The Palest Ink or Defining Reps

The use of differing ways to distinguish intensity and volume can sometimes be an overlooked variable of training.  A new, or new to me version is called RPE or rate of perceived exertion used to describe the intensity of load.  Another option is the use of percentages of your on rep maximum. A easy example to remember is 80% of your one rep maximum would put you at about 8 reps.  Along those same lines is the Rep range system where you define your intensity by reps you will be staying within 1-3 or 3-5.

(You don’t have to read this as it is in depth for some people to the point it may bore you)     The above example help to the lifter define a intensity and energy systems that you are working within. There a multiple ways to look at energy systems.   Energy systems for example are ATP system that fatigues in about 1-5seconds the creatine phosphate system that can fatigue in 10second or so. There is questionable beliefs and methodologies that explain what the optimal for training progression.  Anecdotally, I find that staying within a certain energy system within phases is the best way to approach a progression.  This is called periodization.  I have discussed the idea of schizophrenic type training where no variable is clearly defined and no long term goal is being trained for, basically madness without means.  Sometimes I think people just train to get the endorphin rush rather than define a long term goal.  I get stuck in this rut from time to time. Either be it from stress, or busyness or just life priorities getting in the way.

All the above being said there is a lot that can go into planning.  In many instances the acronym KISS applies. ( Keep It Simple Stupid) In many instances people will overcomplicate what they do, which can lead the individual to feel like they are not making progress.  All of the above systems work though I think the most specific day to day one is rep range for me it is the one I have used the most.  I have seen people use the percentage system specifically coaches who write team programs and have great success with it.

With RPE I think it is valid and useful for people who are not trying to tax the nervous system by tracking how close to failure you are each set.    However the very worst thing a person can do is not keep track of weight sets and reps.  So if you aren’t writing down what you are doing you are making a mistake.  For female client I recommend a fufu journal, they can bedazzle if they have time.  For males I just recommend a legal pad or one of those 3 hole folders because they only require college rule paper. Techie people can use a phone app but there is something satisfying about putting pen to paper.

In synopsis use what you like to define intensity, but be certain to record as the Chinese proverb goes “The palest ink is better than the best memory.”

Heros and Villian or Duality of Coaching

DC and Marvel  do a great job building characters that people can relate to you, see a contrast where the heroes epitomize good, they are idealistic and symbolic of virtue rarely taking life outside of collateral damage caused by the villain.  Marvel often makes it easy to identify with some villains because much of what created their characters was a type of oppression that humanity created in response to being different.  I think the same is true of a good coach.   A good coach will let you see past the veil that is your goal, and when you arrive, you will be burdened by a new goal.   A villain understands that there will be collateral damage.  In Batman vs Superman Lex Luther’s quote:

“Did you know the oldest lie in America, Senator? It’s that Power can be innocent.”

Contrast that with Uncle Ben from Spiderman:

“With great power comes great responsibility.”

A good villain is burdened by being right. A good coach/teacher is careful to demonstrate and teach how he is right or better, still to allow the student to come to his or her own decision on the matter through trial and error for the sake of progress.  The ignorance of the student background and the concept of his scaffold of knowledge or tabula rasa in areas creates a kind of fog of war for the student, and for the coach in some areas can create a falling away, however, it is for growth of the student.  The job of the coach is growth of the student that he or she may come into their own.  Building autonomy and confidence only comes with experience.

In some instances, however, it will be hard to distinguish a good coach from a villain or a bad coach from a hero because of the experience of the individual and the lenses they wear can create a sort of blind spot or parallel world.  The best I can explain it is as bishop on a chess board.  A bishop on black can never see a bishop on white.

Lastly what I can say of great coaches, villain or hero, is that they stand out.  I think it is their vision they will make many enemies on their way and lose allies with the bridges that they burn, because what they are willing to do often times what those that follow are not.  Their passion is as much a blessing as a curse.  Is there a line between passion and obsession?  I think another thing about people that are brilliant is that they are very close to a madness.

Rough Drafts and You 2.0

 

self made

In various instances in my life I have started projects only to leave them unfinished.   In my earlier days I had it decided that this was some type of curse and a great failing of mine.  I have a multitude of things I want to tackle, but limited time or limited resources or a type of writer’s block that stands in the way of completion.   This is still a failing of mine though it does not upset me as once it did.  I picture the sand man coming to life out of sand or the picture above.

The conclusion that I have come to is that it is better to fail at a lot of things, but not to repeat the previous mistakes.  Though, a more cathartic conclusion I have come to is that perfection is unattainable for us mortals.  However over time I can make things better and more complete if I keep building on what I currently have and know and chip away at old imperfections.   I can see this in books when they print a new edition of the same thing or in software when they try to make things better more functional and user-friendly.    This is why I have adopted 1.0 or Beta in many of my programs as I can update them depending on the feedback, and I modify them to suite the individual so they are more user friendly.  After all there is no perfect program there is only optimal variations differentiated by the user for desired results.

 

What can be taught?

There is something great, motivational, something that can burn.  It is a passion, a desire.  It is something lacking and everyone wants it.  It drives people, it directs them, it is a muse, and a light in the fog of life that steers.  It is a flame and few people can light this fire, in some this fire is sparked, but then smothers itself because nothing is there to feed it.  Sometime there are limited resources that help fan this flame.   What I can tell you about this great something is it is there.  You have to find it, you have to fan it, and when you see people with it you want to surround yourself with them because what they have will feed yours.  For a general understanding of what this something is you can call it intrinsic value.  It is what you find important, why you find it important how it consumes you.   The hard part is there are things that can stand in the way of this intrinsic value.  Walls that make themselves present people that nay say and suck the life from you.  
In my own career I see a lack of intrinsic value in education, partially because it is free and partially because no one set them up to see the value of education, and really it’s not education at all, rather the application of education. The utility of education is what gives it value, vocab and textbook are limited because they only hold information.  What makes information beautiful is when it becomes a process and hardened idea.   The problem with this passion and the flame in and how it consumes is once it becomes stagnant once it loses its nature of engulfing and immersing those around it. This passion becomes dogma and devoid of purpose it becomes hardened and loses its almost fluid and expansive catalyst, or viral tendency.  People say “I have trouble with motivation.” or, I’ve also heard “What is the point,” ,and/or “why?”  In my mind I have had the same questions.  I struggle with motivation, but find that it is a matter of who you expose yourself to that will help you or directing your energy to completion.  My reply to “Why?” is “WHY NOT!!!”  Because when it comes down to it, intrinsic value, and passion are something you have to find for yourself.  I don’t think “give a shit” can be taught it has to be learned.
I think this is also a good article on the subject
http://www.strengthsensei.com/the-myth-of-discipline

“WOD” are you doing and the Art and Science of Auto Regulation Training Part 2

As discussed in part 1 there is a way in which training can become a bit to helter skelter, and too much chaos. Sometimes you want to train a different style, sometimes you want to add some variation to training, sometimes you are fried and can’t train well, other times you have to work around an injury a sick kid or what life is throwing at you at the moment. All of these things can add to the variation or training and end up just becoming a spinning wheel where you are not making successful gains or progress and may end up going backwards if not provided the right stimulus.
In part one of this article I brought your attention to the much needed use of progressive overload as a principal when dealing with a Crossfit COs recommendations for a WOD. Today I want to address another training style that can posit similar spinning wheel problems. It is known as auto regulation which is basically training instinctively often a result of one of the above variables that dictate training time which can limit stimulus. Now I’m not saying that Auto Regulation is better than having a program, but in some case scenarios, “The best laid plans of mice and men often go awry”. So the question invariably is: “How do I make it work?” The main answers are follow:

1.) Prioritize the A set or Main Lifts
2.) Have a track record or Personal bests and total cumulative volume on key lifts
3.) Have a goal and a time line to achieve a goal compete in a competition or tell a friend your plans.
4.) Look in past journals to establish week’s volume in tonnage on certain lifts Bsquat/Deadlift/Fsquat/ Presses /Pulls or Rows
5.) The first lift is the main lift with the most bang for your buck. You don’t want to do pushups or pistols squats, but rather what will recruit and fatigue the greatest number of motor units in the least amount of time. So Squat variations/deadlift variations/and any press variations/or pull up variation will be best.
These are generic examples interpretation would be unrealistic when comparing ratios and deficits

Compound Lifting Groups

Tonnage @ 1-3 @6-8

Date

Lift Rep maximums 1,3,5,7

Date

Posterior Chain (Glutes Hams Erectors)

Deadlift (12000)

RDL Week (10000)

RDL Day (6000)

Deadlift 315X1

Deadlift 300X3

Romanian Deadlift 265X5

Anterior Chain (Quads)

Fsquat Day (4000)

Bsquat Weeks (8000)

Fsquat 265X1

Bsquat 305X1

Upper body Presses

(Chest Shoulders Tris)

Inc Bench (3000)

Bench  (4000)

Inc 245X1

Bench 265

Upper body Pulls

Chin up (4500)

Pullup (3500)

Chinup 75+BW X2

Pullup 50+BW X1

Bicep

Inc DB Curl (1125)

 50X3

 Tricep

CG Decline Bench

(7875)

 265X1

 By having your weeks tonnage as a lifter you can modify frequency to prioritize a lift and a specific volume. Understand that deadlift is back squat and back squat is not front squat when it comes to tonnage they can both play into tonnage/cumulative volume, but the greater tonnage with rom will likely carryover best to achieving progressive overload.

On a similar topic, this may be why when you train DB work in the place of barbell work it can be hard to achieve direct carry over unless specific tonnage/volume stimulus is met at least this is a theory of mine. The body may not respond to submaximal loads without increased volume of sets or reps.
An example would be:
Phase 1.) Incline Press 225 6X5 = 6750 (accumulation)
Phase 2.) Incline DB Press (95+95) 5×3 = 2850 (intensification)
Doing the math you can see about a 4 thousand pound deficit, so can the body hypertrophy? Yes, but it may not carry over as well to barbell press unless you increased sets at, or greater than the volume/tonnage seen with the barbell, or better still prioritize barbell on intensification, and dumbell on accumulation phases. From my vantage the above would create a type of peaking for DB work or detraining depending on your perspective. That being said you can and will get stronger on DB press when using progressive overload. This however is a theory of mine and is a point of contention between myself, and a colleague of the iron game. This is partially why I think Undulating periodization is better at producing hypertrophy than linear periodization.

That being said you can and will get stronger on DB press when using progressive overload, but it could but in my mind would be considered a misstep when approaching progression in the above fashion unless correct stimulus is created. I would suggest testing the theory out, also understandably DB and BB work are often complimentary to one another and would be best if were done together rather than separately.

In conclusion, I hope that this provides you the reader with a better understanding of progressive overload when trying to make gains and deal with what life throws at you.

Kata and the Automaton’s Tempo

In the book Outliers Malcolm Gladwell brings up the principal of 10,000 hours of practice to be a master. In the book Linchpin by Seth Godin describes the idea of being indispensable due to talent related to practice. In the book Mastery Roberte Greene helps define how it is certain people in history become masters. I think each are brilliant books and all demonstrates how with repetition people become better as they become more specialized at their craft. Slowly they whittle away at their task blowing away the chaff, chipping away imperfection and soon brilliance surfaces and even some times genius.

It is interesting to me in my past I worked at a factory out of high school. The factory made books and we would box and ship these books off to schools, and wherever. A machine would spit out books in a stack and we would have to open a box in a certain manner and envelop a paired stack of books in the box, then fold the ends over, flip the books and the box, then fold the top’s ends down and finally push the boxed books onto the conveyor belt for the taping machine to do it’s job. The hard part was learning the procedure when first hired on. You had to wait your turn behind a proficient boxer of books so not to mess up the machine. It was overwhelming to be expected to box books at the rate that the machine spit them out, but the experienced employee could do it effortlessly. The best way I can describe the way you box books is probably a lot like when you hit a wing chun dummy in a certain pattern. There was a feel and a cadence much like everything else it became easier with practice. After a year at the place and some heavy caffeination we would challenge our coworker on the opposite side of the machine to see who was the fastest at boxing books.

In the world of exercise there as always, are multiple upon multiple repeated tasks it reminds me of the karate kid and how the master taught the student how so many things that we do when paying attention to the subtle details have a purpose in a bigger picture. In exercise as you get better you feel positions you have trained over and over again, and their isometric ranges lock into position efficiently and often look effortless to the observer. On the jerk if mechanics are correct you can feel everything snap into position. In the clean you can feel the symmetry of the bar as you receive and your heels dig into the floor. In grappling each move and position that you have rehearsed are easily reprocessed and the feel of the position lock to a posture that is stable. In boxing there is the feel of the right contact in a well-executed combination of punches. In baseball the sweet spot on the bat or in tennis the feel of the perfect return. In basketball the feel of the ball leaving your fingertips and the certainty of it’s trajectory. All of these things are built in rehearsal and repetition. Each pattern is defined by a specific feel. This feel takes a long time for people to be aware of it without repetition.

It is interesting to me in my past I worked at a factory out of high school. The factory made books and we would box and ship these books off to schools, and wherever. A machine would spit out books in a stack and we would have to open a box in a certain manner and envelop a paired stack of books in the box, then fold the ends over, flip the books and the box, then fold the top’s ends down and finally push the boxed books onto the conveyor belt for the taping machine to do it’s job. The hard part was learning the procedure when first hired on. You had to wait your turn behind a proficient boxer of books so not to mess up the machine. It was overwhelming to be expected to box books at the rate that the machine spit them out, but the experienced employee could do it effortlessly. The best way I can describe the way you box books is probably a lot like when you hit a wing chun dummy in a certain pattern. There was a feel and a cadence much like everything else it became easier with practice. After a year at the place and some heavy caffeination we would challenge our coworker on the opposite side of the machine to see who was the fastest at boxing books.

All this being said each lift, posture and pattern can become drudgingly monotonous as you concentrate on getting a certain number of repetitions with a specific weight in order that you can make the gainz that you have planned. The problem is with reps often it is forgotten to feel. In the past I have explained how a bodybuilders focuses on the feel of the movement and it’s mechanics within the muscle though I think sometimes new people get used to the rep and less concerned about the feel of the position. When you get used to the feel you will notice the subtle pattern differences of each rep and the predisposition of some muscles to override the pattern due to fatigue. As you get to the end of your rep range.

Enter the use of Tempo. Tempo is probably not something that is needed for exercise though it is a variable of training that allows you to exploit the eccentric range of a lift with greater proficiency than on the concentric due to eccentric strength being superior to concentric. Isometric strength is also greater than concentric strength so it is another variable to utilize on the eccentric and sometimes the concentric. When and how to exploit these vairaibels of a rep involve pauseing with submaximal weight in the position you are weakest at on a lift. On the eccentric focusing on decelerating within the weakest range of motion is another way. Tempo is also a way to all a new client to not just look like a pneumatic oscillating machine that has no defined pattern. The basics of tempo are as follow 4 numbers define the speed of the lift.

51X2

The first number 5 defines the speed of the eccentric or negative when the agonist muscle group is lengthening

The second number 1 defines the pause or isometric at the least advantageous position on bench or deadlift at the bottom where you are weakest on pullup at the top when you are over the bar where you are weakest.

The third number X is the concentric or positive where you are accelerating the bar as fast as you can.

The fourth number is the 2 where you isometrically pause at the most advantageous position.

I believe Ian King is the originator of TEMPO feel free to correct me if I am wrong but he used 3 numbers to define the cadence. There are ways you can modify, or accentuate positions with a pause at varying locations. There is also the use of the isometric against a relatively immovable object to strengthen a sticking point. All that being said, I believe the tempo helps define the speed of the Kata that is an exercise. When you get good at a pattern you will know by feel of your symmetry, when your scapula is in the proper position, where your heal are what your neck is doing and over all, how technical the rep is. Until you pay attention to the subtlety of feel, or Fingerspitzengefühl (borrowed that from the book 48 Laws of Power) It will be hard to understand the Kata.

“WOD” are You Doing or The Schizophrenic Training Dilemma Part 1

By now you may have heard of Cross Fit.  There has been a great divide between people of all backgrounds in the fitness community in the beginning a lot of people hated it, and would not accept it in the fitness world.  It kind of reminds me of the story of Joseph in the bible.  As a practitioner of strongman, powerlifting, and Olympic lifting and a personal trainer.  I’ve decided to give you my take on this amalgamation of a discipline, as I think there is much to be learned.  Now before I go into this I just want to say I am mainly against Crossfit COs programming as I do know of Crossfit gyms that actually utilize the sacred arts of progressive overload.

One of the biggest criticisms of the Crossfit is the idea of a WOD (Workout of the day).  Looking closely at the Crossfit website I can attest that there is a lot more madness than method. I have on multiple occasions tried to decode the cypher that was there periodization style on the main Crossfit site, but to no avail.   From my vantage it was madness and not in a Spartan kind of way.  However the beauty of Crossfit is it practically incorporates everything related to fitness from running, to gymnastics, to Olympic lifting.  This is practically the entire gamete outside of a winter games type scenario.

The limiting factor unfortunately will be dictated by the person that owns the “box” or gym dependent on what vernacular you want to use.  If the gym owner is an Olympic lifter they will likely, through process of least resistance, make the WODs predominately Olympic lifting style.  They will likely be good at periodizing a training plan that will progress you to greater strength in the movements along with squats and a variety of deadlift styles.   If they are or were a runner in their past they will likely schedule a lot of running in their training and so on.

Now all of the above being said what you have to understand is there are a lot of great strength and skill coaches in cross fit gyms/boxes.  However there is also a lot of gyms and boxes that have a limited understanding of progression and periodization.  The experience of coaching and competing will teach some of them.  Often they are passionate and have your interest in mind, but in some instances are a noob to progression.

The best competitors of crossfit tend to be the strongest, what that means is if you want to be a great competitor in crossfit it is in your best interest is to become stronger.   Usually they design training out of season around strength and minimize WODs that they do so they can maximize strength.  Balancing priorities of strength will be the greatest way to dictate your success.  A long time ago my dad went on a tyrade about how I wasn’t writing my training notes down, I think the same it true for any person hoping to become stronger you have to pay attention to the variables that relate to progressive overload or you are spinning your wheels.  Week to week if you are not tracking increases strength training becomes schizophrenic.  So have a goal and have a plan to achieve that goal.  If it’s a chin up figure out what you need to do to achieve that mile stone and then determine what you will do when you get there.  In this way priority will dictate training volume and frequency.

When looking at training design a good strength coach will have practitioners do strength work first so that met cons or WODs don’t interfere with the most important variable of progress which is strength as it will carry over to muscular endurance.  Another option would be to space recovery or a WOD with strength training so that you can recuperate before strength training.  Here are some examples

Mon

Tue

Thur

Fri

Mon

Tue

Thur

Fri

Bsquat

5X5

Strict Press

5X5

Fsquat

5X3

Hang Clean

5X3

Bsquat

5X5

Strict Press

5X5

Fsquat

5X3

Hang Clean

5X3

Pullup

3X8

Pendelay Row

3X8

Jerk

5X3

RDL

3X5

Pullup

3X8

Pendelay Row

3X8

Jerk

5X3

RDL

3X5

Grace

Skill

Elizabeth

Helen

Grace

Skill

Elizabeth

Helen

Understand you will need a minimum of 2 weeks to test for strength gains otherwise it becomes less of a science and more of variety hour.

In conclusion Crossfit is great for all fitness types and all categories or training, but training design and the extent of the coach’s background will dictate if he or she is a good coach or a great coach. These things don’t happen overnight.  It is hard to be a jack of all trades because you may be cursed to be a master of none.   I want to be clear this is article is directed to people that are new to fitness not experienced competitors.

Calculator

Still in process of working out the bugs

Description

Weight:
Body Fat %:
Age:

BFtwo LBM BMR- BMR+
  Mon Tue Wed Thur Fri Sat Sun
Protein
Carbs
Fat
Calories

 

Internally Rotating Origami or The Collapsible Vitruvian Man

When you watch powerlifters squat and deadlift you can see a unique difference in the styles of a squat.  The upright position of the Olympic lifter stands out in my mind.  Where the powerlifter conforms to a more forward leaning position.   A mechanically similar movement with the same name, but a subtle and unique variance of the similar pattern.  High bar vs low bar squatting may create an argument,however you can see high bar squatters who demonstrate low bar squatting technique when fatigued.   Failing in a squat or squatting in fatigue generally follows a similar pattern more similar to a powerlifters technique.

I’m reaching here, but if you have seen the mars rover and how they packed it tight into the shuttle so it would take up as little room as possible and still be able to unfold itself upon arrival, you can see a similar concept from a baby in fetal position.  The body structural mechanic tendency is to collapse toward this internally rotated position.  This parallels with fatigues ability to internally rotate a body into it’s structurally weakest position.  When you squat fatigue tends to internally rotate your hip when you bench fatigue flares your elbow so you can internally rotate your shoulder.  These examples aren’t unique they are the body’s natural tendency.

The powerlifter has mechanically strengthened a more internally rotated position by racking the bar low and allowing the position to internally rotate his shoulder and flex his hip into lordosis.  Where you will find the Olympic lifter removes the lordosis at the top of his squat an moves to hip extension you will also find a tendency for the Olympic lifter to have elbows further under the bar and less internally rotated shoulders.  Neither of the styles are incorrect because both are conforming to the sport.  However longevity would favor the Olympic lifters posture, but structurally the body will always internally rotate when at maximal weight or in a fatigued state.

Within an adaptation cycle to a lift there is also a latent tendency to assume a more efficient internally rotated posture.  In a front squat sometimes the body finds a way to inhibit muscles in order to fire active muscles more efficiently.  I believe this is where people with mechanically correct front squat tend toward wrist pain, because they relax the hand on the bar. Relaxing the wrist flexors on the bar so the body relies on tendon and ligament of the wrist rather than muscle to maintain joint integrity.

Integrity of a movement pattern can also be hampered by muscle belly length distortion. You will find that the the bodies feedback computer system pays attention to length tension and various and other stimulus.  The duration of a length tension can hinder efficiency of a contraction.  The problem is sometimes in order to understand information individuals make up things like muscle activation work which is a good concept, but some authors have criticized the verbiage because the idea assumes that the muscle is inactive and you are activating it.  The problem is at certain lengths the muscles activity is irrelevant because it doesn’t efficiently provide tension when needed in a movement pattern.  The glutes in opposition to the abductor and hipflexors are a large part of the issue from this stand point.  So sitting for a long duration will lengthened glutes is a compromised position making glutes become slack. This slack creates a greater reliance on other muscles to maintain optimal position in a movement pattern. So rather than not being “activated” they are rather inefficient at the length when they are engaging along with hipflexor and adductor being short and tight.

Long story short I think this is the reason that lifting legs 2 to 3 days in a row or any lift for that matter will allow for more efficient presses and or squats so long as volume is divvied up into frequency that is not much greater than a single day.

Hickory Dickory Dock or Nutrient/Meal Timing/Yin and Yang

received_10208435650709420Morning joe has been morning staple for a while.  People have used coffee to help them when they lack sleep and people have used coffee when they need to pull an all nighter or even to prep for a end of day workout.  So when people need to wake up typically they reach for coffee or tea even.  Now before the ritual of the morning joe became common place Chinese medicine used the concept of yin (water) and yang (fire) these two concepts work in a sort of harmony or balance, an equilibrium.   Though the concepts seem distinct from today’s science we have hours of wakefulness (yang) and hours of sleep (yin).  I don’t claim to be a traditional Chinese medicine person only to understand the concept weakly.  So for example if you were to yin in the morning they would introduce something yang like coffee.  Forgive me any TCM practitioners if I over step here.  I am going to do a little bit of reaching here.  Carbs can function in a similar fashion as coffee and by introducing carbs in the AM you will be more likely to crash in the AM due to blood sugar fluctuation.  What tends to happen is the carbs burn fast vs fats which are slower burning.  In a lot of instances eating more fat and protein in your breakfast can be beneficial.  (1)(2)(3)(4)  The direct effect seems to be satiety you can function longer without having hunger pangs on higher protein lower carbs.

Enter caffeine into the mix of a meal and you will find that in some instances it can increase uptake of carbohydrates post exercise, however in other instances it lowers insulin sensitivity.   Muscle Glycogen can be restored in around 20-24 hours depending on the study and frequency of carbohydrate consumption. However Protein requirements for muscle have to be within the first 36 hours and since they body can’t assimilate all of the protein it is often best spaced every 3-6 hours (8)

This is my generalized version for a better understanding consult the study

Pre workout Fail safe method  Workout Post workout fail safe method
Protein 1hrmin 20-40g Pre WO 45-90 minute WO 30-60 min 20-40g Post W0
Carbs Preferably minimal pre Would depend on volume (8)(9)(10)
Fat 5-15g

(WO) workout

 

(1.)http://ajcn.nutrition.org/content/83/2/211.ful

(2.)http://ajcn.nutrition.org/content/82/1/41.full

(3.)http://ajcn.nutrition.org/content/87/5/1558S.long

(4) http://www.ncbi.nlm.nih.gov/pubmed/15042132

(5) http://www.ncbi.nlm.nih.gov/pubmed/10953755

(6) http://www.ncbi.nlm.nih.gov/pubmed/24787031

(7) http://www.jissn.com/content/10/1/5

(8) http://www.ncbi.nlm.nih.gov/pubmed/21116024

(9) http://jap.physiology.org/content/93/4/1337

(10) http://www.ncbi.nlm.nih.gov/pubmed/17095924