When determining the value of an assistance exercise for weightlifting, speed specificity, the velocity at which a movement takes place, is crucial (1,3,9). In addition, the principle of overload must always be taken in to account, the need for both specificity and variety must be balanced, the individual needs of each athlete must be considered, and the sport must be fun if the right combination of competitive lifts and assistance exercises is to be found.

Full Article at: weightliftingexchange.com

Written by Chris LeRoux

Valsalva maneuver

From Wikipedia, the free encyclopedia

The Valsalva maneuver or Valsalva manoeuvre is performed by forcible exhalation against a closed airway, usually done by closing one’s mouth and pinching one’s nose shut. Variations of the maneuver can be used either in medical examination as a test of cardiac function and autonomic nervous control of the heart, or to “clear” the ears and sinuses (that is, to equalize pressure between them) when ambient pressure changes, as in diving or aviation.

The technique is named after Antonio Maria Valsalva,^[1] the 17th Century physician and anatomist from Bologna, whose principal scientific interest was the human ear. He described the Eustachian tube and the maneuver to test its patency (openness). He also described the use of this maneuver to expel pus from the middle ear.

A modified version is done by expiring against a closed glottis. This will elicit the cardiovascular responses described below but will not force air into the Eustachian tubes.

Contents [hide] 1 Physiological response 2 Normalizing middle-ear pressures 3 Cardiology 4 Neurology 5 Valsalva retinopathy 6 See also 7 References 8 External links

[edit] Physiological response

The normal physiological response consists of 4 phases, which are marked on the figure at right:^[2]

1. Initial pressure rise: On application of expiratory force, pressure rises inside the chest forcing blood out of the pulmonary circulation into the right atrium. This causes a mild rise in stroke volume.
2. Reduced venous return and compensation: Return of systemic blood to the heart is impeded by the pressure inside the chest. The output of the heart is reduced and stroke volume falls. This occurs from 5 to about 14 seconds in the illustration. The fall in stroke volume reflexively causes blood vessels to constrict with some rise in pressure (15 to 20 seconds). This compensation can be quite marked with pressure returning to near or even above normal, but the cardiac output and blood flow to the body remains low. During this time the pulse rate increases.
3. Pressure release: The pressure on the chest is released, allowing the pulmonary vessels and the aorta to re-expand causing a further initial slight fall in stroke volume (20 to 23 seconds) due to decreased left ventricular return and increased aortic volume, respectively. Venous blood can once more enter the chest and the heart, cardiac output begins to increase.
4. Return of cardiac output: Blood return to the heart is enhanced by the effect of entry of blood which had been dammed back, causing a rapid increase in cardiac output (24 seconds on). The stroke volume usually rises above normal before returning to a normal level. With return of blood pressure, the pulse rate returns towards normal.

Deviation from this response pattern signifies either abnormal heart function or abnormal autonomic nervous control of the heart. Valsalva is also used by dentists following extraction of a maxillary molar tooth. The maneuver is performed to determine if a perforation or antral communication exist.

[edit] Normalizing middle-ear pressures

When rapid ambient pressure increase occurs as in diving or aircraft descent, this pressure tends to hold the Eustachian tubes closed, preventing pressure equalization across the ear drum, with painful results.^[3][4][5]caisson workers and aircrew attempt to open the Eustachian tubes by swallowing, which tends to open the tubes, allowing the ear to equalize itself. To avoid this painful situation, divers,

If this fails, then the Valsalva maneuver may be used. It should be noted this maneuver, when used as a tool to equalize middle ear pressure, carries with it the risk of auditory damage from over pressurization of the middle ear.^[4][6][7][8] It is safer, if time permits, to attempt to open the Eustachian tubes by swallowing a few times, or yawning. The effectiveness of the “yawning” method can be improved with practice; some people are able to achieve release or opening by moving their jaw forward or forward and down, rather than straight down as in a classical yawn.^[4] Opening can often be clearly heard by the practitioner, thus providing feedback that the maneuver was successful.

During swallowing or yawning, several muscles in the pharynx (throat) act to elevate the soft palate and open the throat. One of these muscles, the tensor veli palatini, also acts to open the eustachian tube. This is why swallowing or yawning is successful in equalizing middle ear pressure. Contrary to popular belief, the jaw does not pinch the tubes shut when it is closed. In fact, the eustachian tubes are not located close enough to the mandible to be pinched off. People often recommend chewing gum during ascent/descent in aircraft, because chewing gum increases the rate of salivation, and swallowing the excess saliva opens the eustachian tubes.

In a clinical setting the Valsalva maneuver will commonly be done either against a closed glottis, or against an external pressure measuring device, thus eliminating or minimizing the pressure on the Eustachian tubes. Straining or blowing against resistance as in blowing up balloons has a Valsalva effect and the fall in blood pressure can result in dizziness and even fainting.

[edit] Cardiology

The Valsalva maneuver may be used to arrest episodes of supraventricular tachycardia.^[9][10] The maneuver can sometimes be used to diagnose heart abnormalities, especially when used in conjunction with echocardiogram.^[11] For example, the Valsalva maneuver classically increases the intensity of hypertrophic cardiomyopathy murmurs, viz. those of dynamic subvalvular left ventricular outflow obstruction; whereas it decreases the intensity of most other murmurs, including aortic stenosis and atrial septal defect.

Effect of Valsalva	Cardiac Finding
Decreased
	Aortic Stenosis
	Pulmonic Stenosis
	Tricuspid Regurgitation
Increased
	Hypertrophic cardiomyopathy, mitral valve prolapse

The Valsalva maneuver alters heart rate through parasympathetic stimulation (i.e. the vagus nerve, cranial nerve X). Vagal neuro-muscular junctions at the sinoatrial node release the neurotransmitter acetylcholine (ACh). Ligand-receptor binding causes several effects:

1. ACh lowers the permeability of muscle cell membranes to sodium and calcium ions, resulting in a slower rate of pacemaker depolarization. Hence, the cell takes longer to generate an action potential.

2. ACh also lowers the number of available L-type calcium channels, which elevates the cell’s threshold for action potentials. Thus, the cell needs to depolarize more than normal to fire an action potential.

3. New research suggests that ACh also activates latent potassium channels in the cell membrane. Increased potassium ion influx decreases the maximum diastolic potential of the cell. That is, hyperpolarization decreases the membrane potential of the pacemaker cells.

These effects elongate the time between pacemaker action potentials, which results in a slower heartbeat and a mechanism to interrupt or diagnose arrhythmia. In later phases of the Valsalva maneuver (phases II and III), heart rate elevates due to sympathetic interplay.

[edit] Neurology

The Valsalva maneuver is used to aid in the clinical diagnosis of problems or injury in the nerves of the cervical spine.^[12] Upon performing the Valsalva maneuver, intraspinal pressure increases. Thus, neuropathies or radicular pain may be felt or exacerbated, and this may indicate impingement on a nerve by an intervertebral disc or other part of the anatomy.

[edit] Valsalva retinopathy

A pathologic syndrome associated with the Valsalva maneuver is Valsalva retinopathy.^[13] It presents as preretinal hemorrhage (bleeding in front of the retina) in people with a history of transient increase in the intrathoracic pressure. The bleeding may be associated with a history of heavy lifting, a forceful coughing, straining on the toilet, or vomiting. The bleeding may cause a reduction of vision if it obstructs the visual axis. Patients may also note floaters in their vision. Usually a full recovery of vision is made.

[edit] See also

• Ear clearing

[edit] References

This orthopedic test also can be a positive for a SOL/ space occupying lesion, e.g. Tumor (benign or malignant), clot, or anything taking up space where there is normally no space to be occupied.

Active Hip 2.0: The Directors’ Cut
by
Mark Rippetoe and Stef Bradford

This article was written for the single purpose of exploring Bulgarian training methods as they can and should be used by your run-of-the-mill American weightlifter. Well, that and for the purpose of firing off a little rant. But, if you can get through the ranting, I promise there will be some training stuff somewhere in there…

As of late, it seems that an increasing number of people have taken to saying that the Bulgarians have lost their edge, and that Bulgaria is ‘no longer dominant’ in international weightlifting. I am not altogether sure exactly what results these folks are looking at. The 2000 Olympics, for example, which was about the worst meet in 3 decades for the Bulgarians, still saw 4 Bulgarian-trained lifters on the medal stand. Six students of the Bulgarian system medalled at the 2002 World Championships. As of March 2003, if one were to look at the IWF men’s rankings one will find that the Bulgarians have a lifter ranked in the top 3 in ALL SIX classes that are 69 kilos and above. Not only that, but in 4 of those classes the Bulgarian is ranked number one.

So, it seems to me that in the ‘ever-expanding world of the 21^st century’, the Bulgarians are continuing to more than hold their own in weightlifting. Especially when one considers that Bulgaria is a nation of about 8 million, while countries of half a billion sit and flounder with no lifters and no medals.

But I digress… the fact is that the Bulgarians are still good. They are better than good. And the single most important reason for their success is their training methods.

Yes, after comments about how the Bulgarians are not that good anymore come out of one side of the mouth, comments about how their training is worthless usually comes out of the other. The most common version of this old song and dance is a statement to the effect of “Oh, that routine would KILL you!” Inherent in this excuse is one of two common premises. First is that the Bulgarians succeed with their training solely because of enormous amounts of drugs. Second is that only their hand-picked genetic freaks could handle that kind of workload.

The problem with the first point is that the Bulgarians are not that high on the list of IOC drug offenders. Sure, there are Bulgarians that use banned anabolic substances. But, the same can be said for EVERY international team, and I do mean *EVERY*. The fact is that the Bulgarians dominate the middleweight classes, where excessive use of anabolics might just put a lifter over his class limit. Some countries which will remain nameless, for instance Russia, always seem to have their best lifters drifting through the 94s and the 105s on their way to being 135 kilo heavyweights. This type of situation seems much more indicative of drug use, but of course the whiners do not want to hear logical arguments. Additionally, the Bulgarian training system is not the type that would draw too heavily upon the benefits of using anabolics. The Bulgarian-type workout consisting only of a moderate number of not-quite-maximum singles imposes a heavy burden on the CNS, but if one is looking for CNS stimulation or recovery there are better places than steroids to find it. Again, contrast this with traditional training programs in the Russian regime where athletes of high sports mastery would be training on up to 80 different lifts/exercises a year, with about 25% of these done for sets of 5 reps or more, and you can see a training protocol that drastically has its effectiveness increased by substances that will increase protein synthesis and help recovery at the cellular level.

The second point, that of genetics, has a grain of truth in it. The best Bulgarian lifters have been in the system for quite some time, and have risen to the top from among the best of the best. However, one can look down the Bulgarian ranks to see if it is the ’system’ or the ‘individuals’. Bulgaria usually has a very deep team of lifters, so much so that they can afford to sell half of them to foreign countries. I somehow doubt that, again, in this nation of only 8 million people there are that many more ‘perfect weightlifters’ born than anywhere else. The other thing is, these lifters have slowly worked up to what they are doing over that long time that they have been in the system. Bulgaria does not throw its 14 year-olds into a situation where they go from doing nothing to doing 27 workouts a week where they snatch to a heavy single. In fact, many Eastern European nations that start lifters as young as 12 years old have them doing only about 30% of their training as specific preparation for as long as 3 years. It takes them a long time to ramp up to the volumes they are handling once they are competing at the world level.

Finally, as an adjunct to both points, people need to realize that the training program, as the elite Bulgarian lifters follow it, IS brutal. However, drugs are not as big a piece of the pie as they are made out to be. Neither is genetics. The Bulgarians have massages before, during, and after workouts. Do you? The Bulgarians take all sorts of herbs and ‘adaptogens’ and are deeply involved in legal sports performance pharmacology. Are you? The Bulgarians on the national team don’t have to keep a 9-to-5, forty hour a week job. Do you? The point here is that there are many recovery factors that can come into play that do make a Bulgarian routine more accessible to their lifters than to the average American. That said, if you are willing to do some homework on herbs and learn a little bit about sports self-massage, etc., you also can reap the benefits of increased recovery.

All that having been said, I simply refuse to accept the idea that there is nothing to learn from their training. In fact, I have arrived at what I believe is a way to work *anyone* into a system that at least draws upon the same principles as the Bulgarian training methods, and have been using it with myself and others. You might never get to ‘Full-on Bulgarian’ status, but you can definitely make their type of workouts work for you…

Step 1: Basic Routine Template

Monday:

• Snatch: 3 singles, using ‘Maximum Training Resistance’ (use matrix)
• Clean & Jerk: MTR matrix
• Front Squat: 3 singles, using MTR, then 2 doubles with MTR -15 kilos

Wednesday:

• Back Squat: 3 doubles with Monday CJ MTR + 20 kilos
• Power Snatch: 3 singles with MTR
• Power Clean and Push Jerk: 3 singles with MTR
• Romanian Deadlift: 3 triples with Mon CJ MTR + 20 kilos

Friday:

• Snatch: work up to true 1RM
• CJ: work up to true 1RM
• Front Squat or Back Squat: work up to true 1RM

[Basically this is a 'Total Day' or a simulated competition. Again, you don't want to psyche up like this is the Olympics, but you do want to 'let loose' and push yourself to darn near what your absolute max for that day would be.]

There you have it. Pretty simple, eh? And who could complain about that volume or frequency? If you cannot handle the above workout schedule, then you have some serious recovery issues. You may want to consider retiring from weightlifting and taking up cross-stitch, or something else less stressful.

Now, one of the important concepts here is that of “Maximum Training Resistance.” This is what some of you may have heard referred to as a ‘daily max’ before. The definition of the MTR is “the maximum resistance that can be overcome one time without a strong effort of will or emotional stress.” This is key in this program, at least as I have it structured to work for the individual. We want to use the MTR so as not to burn out the nervous system. Thus, on Mondays and Wednesday, the singles in the classical and power lifts must NOT be ‘balls to the wall, my youngest son is hanging suspended over a Judas Cradle’ type of lifts. They are ‘I can walk up to the bar and pull this weight’ lifts. Of course, you have to toe the line. Also, you have to learn whether you are missing lifts because you are actually working above your MTR, or because your form sucks. For me, it is an issue of pulling in the snatch and clean and the drive in the jerk. If I am pulling the bar high enough to snatch it or clean it, and driving it high enough to jerk it, I don’t feel that I have exceeded my MTR, whether I am making the lifts or not. If I am missing my snatches out front, it is likely just because of my crappy first pull and lack of a full shrug, and not because I am going too heavy. As a lifter progresses, he will learn exactly where that line is.

At the start of the program, Mondays and Wednesdays only will be done using the ‘MTR Matrix’. This matrix will appear at the very end of the article, and I will place appropriate comments with it.

Step 2: Adding a Session

Alright, the first step beyond the basic workout on your way to becoming a Bulgarian. What is it? On the middle day of the week, you are going to do 2 sessions. The session you have already been doing will be the AM session, and the following will be done in the PM:

• Snatch 80%/2 (3-4 sets)
• CJ 80%/2 (3-4 sets)
• Snatch Pulls 3-4 sets of triples with a weight 10 kilos over what was used for the snatches

The issue here becomes on what day of the week are you able to add a session. So, if you can do an AM and PM workout on Thursday, that becomes your ‘middle day’, and you are now lifting Tuesday-Thursday-Saturday. Though, if adding an AM (or basically just a session 2-3 hours earlier in the day) session is a big stumbling block, continuing on with the progression of the program might be next to impossible.

The other issue here is when to take these steps. That, I am afraid, is up to the individual lifter and/or his coach. I would say that once you have been ‘through the matrix’ a couple of times at each and are able to keep making progress, add the next step. Your body is ready for the challenge.

Step 3: Adding a Day

So, you have added a session. A few months later, you should be ready to add a fourth day. What previously would have been the M, W, F workouts, respectively, will now take place on M, Tu, and Sat. What do we add in? On Thursday, you will do a workout that looks exactly like Monday’s. That wasn’t so hard, was it?

Step 4: Adding a Session

You have now been lifting 4 days a week, twice on Tuesdays. Your hair has gotten a little longer than is stylish, and you tend to wear t-shirts bearing ’80s slogans that were not even cool in the ’80s. It is time to move on…

You will add an AM session to Monday. (with the previously done Monday session moved to the PM, or done second) What will that AM session look like?

• Snatch: 85%/2 (3-4 sets)
• CJ: 90%/2 (2-3 sets)
• Back Squat or RDL to MTR

Step 5: Adding Two Sessions

This is it. The final bump in the road. It may have taken you a year and a half to work through the prior steps. You now can answer your cell phone between the clean and the jerk portions of the lift, and you got a new driver’s license that says “?a?C?/4??” instead of “Dave Smith”. You are ready for the final step in truly becoming a Bulgarian…

What is added? It’s simple, really. On Thursday you add an AM workout that looks the same as Monday’s AM workout, and on Saturday you do the following workout (though it is more of a CNS warm-up than a workout) in the AM:

• Back Squat 80%/3 (3 sets)
• Power Snatches: ‘light’
• Power Clean and Push Jerk: ‘light’

So, there you have it. You now do 8 workouts a week. Craziness? Hardly, if you have added the steps only once you were ready. Not quite as extreme as the Bulgarians? Think again, because you are now using almost the exact same routine that the Bulgarian team has been doing since new Head Coach Plamen Asparukhov took over for Abadjiev in 2001 and reaffirmed the Bulgarian team’s commitment to staying in line with IOC doping regulations. You now train just like Boevski and Jeliazkov, so good luck and go lift like them…

*The MTR Matrix

This is basically a system of volume/intensity progression that was used by the old Bulgarian regime that has not fallen out of favor. You can play with and rearrange the weeks as you like, but my preference is to go A-B-B-C-A. Some people can handle A-B-B-C-C-A. Try different things and see what works for you.

Also, to start with a lifter is probably best off basing the entire mesocycle on the MTR that was used during the first week. So, the weeks will just build upon each other. As the lifter becomes more comfortable with the system and his own capabilities, however, he will become more in tune with what his true MTR is on any given day, and during weeks B and C, respectively, will basically just do a second wave and a third wave back up to that weight irrespective of what MTR was used during week one.

“A” Week: Predicted MTR -20kilos for 2 reps, Pred. MTR -10 kilos for a single, MTR for 3-4 singles.

“B” Week: Perform A week progression, followed by MTR -10 kilos for a double, MTR -5 kilos for a single, and then MTR +5 kilos for 2-4 singles.

“C” Week: Entire B week progression performed, followed by a double with MTR -20 kilos, another double with MTR -10 kilos, and finally 3-4 more singles with MTR plus 5 or 7.5 kilos.

So, if you were doing a simple A-B-B-C-A progression over 5 weeks, and you found that your snatch MTR was 100 on the first Monday, for the next 5 weeks your Monday snatch workouts might be as follows:

Week 1: 80/2, 90, 100 (3-4)

Week 2: 80/2, 90, 100 (3), 90/2, 95, 105 (2-4)

Week 3: 80/2, 90, 100 (3), 90/2, 95, 105 (2-4)

Week 4: 80/2, 90, 100 (3), 90/2, 95, 105 (3), 80/2, 90/2, 105 (2), 107.5 (2)

Week 5: 80/2, 90, 100 (3-4)

At this point, the lifter would start over, this time likely using 105 as the MTR for the first A week in the mesocycle.

Benefits of Olympic Weightlifting
You are probably wondering what makes Olympic Weightlifting a better choice for resistance training than others forms. Weightlifting offers many benefits over bodybuilding, powerlifting, and machines. However, the main reason people do not participate in weightlifting is because they are afraid of getting injury, however this is a false assumption that is easily discredited.

Safety and Injury Aspect of Weightlifting
Various studies were done showing Olympic weightlifting to be the safest form of resistance training there is. One study assessed the injury potential and safety aspects of weightlifting movements and Olympic weightlifting proved to be the safest (Stone, Injury). Another aspect that keeps many people away from weightlifting is the supposed fatal injury to the back. Again this is a false assumption spread through ignorance. A study was done comparing weightlifting to a control group of normal active men and their back pain was assessed. It turns out that only 23% of the weightlifters experienced back pain compared to 31% of the normal active men (Granhed). Another study was performed concerning the injury per 100 hours and yes again weightlifting faired better than other forms of resistance training. In fact, for weightlifters the injury rate was less than half of the other forms of weight training (Hamill). Weightlifting training and competitions together are much safer than other sports such as football, basketball, soccer, etc (Stone, Muscle). It is clear to see that Olympic weightlifting is an extremely safe form of resistance training and sport for people to participant in.

Body Composition Effects
Another benefit of weightlifting is the amount of muscles used in the lifts. The Olympic lifts involve basically every muscle in the human body and this entails a great workout. Olympic weightlifting also forces stabilizer muscles to activate to secure the weight overhead in the lifts. For a recreational lifter Olympic weightlifting will cut down on the exercise time, allowing them to get done in 45 minutes to 1 hour what they used to do in “traditional splits” for 1.5 hours or more! In an 8 week Olympic weightlifting program study, participants lowered their resting heart rate by 8%, lean body weight increased by 4%, fat dropped 6%, and systolic blood pressure decreased by 4% (Stone, Cardiovascular). Not only is Olympic weightlifting safe it is a great way to stay in shape too!

Athletic Ability
Another important benefit of Olympic weightlifting is it teaches the body to fire all the muscle fibers at once; to explode in a sense (not literally). An 8 week study was done showing the capability of the Olympic lifts to improve sport performance and vertical jump ability. A study was performed and a group of lifters did various Olympic lifts (High pulls, Power Clean, and Clean and Jerk), and were compared to a group using vertical jump exercises (Single and Double Leg Hurdles Hops, Alternated Single-leg Hurdle Hops, etc) and after the 8 weeks of training the Olympic weightlifting group had significantly increased their 10 meter sprint speed and their standing jump over the control group using standard vertical jump exercises (Tricoli). Similarly a 15 week study was also performed using football players and compared a powerlifting program to an Olympic weightlifting program for athletic performance. After the 15 week study was over the Olympic weightlifting group had a significant improvement in the vertical jump and 40 meter sprint over the powerlifting group (Hoffman JR). Clearly there are athletic benefits that come from incorporating weightlifting into a sport training program and similarly Olympic weightlifters are also known for developing great athletic ability.

Effect on Bone Mineral Density
Olympic weightlifting can also help prevent osteoporosis. To put it simply the greater the bone mineral density (BMD) the less chance of osteoporosis occurring. Bone mineral density measures the mineral density, such as calcium, in the bones. Calcium is also constantly being added and removed from bones and when it is removed faster than it is added then the bones become weaker and are more susceptible to fractures. Remember a solid dense bone is much better than one that looks like a honey comb! A study involving elite junior Olympic weightlifters compared their BMD, at the lower back and the neck of the femur, to an exact age group and an age group ranging from 20-39 year old men. The elite junior Olympic weightlifters BMD were found to be significantly greater then the age matched group and greater than the 20-39 year old men (Conroy). It is suggested that the high overloads of stress from Olympic weightlifting have a major influence on BMD. Again Olympic weightlifting has the ability to develop strong healthy bones that are resistant to fractures.

Enjoyment Factor
One aspect of Olympic weightlifting that people enjoy is the lifts themselves. People enjoy the feeling of the barbell being weightless as they drop underneath it or they enjoy the speed that it takes to complete the lift or maybe they just enjoy mastering a technical skill. For most people there is a larger sense of satisfaction that comes from successfully hitting a personal best in the snatch or clean and jerk than finally getting those 19 inch arms or something along those lines.

These are just some of the benefits a person can come to expect from participating in Olympic weightlifting throughout their life. Hopefully, this also cleared up the ignorance on the safety and injury aspect of Olympic weightlifting. Participating in Olympic weightlifting is a fun and enjoyable experience that everyone should get to know.

References:
Conroy, Bp, Wj Kraemer, Cm Maresh, Sj Fleck, Mh Stone, Ac Fry, Pd Miller, and Gp Dalsky. “Bone Mineral Density in Elite Junior Olympic Weightlifters.” (1993): 1103-1109. Medicine and Science in Sports and Exercise 25 (1993).

Granhed, H. et al. Low back pain among retired wrestlers and heavyweight lifters. The American Journal of Sports Medicine,16(5):530-533. 1988.

Hamill, B. Relative Safety of Weightlifting and Weight Training. Journal of Strength and Conditioning Research, 8(1):53-57. 1994

Hoffman, Jr, J Cooper, M Wendell, and J Kang. “Comparison of Olympic Vs. Traditional Power Lifting Training Programs in Football Players.” 18 (2004): 129-135. Journal of Strength and Conditioning Research 18 (2004).

Stone, M. H., A. C. Fry, M. Ritchie, L. Stoessel-Ross, and J. L. Marsit. Injury potential and safety aspects of weightlifting movements. Strength and Conditioning. June: 15-21. 1994.

Stone, M.H., et al. Cardiovascular Responses to Short-Term Olympic Style Weight-Training in Young Men. Can. J. Appl. Sport Sci. 8(3): 134-9.

Stone, M.H. Muscle conditioning and muscle injuries. Med Sci Sports Exerc. 22(4):457-462. 1990.

Tricoli, V, L Lamas, R Carnevale, and C Ugrinowitsch. “Short-Term Effects on Lower-Body Functional Power Development: Weightlifting Vs. Vertical Jump Training Programs.” 19 (2005): 433-437. Journal of Strength and Conditioning Research 19 (2005).

Advanced German Volume Training
by Charles Poliquin

400 METER TRAINING, Clyde Hart, Head Track and Field Coach, Baylor University, Waco, Texas