day, just based on factors other than bodyfat. Posture is a big one. So is lighting. And biggest of all are the ebbs and flows of hydration and muscle glycogen. Do you ever glimpse yourself in the bathroom mirror and look surprisingly lean? Well unless little elves came during the night and gave you liposuction, you just happened to eat a combination of things that inadvertently flushed out subcutaneous water without depleting muscle glycogen. On that particular day, your skin happens to be at its thinnest and your muscles right at their fullest. Result: you look a little ripped, at least for a couple of hours. 

If you track your bodyfat every day, you find that there’s less correlation than you thought among your weight, your bodyfat level, and your appearance. Right now I weigh a lot, a level that was only normal when I was a powerlifter eating like an ox. And I don’t look very lean either: I’m waterlogged, with thick skin and blurry abs. And subjectively I feel a little chubby: I’m wearing the big-waisted jeans that I keep in storage for the occasional squatting cycle, when I bloat into a stout, gluteal Michelin Man, and if I strip off my shirt at yoga these days I look like a tanned marshmallow with a rubber band around its middle. And yet to my amazement, when I run the numbers, I find I’ve got way more lean body mass with just the same amount of fat as last summer, when I had a nice, wasp waist. Strange as it seems, even though I feel bloated and look pretty “blah” in my shaving mirror, I’ve got maybe the best body composition of my life right now.

So why the difference? It’s that I’m holding way more water too. Yes, I’ll have to change some things if I’m suddenly offered a photo shoot as a middle-aged underwear model. But for now, since no one has recognized my potential—give me a chance, Madison Avenue! I could be great!—I shouldn’t change a thing. 

I’m glad I know that, because now I won’t mess with success. But I want to underscore that the only reason I know it, despite cockeyed subjective impressions, is that I’ve got an objective measure in the Tanita scale. 

So here’s today’s takeaway for everyday lean, solid dogs:

  1. Your regular bathroom scale only gives you junk data, your mirror is unreliable, and how lean or fat you feel is fake news. 
  2. If you’re going to track something, make it something objective and reliable. Spend $40 for a Tanita scale. Track your actual bodyfat percentage. Everything else is evanescent, subjective, or both.
  3. Try out the many successful, easy approaches for leaning out, and (here’s my $.02 for the menfolk), once you get to 12%, just hold steady there. I’m not alone in thinking that that’s a sweet spot: easy to reach, easy to maintain, and makes you fit and healthy and mobile and trim without being onerous.

Forty-Mile Ruck: Lessons Learned

To prep for the (in)famous Star Course, I tried a 42-mile ruck march.

I’d read one man’s AAR suggesting that in training you aim for 40 miles (64km) in something close to 10 hours, and on paper that sounded almost reasonable. It’s only 15 minutes per mile, right? Heck, I’ve motored along at that speed in perfect contentment for plenty of 12-mile marches with a 30# pack. So with just 20# dry (not even 10kg), wouldn’t I cover at least the first half of my journey at that pace? And if I allowed myself a full 12 hours, plus an extra hour for lunch, that would be almost leisurely! Right?

That was HUBRIS, and I got punished! Instead of treading a merry 13 hours, I slogged out a tough 15½ hours, and rather than a carefree and gay picnic walk, at times it felt like a death march.

This was a major lesson in all the factors that can slow a march down. Let me count the ways!

What I Did Badly

Feeling so sluggish, I sensed I was in for a long day. But I had no idea just how long.

First was my own poor condition. I’d been training hard, demanding a lot of my foot muscles (which work overtime in yoga and kettlebell lifting too), and the day before my ruck romp, I’d had a small migraine that I tried to cure by testing my rep max in the kettlebell snatch. (That worked pretty well, by the way.) Coupled with a 4am wakeup, it’s little surprise that I felt like hell when I started my walk, and it slowed me down. By mid-morning I was already an hour behind schedule. And that was before other adverse conditions started piling up.

I am blessed to live out in the country. Only problem is, my body thinks it belongs in a different country.

What other adverse conditions? Next was the heat, which is my personal kryptonite. I’m stocky and descended entirely from Northern European bog dwellers. Even in modest heat, a full sun clobbers me like an axe.

I made some poor nutrition choices too. Normally in these long events, I thrive on a scant 25g of carbs per hour and, being keto-adapted, I draw the rest of my calories from body fat. It’s a trick I got from ultra champ Zach Bitter and it makes me immune to the usual nausea and GI trouble of endurance events. But on this morning I treated myself to a big, sugary frozen mocha, and it was way too much carbs and gook. I’ll spare you, gentle reader, an account of the results and just summarize them as “sub-optimal.” Lesson: Just 25g of carbs per hour.

If you want to geek out on this stuff, read the work of Mike Prevost.

By my choice of routes, I also gave myself a (poorly timed) lesson in how much you can be slowed by terrain. The Army has researched rucking speed and found that, even more than pack weight, you’re slowed by factors as mundane as the ground’s surface. And elevation gain is another biggie. When climbing a 10% grade, you cut your speed in half. (EDIT: Researcher Adam Scott finds that it’s only a one-third reduction.)So on one steep 4-mile stretch, I climbed for almost two hours.

Nor did I factor in stream crossings. Foot care guru John Vonhof insists that you remove shoes and socks at streams, carry them across, and dry your feet before putting them on again. I did this each time, dutifully but grudgingly, but I ate up nearly an hour and disliked feeling my way painfully across the stream bottom in sore, bare feet. Lesson: Bring water shoes and a microfiber hand towel. On trips where I’ll recross the stream at the same point, I can even stash them near the crossing to wait for my return trip.

Finally, maybe it wasn’t the best idea to wear brand-new boots. Though they didn’t need much breaking in, they still required time-consuming experimentation on the trail, trying different combinations of socks, liner socks, and lacing.

Ridiculous math like this is an example of why the metric Mondopoint system is so great. You measure your feet in millimeters. That’s your size. Simple.

However, there was one thing about these boots that was a godsend: they’re actually big enough! My toes have never been so free. I owe this too to John Vonhof, whose simple trick is to remove the insoles from your shoes, set them on the ground, and stand on them. If your feet lap over the insoles at any point, or even touch the edge, the shoes are too small. That’s how I went from a size 9.5 to a 10.5 Wide!

What Went Great

Aerobic base: Aerobically this trip posed little challenge. As in all my training, I throttled back enough to stay within my “MAF” heart rate (“max aerobic function”). And even on such a long ruck, I found, as long as I stay within my MAF heart rate, I can put my legs on cruise control and motor along indefinitely. My feet might get sore, but my heart and lungs can hack it just fine.

Our Lady of Electrolytes and Mr. Delirium

Electrolytes: At long last, I didn’t cramp! I can’t take credit for this. The unsurpassable Lean Solid Girl met me at my turnaround point with a princely feast of burritos, trail mix, cold drinks, and (best of all) electrolytes.

Blisters: I only got one blister, on my heel. Zero blisters would be better, but I’ll take this as a victory considering this was a distance PR in boots that were new out of the box.

The Great Takeaway

The home stretch. From this bridge, it’s 3 miles to my door. The last time I passed it feeling this tired was only a few months ago. That night I was doing my first 12-miler, but now that’s just a warmup. Reflecting on that was a real morale boost. #cookiejar

I didn’t quit. That’s the great takeaway. At 5:30am, only 5 minutes into the day, I still had a lingering headache from the day before, felt like hell, and had no spring in my step, and I thought, “I picked an awful day to do this. It will be amazing if I actually finish 40 miles today.” And I was right on both counts: it was terrible timing–WTH kind of plan is “be sick all day, then max out on snatches, and then do 40 miles the next day?!”–and it’s amazing to me that I finished it. I should have rescheduled–stupid stuff is stupid, and it would have required effort to choose a worse day for this. But once I (foolishly) committed to it and decided to stick with the (dumb) plan, it was almost a certainty that I’d finish–eventually–as long as I didn’t quit.

Rucking up at Mile 23. Don’t believe the smile, it’s a lie. I’m feeling pretty sorry for myself here. Out of the frame, milady’s Prius is whispering, “Give up! I’ll take you home right now. How about some air conditioning?”

And that, friends, is the big lesson. (Cue the “rousing emotional crescendo music!”) It seems that in an event like this–a low-intensity slog played out over a very long time–there’s almost no way to suck so much that you can’t finish. There’s no opponent to KO you, pin you, or steal the ball, and you need zero coordination or athletic talent–it’s just walking. Physically the demands aren’t even very intense or the perils great: you won’t get a concussion or cascade off the side of Mount Everest. You can suck as much as you want for as long as you want, but unless you decide to quit (or you get abducted off the road by a UFO), you are pretty much assured of succeeding eventually. As Goggins says, “No talent required.”

Gear Check

Final installment in my after-action report from the GORUCK D-Day Heavy Challenge.

The faithful, indomitable, light, nimble “Moose Head” rucksack. I love this thing. Made in the 1930s, it was intended by the Swedes as a cheap mass-production item for hurriedly equipping a big army that Germany would choose not to tangle with. Eighty years later, with just a little sewing, it’s my favorite pack.

What Worked Out Great

1. Webbing: I had about 6′ of webbing and it saved me twice. First we had to carry an insidiously-shaped rock a few miles uphill. I bound it up like a birthday gift and then some genius added D-rings and carabiners so that folks could hang it from their pack straps. The final effect was like a newborn boulder in a Babybjörn. It still sucked, but it substantially reduced the Suck Value. Second, I broke a pack strap at dawn, but it took all of 30 seconds to improvise a fix with the webbing. Without it, I would probably have washed out of the event over that petty equipment failure. So write this down, someone: webbing is the duct tape of rucking.

Weight: 40g. Not quitting the whole event over a busted pack strap or wasting everyone’s biceps cradling a f#&%ing rock: priceless.

2. Spare shoelace: Whipped this out to secure the flag to the pole better. Again, it nullified what could have been a huge pain in the butt for essentially zero added weight.

3. Rocky S2V boots: Thank you, Sgt. Šileika! The Rockies were champs. My search for the perfect all-round boot is over!

I’m blown away by the contrast to the Moab Ventilators that I wore last year. The point of the Ventilators is that, with their mesh sides, they let water and sweat flow out and let air rush in. It’s a great idea for running trails, but not for sloshing around in surf and sand because your shoes and socks fill with sediment. I got grit between my shoes and socks, between my socks and sock liners, and between the liners and my skin.

Perhaps not coincidentally, the other teammate who wore Rockies completed a “Heavy-Tough-Light” (i.e. he is a freak who did three events back-to-back over 48 hours, totaling well over 70 miles). And the teammate who wore Ventilators got a silver dollar-sized blood blister so heinous and unearthly that I expected an alien to spawn from his heel. (Amazingly, he just cheerfully popped it, dressed it, and walked on it for the next 12 hours without grimacing. People are freaks, and this guy must have the pain tolerance of a barn animal.)

4. Synthetic fabrics: Impressed by Lean Solid Girl’s successes, I left behind most of my old-school cotton, wool, and hair shirts and wore so much stretchy space-age fabric that I felt like Spider Man. And it worked great: I stayed warm, dry, windproof, and free of chafing.

It was only at midday that I wore a cotton shirt (one of the dozen awesome $4 Bundeswehr quarter-zips that I stash everywhere–#notaffiliatedIjustlovethem). But as soon as we got wet, I changed back to polypro gratefully.

5. Tights: Goofy yoga shorts are still great, but in water and wind, I was even happier with running tights. Even better, mine had built-in knee pads.

6. Categorized bags: Since my old-fashioned ruck only has one big compartment, I sorted gear into four marked bags: Food, Shirt, Jacket, and Head & Foot Stuff (hat, headlamp, sunglasses, socks, and foot care supplies). It worked great. Next time, I’ll color code the bags too.

7. More sock changes than a Madonna concert: I brought two extra pairs of socks and sock liners, and I rotated through all of them. Again, cheap insurance. I’ve had great success with the combination of Finnish M05 “liner socks” (which are socks unto themselves here in temperate climes) and FoxRiver liners, so I won’t mess with success.

8. Tailwind and GU: Here too, I owe Lean Solid Girl, who’s a past (and future?) runner, for initiating me into the secrets of distance athletes.

9. My hydration bladder: Our team had at least two burst hydration bladders, which did not enhance their owners’ lives. Usually I’m the first person to cheap out and get suckered by a false economy, but I’ve never encountered this problem even after hundreds of miles, so I’ll keep using Hommitt.

Dumb Ideas

1. Powerlifting knee sleeve: It’s stupid to change your game plan at the last minute, and that includes switching to gear you haven’t tested. I grabbed a squatting knee sleeve on the way out the door because I worried about padding my sore knee. It guarded my knee from abrasion, alright, but over 40 miles it knotted up some soft tissue behind my knee from the pressure.

2. Leaving my electrolytes to chance: I prepared for pushups poorly enough. I didn’t need cramped arms on top of that, but I chose to trust that I’d get all my electrolytes from the Tailwind. Dumb. Electrolytes are cheap insurance, just like webbing or an extra shoelace. Without Mike the Forester’s generosity, I’d have been in trouble. Next time I’m bringing extra electrolytes.

3. Poorly secured pill bottle: To help with pain, I cleverly brought some CBD, ibuprofen, and caffeine pills, but I foolishly hung the bottle from a carabiner with my gloves, and within an hour it was lost.

D-Day

Today’s the day, friends. 24 hours, 40+ miles, with logs, sandbags, PT beatdowns, and surf torture along the way.

Wherever you are today, get after it! Hammer along with me and (I’m completely serious about this), please remember my team and me in your thoughts and prayers. I may be Buddhist, but I’m not choosy about where I get my numinous intercession.

The Tao of the Lazy Badass

“Like water, volume is soft and yielding. But volume will wear away rock, and it beats the crap out of excess fatigue. As a rule, volume wins over fatigue. This is another paradox: what is soft and voluminous is strong.”

from the lost training manual of Laozi (Lao-Tzu)
A difficult book, but the most important one I know.

In the most original book on training in decades, Pavel Tsatsouline describes a certifiable badass, a special operations ninja-type whom he pseudonymously calls “Victor.” Victor combines a pair of already-extraordinary feats into an extra-extraordinary combination: he runs ultra-marathons of up to 100 miles AND he does pullups with an extra 160# hanging from his waist. That’s a freakish level of endurance and world-class strength, a combination so rare as to seem impossible. (As we have said before, strength and endurance are rivals.) That is what makes Victor an elite among the elite, a certifiable badass.

To reach those heights, Victor trains in a very special way: lazily. Or to be more precise, with low fatigue. From his amazing accomplishments, you might suppose that he spends all day exercising and puking his guts out. Nope. Most days he works out for all of 30 minutes, much of it with a 24kg kettlebell, which is strictly a “Joe Average” weight, and some pushups and pull-ups and yoga. He left behind even low-key barbell training long ago, explaining that when he deadlifted, “I felt my ego pushing me harder and faster than my body wanted to go. So I decided to limit myself to one kettlebell and two [steel exercise] clubs …”

As the core of his lethargic-looking super-routine, Victor runs … sloooooowly. Slowly enough to breath only through his nose, with rhythm and relaxation. He writes:

“The key is … the LOW INTENSITY. I use a heart rate monitor, and I stay at 60% to 65% of my [max heart rate]. This means that I am often walking on the hills. If I ran [faster], my recovery time would be much longer.”

Allyson Felix knows the Tao of the lazy badass. Her coach, Barry Ross, keeps his athletes fresh and unfatigued in training. See Easy Strength.

Pavel and Victor are insistent: Victor is not succeeding in spite of his low-key training but precisely because he throttles back. Victor has perfected one way of applying the near-magical formula for productive and happy training: do as much work as possible while staying as fresh as possible.

Are those twelve words too much to remember? Then stencil this on your kettlebells, barbells, and running shoes: Volume Without Fatigue. That is the red thread that runs through many of the successful training philosophies out there, connecting disparate-looking approaches whose only apparent link is that they work well, and it is the subject of our next series, “Farewell to Fatigue: The Way of the Lazy Badass.”

Your author. Not a badass, but I make up for it in laziness.

Stretching for kettlebell lifters who hate to stretch

https://www.yogajournal.com/poses/side-stretch-satisfaction
Anti-rotation. Al Kavadlo doesn’t twist and fall here because his QL is keeping his waist rigid.

The poor quadratus lumborum (QL). It does much more than its share during one-arm movements like kettlebell swings and presses, where it keeps your torso rigid and facing forward. It needs to be stretched, but if you are a blocky, stiff muscle head, good luck getting into the standard “straddle stretch.” Before you know it, you blow off stretching it completely.

That’s what Jump Stretch bands are for. If you’ve knocked around the powerlifting world for more than 5 minutes, you probably think of JS bands as “accommodating resistance” for your weights.

In American powerlifting circles, most of us know Jump Stretch bands as tools for “speed day,” when they let you safely accelerate light barbells fast, so you don’t launch them.

But from their inception, JS bands have been at least as much for stretching and mobility as for resistance, and they are a godsend for stretching tissue that’s ornery or hard to get into position for. Pecs, shoulders, lats, biceps, triceps, hip flexors, and quads are all much easier and less arduous for me to stretch with bands than on a yoga mat.

But the quadratus lumborum is the poster child: normally I can scarcely get into position for QL stretches without being limited by flexibility (e.g. hamstrings in the straddle stretch) or muscular endurance (e.g. holding onto a door frame).

But if you have a band and somewhere to anchor it, you can stretch out your QL without annoyance. For comfort, use a deadlift strap for your grip so that you can hang for as long as you want without your hand tiring.

Like yoga in a dungeon. You get to wear the same skimpy shorts, but you’re tied up and hear clanging metal.