Happy Thanksgiving To You All

Things to avoid on Thanksgiving.

Gravy, wine, gin, scotch, beer, pie, ice cream, pototoes, grandma's green bean surprise, stuffing, cranberry sauce, apple sauce, corn, bread, soda, cake, cookies, pastries,  and over-eating.

Have a nice holiday!

Daryl

Here is the one of the oldest secrets to losing body fat. You might be surprised?


To Find Out The Secret You must email me and write this in the email:


What is the Secret?

my email address is:  dconant2004@yahoo.com


Daryl

Steve Tyler of Aerosmith Sings Amazing Grace

Exercise in The Heat and Heat Disorders

This blog entry is dedicated to Dr. Fred Morrison a Floridian. His email inspired me to write about exercising in the heat and how heat affects the body. Thanks Fred!

Exercise in The Heat and Heat Disorders

The principal means by which the body loses heat during exercise or exposure to heat are 1. Circulatory adjustments of increased skin blood flow resulting from cutaneous vasodilation, and 2. Evaporative cooling resulting from increased secretion of sweat. Internal body heat carried by the blood (circulatory convection) to the surface, where conduction, convection, radiation and particularly evaporation take place. The cooled blood then returns to the warmer core and the cycle is repeated. The body temperature changes that occur during exercise in a comfortable environment (room temeperature).  Internal or rectal temperature increases to a new level during the first 30 minutes or so of work and remains at this new level until work is terminated. AT the same time, skin temperature decreases slightly primarily as a result of increased convective and evaporative cooling. The net result of theses changes is an increase in the thermal gradient between the skin and the core, which facilitates  heat loss in the manner previously described.

In a cold or cool environment, exercise that can be maintained for an hour or more is seldom limited by an  excessive increase in internal or rectal temperature. Under these environmental conditions, nearly all the metabolic heat produced can be easily dissipated by the circulatory and sudomotor (sweating) adjustments referred to earlier. Even in sever, short term work, when heat production may well exceed the heat-dissipating  capacity made possible by these adjustments, exhaustion usually results from the buildup of anaerobic metabolites (mainly lactic acid) before rectal temperature can reach a limiting or dangerous level. The elevation of rectal temperature during exercise, although proportional to the intensity of work (and therefore to metabolic rate), is independent of environmental temperatures ranging from cold to moderately warm.

Exercise In The Heat

As stated earlier, environmental heat reduces the thermal gradient between the environmental and the skin surface, and between the surface and the body core, thus imposing an added resistance to body heat loss. We have seen that body heat can actually be gained when the temperature of the environment is greater than that of our skin. By the same token, increased humidity imposes a heat-loss barrier to the evaporative mechanism by decreasing the vapor pressure gradient between moisture in the air and the sweat on our skin. Such a heat-loss barrier cause an excessive increase in rectal temperature and severely limit’s the capacity for work. 

Circulatory System and Sweating Mechanism

The reduced thermal and vapor pressure gradient of hot, humid environments greatly increase the demands placed on the circulatory system and sweating mechanism.  This is evidenced by greater increases in heart rate and sweating during exercise in hot as compared to cool environments. More blood must be circulated and more sweat secreted by the sweat glands to lose any given quantity of heat. Note should  also be made of the effects of hot, dry environments on the magnitude of these receptors. Even though the temperature is high, the low relative humidity considerably reduces the heat stress because evaporation of sweat is more efficient. The major circulatory demands while working in the hear are 1. A large blood flow through the working muscles to provide for the increased respiratory exchange of o oxygen and carbon dioxide, and to carry away the increased heat produced there, and 2. As previously indicated, a large skin blood flow to cool the blood and supply the sweat glands with water. 

Water and Salt Requirement

The high sweat rates required for adequate evaporative cooling during exposure to heat (.5 to 2.0 liters per hour) can lead to excessive losses of water (dehydration) and of salt and other electrolytes. When this occurs, work performance and tolerance to heat are greatly reduced; hypothermia (excessive internal body temperature) with predisposition to serious heat disorders is imminent.

The most serious consequence of profuse sweating is loss of body water. This leads to a decrease in blood volume and, if sever enough, to a decrease in sweating rate and evaporative cooling. The decrease in blood volume an evaporative cooling, in turn, cause added circulatory strain with eventual circulatory collapse and an excessive rise in rectal temperature. The best replacement fluid is one that contains as much salt and water as is lost through sweating, that is, about 1 to 2 grams of salt per liter of water. Several such types of replacement fluids-- which have been flavored for palatability -- are available commercially, Gatorade, smart water, function water, vitamin water are some examples. When these liquids are used, salt tablets should never be taken. Salt tablets should not be taken by athletes unless a clinical test shows an electrolyte imbalance. Fluids should be administered during as well as after prolonged work bouts in the heat. Adequate hydration by voluntary intake (thirst mechanism) alone takes several days. Therefore, during day to day heat exposures it might be necessary to insist on the drinking of some liquid even though there is no apparent thirst.

Heat Disorders In Athletics

The seriousness of overexposure to heat while exercising is exemplified not only by a decrease in work performance, but also by a predisposition to heat illness. These disorders are categorized in ascending severity as 1. Heat cramps, 2. Heat syncope, 3. Heat exhaustion-- either salt-depletion or water depletion, and 4. Heat stroke. Special note is made of the possibility of exercise induced hypothermia.. Exercise induced hypothermia is relatively rare, but does occur. 

1. Heat cramps: Heat cramps are characterized by muscle spasms or twitching in the arms, legs and possibly, abdomen and usually occur in the unacclimatized individual.

2. Heat syncope: Heat syncope is characterized by a general weakness and fatigue, hypotension (low blood pressure), occasionally blurred vision, pallor (paleness), syncope (brief loss of consciousness), and elevated skin and core temperature. Heat syncope usually occurs in the unacclimatized.

3. Heat Exhaustion (Water Depletion). Water-depletion heat exhaustion is characterized by reduced sweating, although there is a large weight loss, dry tongue and mouth (“cotton mouth”), thirst, elevated skin and core temperature, weakness, loss of coordination, and dullness. Another sign is that the urine is very concentrated and almost an orange color. Water depletion heat exhaustion can occur in the acclimatized individual.

4. Salt-Depletion Heat Exhaustion. Salt depletion heat exhaustion is characterized by headache, dizziness, fatigue, nausea, possible vomiting and diarrhea, syncope, and muscle cramps. Salt-depletion heat exhaustion is slow acting  in that it usually takes 3 to 5 days  to develop. It can occur in an acclimatized individual.

5. Heat Stroke: I cannot emphasize the following too much. Heat stroke is a life-threatening medical emergency. The sweating mechanism has become fatigued although some sweating may still be occurring. Additionally, there are elevated skin and core temperatures (core temperature may well exceed 105 F or 40.5 C), muscle flaccidity involuntary limb movement, seizures and coma, vomiting and diarrhea, and tachycardia (rapid shallow heart beat). The individual may be irrational and hallucinating if not in a coma. Heat stroke may occur to any individual under the proper conditions. The appearance of any one of these procedures begun immediately. The athlete should never be left alone to “rest”. 

The most common denominater for all these conditions are 1. Heat exposure, 2. Loss of water and electrolytes, and 3. Heat storage, usually reflected by a high core temperature (hypothermia). However, the single most important factor, from a clinical stand point is loss of body water. Inattention to heat cramps, heat syncope, and heat exhaustion can lead to heat stroke and finally to death because of irreversible damage to the central nervous system. Even in those who do recover from heat stroke there often is some permanent damage to the thermoregulatory center in the hypothalamus. As a result of this damage, the hypothalamus loses some of its integrity or ability to regulate body temperature. This leads to decreased heat conductance form the body core to the periphery and explains why many who have survived heat stroke are more prone to future heat disorders. 

Normally, a person will voluntarily stop working and seek shelter from the heat when cramps, heat exhaustion, or syncope sets in. However, highly competitive athletes are more vulnerable to heat disorders in general and heat stroke in particular for several reasons 1. They are highly competitive (motivated) and therefore more likely to overextend themselves, 2. They have a sense of immortality 3, they sometimes are required to wear heavy protective equipment, which adds resistance to heat dissipation by reducing available evaporative surface, and 4. Incomprehensible as it may seem, the coach may deny the athlete water during prolonged contests or practice sessions, which lowers their resistance to heat tolerance. These factors, either singularly or combined, are as pertinent to environmental conditions that are usually considered “comfortable” as they are to hot environments. For example, rectal temperature equal to or greater than 40 degrees C or 104 degrees F are not uncommon, even in athletes who compete at environmental temperatures as low as 5 degrees to 16 degrees C, 41-61 degrees F.

Prevention of Heat Disorders

The occurrence of heat disorders can be greatly reduced by: 1. Adequate electrolyte (salt) and water replacement, 2. Acclimatization to heat, and 3. Awareness of the limitations imposed by the combination of exercise, clothing and environmental heat.

Salt and Water Replacement

Water and salt replacement during and following work in the heat is absolutely essential. It is not unusual for an athlete to lose 5 to 15 pounds (mostly water loss I.e. sweat) during each practice or during a game. Awareness needs to be taken by the coaches and the athlete as to how much weight they are losing.  It is not a bad idea to weigh athletes before practice, mid practice and at the end of practice during really hot days to determine the water loss.

Water Replacement

The availability of water should be unrestricted at all times during scheduled practices and games. The super-hydrated athlete suffers no impairment of efficiency.  However, large amounts of water should not be consumed all at once because the athlete may feel bloated under these circumstances. The best procedure is to schedule frequent water breaks as well as to encourage the drinking of water.

For athletic teams, water consumption can be facilitated by maintaining several water stations strategically located around the practice field. This allows the player convenient access to water. Frequent trips to the water tanks and drinking small amounts  are ideal. This procedure is physiologically more sensible than having a break every hour or so, during which the athletic might gulp  large amounts. Also, it allows for some efficient use of practice time. Ice water buckets, pressurized garden-spray containers, and thermos jugs are containers that can be properly located and adequately maintained. 

What the Athlete Should Drink

Many liquids may consumed to replace lost water and satisfy thirst,  but  what is needed most is drink that will provide for hydration without “lying in the stomach” for too long. A cold drink that is hypo tonic and has a concentration of sugar below that which retards gastic emptying is ideal.  The best drink should contain less than 2.5% sugar. Having made these observations, we must emphasize that, under most circumstances, water  is the best and most available drink. If modest dehydration occurs during a practice, fluids can be consumed over the next 24 hours to re-hydrate the athlete. 

Guidelines for fluid intake for athlete

Content of drink

The drink should be:

hypo tonic (fe solid particles per unit of water) low in sugar content (less than 2.5 grams per 100 ml of water)

Low in sugar content (less than 2.5 grams per 100 ml of water.

Cold (roughly 45-55 degree F, or 8-13 degree C

Palatable (it will be consumed in volumes ranging from 100 to 400 ml, or 3 to 10 ounces

Amount to  be ingested before competition 

Drink 400-600 ml ( 13.5 -20 ounces) of the above drink about 1 hour before the start of competition.

Amount to be ingested during competition

Drink 100-200 ml (3-6.5 ounces every 10-15 minutes)

Postcompetition diet

Following competition, modest salting of foods and the ingestion of drinks with essential minerals can adequately replace the electrolytes (sodium and potassium) lost in sweat.

Detection of dehydration

The athlete should keep a record of his or her early morning body weight (taken immediately after rising, after urinating and before breakfast) to detect symptoms of a condition of chronic dehydration.

Value of drinks

Drinks are of significant value in races or sporting events lasting 50-60 minutes.

Drinks are of significant value during long practice sessions under warm conditions in both individual and team sport settings. 

Lactic Acid Buffering: Part Deux

So far we have learned that the difference in lactate production and its removal from the blood results in reduced levels (that is, return toward resting values) during recovery from exercise, and that its removal is faster during controlled exercise-recovery than during rest-recovery. Our next task is to learn what happens to the lactic acid and why its removal is faster during exercise-recovery.

There are four possible fates of lactic acid.

1. Excretion in Urine and Sweat. Lactic acid is known to be excreted in urine and sweat. However, the amount of lactic acid removed in this manner during recovery from exercise is negligible.

2. Conversion to Glucose and/or Glycogen. Because lactic acid is a product of carbohydrate metabolism (glucose and glycogen)during anaerobic work, it can be reconverted to either of these compounds in the liver (glycogen and glucose) and in muscle (glycogen) given the required ATP energy. However, as previously mentioned, glycogen resynthesis in muscle and liver is extremely slow compared with lactic acid removal. In addition, the magnitude of the changes in the blood glucose levels during recovery are also minimal. Therefore, conversion of lactic acid to glucose and glycogen accounts for only a small portion of the total lactic acid removal.

3. Conversion to Protein, Carbohydrates, including lactic acid, can be chemically converted into protein within the body. However, once again only a relatively small amount of lactic acid has been shown to be converted to protein during the immediate recovery period following exercise. 

4. Oxidation / Conversion to Co2 and H2o. Lactic acid can be used as a metabolic fuel, mostly by skeletal muscle, but heart muscle, brain, liver and kidney tissues are also capable of this function. IN the presence of oxygen, lactic acid is first converted to pyretic acid and then to Co2 and H2o in the Krebs Cycle and the electron transport system, respectively. Of course , ATP is resynthesized in coupled reactions in the electron transport system.

The use of lactic acid as a metabolic fuel for the aerobic system accounts for the majority of the lactic acid removed during recovery from exercise. Although this holds true for both rest- and exercise-recoveries oxidation accounts for more lactic acid removal in the latter than in the former. AS just mentioned, several organs are known to be capable of oxidizing lactic acid. However, it is fairly well agreed that skeletal muscle is the major organ involved in this process.  In fact, most of all lactic acid oxidized by muscle is thought to occur within slow-twitch rather than fast twitch fibers. These are major reasons why lactic acid removal is faster during exercise-recovery than during rest-recovery. For example, the former, both the blood flow carrying lactic acid to the muscles and the metabolic rate of the active muscles are greatly increased. In addition, the type of exercise selected during most exercise-recoveries prudentially recruits slow-twitch fibers to perform the work.

Buffering Lactic Acid: Recovering From Exercise

When we exercise at high intensities we often feel a burning in the muscle. This burning sensation is lactic acid building up in the muscle tissue.  When all the oxygen is depleted from the cell hydrogen atoms increase forming lactic acid. Once lactic acid accumulates enough in the cell, muscle contractions cease.  After training people associate their sore muscles to lactic acid still being in the muscle tissue.  The pain is due to DOMS (delayed onset muscle soreness), which I will discuss later. For this discussion I will be talking about lactic acid and its effect on the cells of the body as a result of intense exercise.

When lactic acid, the product of glycolysis (the anaerobic phase of carbohydrate metabolism), accumulates to high levels in blood and muscle, fatigue sets in. Therefore, full recovery from exercises in which maximal amounts of lactic acid have accumulated  involves  the reduction of lactic acid levels from both the blood and skeletal muscles that were active during the preceding exercise period.

Several important questions related to this process that need answering are 1. How long does it take to remove the accumulated lactic acid, 2. What factors influence the speed of lactic acid reduction, 3. What happens to the lactic acid, and 4. What is the relationship between the removal of lactic acid during recovery and the slow-recovery phase?

Speed of Lactic Acid Removal
The time course of the removal of lactic acid from blood and muscle is 5-60 minutes, respectively. During sub maximal, but heavy, exercise, in which the accumulation of lactic acid is not as great, less time is required for its removal during recovery.

Effects of Exercise during Recovery on Speed of Lactic Acid Removal

When a person rests throughout the duration of the recovery period this is known as rest-recovery.
However, lactic acid can be removed from blood and muscle more rapidly following heavy to maximal exercise by performing light exercise rather than by resting throughout the recovery period. Such a recovery is referred to as exercise-recovery, or active recovery, and is similar to the warm-down procedures that most athletes have practiced for many years. A study  (Belcastro, Bonen) was done years ago that determine the effects of the exercise recovery on lactic acid removal. They had subjects run 1 mile on 3 separate days. Three different recovery periods were used 1. Rest, 2. Continous exercise consisting of jogging at a self-selected pace and, 3. Intermittent exercise of the kind normally practiced by athletes.  Both exercise-recoveries resulted in substantial increases in the rate of lactic acid removed from the blood. The removal rate was fastest during the continuous jogging recovery. This information suggests that athletes should exercise continuously throughout the recovery period rather than intermittently, which is their normal practice.  Lactic acid, rather than being removed should be thought as a fuel source for muscle and as a source for the partial regeneration of liver and muscle glycogen.

How much exercise should be performed during recovery to promote optimal lactic acid removal? The answer to this question is for untrained subjects, the recovery exercise that produces the fastest or optimal rate of removal of blood lactic acid is one in which the oxygen consumption (VO2) is between 30 and 45% V02 max, or 1.0 to 1.5 liters per minute, or 15 to 20 milliliters per kilogram of body weight per minute. With trained subjects performing recovery exercise consisting of running or walking, it has been shown that lactic acid removal is optimal at intensities between 50 and 65% V02 max (Belcastro, Bonen). The major reason for this difference is probably related to the state of training of the subjects than to the difference in exercise modes (running walking versus bicycling).  In other words, the higher the fitness level (with greater mitochondria density, blood perfusion, and enzyme capacities), the higher the recovery exercise intensity for optimal lactic acid removal.

One more point. When the intensity of the recovery exercise is either below or above the optimal limits, lactic acid is removed more slowly. In fact, when the intensity of the recovery exercise  is greater than 60% VO2 max the removal rate of lactic acid is actually less than that during rest-recovery. The reason for this is that during the recovery exercise itself, more lactic acid is being produced than is being removed.

Elite middle-distance athletes often appears to follow the procedure of maintaining an active recovery near the 70% VO2 Max for the first few minutes, then dropping to 40% VO2 max for the later recovery period.

tags: lactic acid, bodybuilding, Daryl Conant, Ron Kosloff, Vince Gironda

Staying Balanced

We often hear fitness instructors and trainers talking about performing balance exercises.  Balance exercises are apart of the functional training spectrum that seems to be the new craze in gyms across America. To understand balance you must learn the fundamental structure of the proprioceptors of the muscle.  I would now like to discuss in detail the structures responsible for helping the body  to be more aware in three dimensional space.


Muscle Sense Organs

There are several types of sense organs in muscle. The pain resulting from exercising too vigorously after long disuse (muscle soreness) or from torn muscle fibers are good examples of muscle sense organs at work. These pain receptors, which are few in number, are found not only in the muscle fibers themselves but also in blood vessels (arteries, but not veins) that supply the muscle cells and in the connective tissues that surround the fibers.

Proprioceptors

Other kinds of sense organs found within the muscles and joints are called proprioceptors. The function of proprioceptors is to conduct sensory reports to the CNS (central nervous system) from (1) muscles, (2) tendons, (3) ligaments, and (4) joints.  These sense organs are concerned with kinesthesia or kinesthetic sense, that in general, unconsciously tells us where our body parts are in relation to our environment.  Their contributions enable us to execute a smooth and coordinated movement, no matter whether we are putting a golf ball, hitting a home run, or simply climbing an unfamiliar flight of stairs without stumbling. They also help us to maintain a normal body posture and muscle tonus. The tendency for the lower jaw to drop, the head to droop forward, and the knees to buckle because of the effects of gravity are all counterbalanced by the so-called antigravity muscles, which relay information regarding position in space.

How do these sense organs or proprioceptors function? We can begin to answer this question by first describing how each type of sense organ sends specific sensory information to the CNS. There are three important muscle sense organs concerned with kinesthesia: muscle spindles, Golgi tendon organs, and joint receptors.

The Muscle Spindle

Muscle spindles are perhaps the most abundant type of proprioceptor found in muscle. Briefly, muscle spindles (also called stretch receptors) send information to the CNS concerning the degree of stretch of the muscle in which they are embedded.  This provides the muscles with information, for example, as the exact number of motor units necessary to contract in order to overcome a given resistance ; the greater the stretch, the greater the load and the greater the number of motor units required.  The spindles are important in the control of posture and, with the help of the gamma system in voluntary movements.

Structure of the Spindle

It is nothing more than several modified muscle fibers contained in a capsule, with a sensory nerve spiraled around its center. These modified muscle cells are called intramural fibers to distinguish them from the regular or extramural fibers. The center portion of the spindle is not capable of contracting, but the tow ends contain contractile fibers. The thin motor nerves innervating the ends are of the gamma type and are thus called gamma motor nerves or fusimotor nerves. When they are stimulated, the ends of the spindle contract and pull against the center region. The larger motor nerves innervating the regular or extramural fibers are called alpha motor nerves. When they are stimulated the muscle contracts in the usual sense.

Function of the Spindle

As mentioned before, the spindle is sensitive to length or stretch.  Therefore, because the spindle fibers are found throughout the muscle and lie parallel to the regular fibers, when the whole muscle is stretched, the center portion of the spindle is stretched also. This stretching activates the sensory nerve (annul spiral nerve) located there, which then sends impulses to the CNS.  In turn, these impulses can  activate the alpha motor neurons that innervate the regular muscle fibers, and the muscle contracts. If the muscle shortens when it contracts, the spindle also shortens, thus stopping its flow of sensory impulses; the muscle then relaxes.

The spindle is sensitive to both the rate of change in length and to the final length attained by the muscle fibers. The functional significance of these two types of sensitivity can be illustrated by a muscle engaged in a steady contraction, as when the elbow is flexed steadily against a load (for example, when holding a book). The type of stretch placed on the muscle because of the load is called tonic stretch and is concerned with the final length of the muscle fibers. If the load is light, the fibers will be stretched only moderately, and the frequency discharge of the sensory impulses from the spindle will be low. Thus, only a few motor units are called on in keeping the load steady.

If there is and unexpected increase in the load being held, such as by adding another book, the muscle will be stretched again. This is evidenced by the fact that the forearm will be lowered owing to the added load. The ensuing reflex contraction initiated by the spindle will reposition the forearm to its original level. However, there will be some overcompensation; that is, at first the contraction will be greater than needed. The greater and more abrupt the increase in load, the greater the frequency of discharge of the spindle, the greater the contraction, and the greater the overcompensation. In other words, with this type of stretch, called phasic stretch, the spindle is responding to the rate or velocity of the change in length and not to the length per se.

The Gamma System

There is one other way in which the spindle can be stretched. Contractile ends of the spindle fibers are supplied with motor nerves from gamma neurons.  These gamma neurons can be stimulated directly by the motor centers located in the cerebral cortex of the brain via their pyramidal tract nerve connections to the spinal cord.  When stimulated in this manner, the ends of the spindle contract, thus stretching the center portion and stimulating the sensory nerve. In other words, the muscle spindle can be activated by itself, apart from the rest of the muscle.  This special neural arrangement is called the gamma system or gamma loop. This kind of setup provides a very sensitive system for the execution of smooth, voluntary movements. Furthermore, it has been suggested that the gamma neurons have a recruitment order much the same as the motor neurons of alpha motor neurons. Although all the functional interrelationships in producing precise voluntary movements are not completely understood, this combined recruitment is called alpha gamma coactivation. When thinking about voluntary movements and alpha-gamma coactivation, considers that gamma firing occurs just a bit prior to alpha activation. This puts an initial stretch bias on the sensory system resulting in some firing from the annul spiral nerve. One way to stop this backflow of sensory impulses is to contract (shorten) the whole muscle to precisely the proper amount, making a perfect matchup of ìgamma-alphaî activation (note reversal of terms to emphasize order of firing) and a turnoff of backflow. If the matchup is imperfect, the initial bias would not be completely removed.  In this event, the continued backflow of afferent impulses would signal the alpha motor neurons to send additional impulse volleys. The muscle would undergo further contraction with a concomitant decrease in sensory backflow. This process would be continued until all the initial bias is removed. Remember that these processes occur very rapidly but, at the same time, do require time.

For an example of how the gamma system works, let us go back to the person voluntarily holding a book in a fixed position, elbow flexed at 90 degrees. I  stated that the tonic stretch on the entire muscle created the load provides information that keeps the load (book) in a relatively fixed position. However in addition, the gamma neurons are stimulated by impulses sent down directly from the motor cortex.  The ends of the spindle contract, the sensory nerve sends impulses back to the CNS and additional information is provided concerning the number of motor units that is required to maintain the original voluntarily initiated position. This additional information provides the refinement that is needed for a smooth rather than jerky movement.

In conclusion, there are three ways that the muscle spindle can activate the alpha motor neurons that cause the muscle to contract: (1) by tonic stretch,, (2) by phasic stretch, (3) by the gamma system or gamma loop. All these controls work together to provide for effective, coordinated, and smooth movement.

Muscle Soreness and Types of Contraction Part II

There are two types of muscular soreness-- acute and delayed. Acute soreness is due to muscle ischemia (lack of adequate blood flow). Delayed soreness (onset 24 to 48 hours after exercise) could be due to torn muscle tissue or muscle spasms but is more likely due to disruption of the connective tissues, including the tendons. There is no known prevention or cure for soreness, however, stretching exercises may relieve it when present and may sometimes prevent or delay its onset. Delayed muscular soreness is greatest following eccentric contractions and is least following isokinetic contractions.

With isotonic strength programs, there is no single combination of sets (number or repetitions performed consecutively) and repetition maximums (maximal load that can be lifted a given number of repetitions before fatiguing) that yields optimal strength gains. However, most programs should include between one and three sets with repetition maximums between three and nine. Although improvement in strength and muscular endurance can be greater with low repetitions and low resistances, respectively, equal increases in strength and endurance have been found with either program.

Isometric programs can significantly increase strength by training 5 days per week, with each training session consisting of 5 to 10 maximal contractions held for 5 seconds each. Isometric endurance can also be improved, but the design of such a program varies considerably.

Eccentric exercise programs, in comparison with isotonic and isometric programs, are not any more effective in developing strength and endurance. They may excel, hover, in developing eccentric contraction strength.

Isokinetic programs are speed specific (i.e. they cause maximal gains in strength and endurance at velocities of movement equal to or slower, but usually no faster, than the training velocity). Gains in isokinetic strength and endurance can be made with programs consisting of as little exercise as 1 minute per day, 4 days per week, for 7 weeks (total time= 28 minutes). In theory and in comparison with other programs, isokinetic programs should lead to the greatest improvement in muscular performance. Once gained, strength and endurance are retained fro relatively long periods of time.

Circuit training consists of a number of stations where a given weight-lifting exercise is performed within a specified time. It, too, is an effective training technique for improving muscular strength, muscular endurance and to a lesser extent, flexibility and cardiovascular endurance.

Although a few studies suggest little or no improvement in speed of contraction, most show that weight-training programs do increase both speed and power of contraction. Specific sports skills can be significantly improved through weight-training programs.  Flexibility, the range of motion about a joint, is related to health, and, to some extent, to athletic performance.  Regularly scheduled programs involving stretching exercises (2 to 5 days per week, 15 to 30 minutes a day) will improve flexibility within a few weeks.

Muscular strength: isotonic, isometric, isokinetic

Muscular strength is the force that  a muscle or muscle group can exert against a resistance in one maximal effort. There are four types of muscular contraction: isotonic, isometric, eccentric and isokinetic.

With isotonic contractions (muscle shortening while lifting a constant load), the tension developed the range of motion is related to (1) the length of the muscle fibers, (2) the angle of pull of the muscle on the bony skeleton, and (3) the speed of shortening. As a result, the tension developed during the lifting of a constant load varies over the full range of joint motion with the muscle stressed maximally only at its weakest point in the range.  This contrast to an isokinetic contraction in which the tension developed by the muscle as sit shortens at constant speed is maximal at all joint angles.

An isometric contraction is one in which tension is developed but there is no change in the external length of the muscle. An eccentric contraction refers to the lengthening of a muscle during contraction.

Local muscular endurance is usually defined as the ability of a muscle group to perform repeated contractions (either isotonic, isokinetic, or eccentric) against a load or to sustain a contraction (isometric) for an extended period of time. However, muscular endruance may also be defined as the opposite of muscular fatigue.

Physiological changes that accompany increased strength are as follow:

1. Hypertrophy-- an increase in the size of the muscle due to an increased size muscle fibers (mainly fast twitch) and myofibrals, an increased total amount of protein, and increased number of capillaries, and increased amounts of connective tendinous, and ligamentous tissues.

2. Biochemical changes-- including increased concentrations of creatine, PC, ATP and glycogen and decreased volume of mitochondria, but only small changes in anaerobic and aerobic enzyme activities.

3. Adaptations within the nervous system including changes in recruitment pattern and synchronization of motor units.

The physiological principle on which strength and endurance development depends is called the overload principle. It states that strength and endurance increase only when a muscle performs at its maximal capacity. With weight training programs, the resistance against which the muscle works should be increased periodically as gains in strength are made.  This is the principle of progressive-resistance exercises or PRE.

Weight training is specific in that gains in strength and muscular endurance improve skill performance to the greatest extent when the training program consists of exercise that include the muscle groups and simulate the movement patterns used during the skill. Also, the strength training is specific to the joint angle at which the muscle is trained (isometrics) and to the type of contraction used.

Technically Difficulties

Hi folks,

I have been experiencing technically difficulties with my computer and have not been able to post any new blogs. I am working hard to fix the problem.  I plan on being back up and running soon. Sorry about this.

Daryl

Thank You

I would like to thank all the people that came to the book signing and seminar at Border's Bookstore in Portland Maine.  I plan on having more seminars in the near future.  I will make updates on the blog to when and where these events will take place.  The sale of diet EARTH is going well it has been sold all over the world. My message of real nutrition and how food works in the body is getting out.  Thank you all who have purchased it.

tags: daryl conant, diet EARTH, Ron Kosloff, Vince Gironda