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Tuesday, March 8, 2011

Pranayam and cardio-pulmonary fitness

The heart supplies blood to all the organs in the body, it pumps out blood via blood vessels, once the blood reaches these places it empties its package of nutrients and the needs to get back for a refill of nutrients! there are veins that carry blood back to th heart.
The blood in the feet, calves and thighs is far away from the heart how does it get back?
This is where a simple arrangement of valves and respiratory or breathing movements comes to work and pushes or 'sucks' the blood back to the heart(venous return).
The calf muscle and the thigh muscles play the important roles of a pump squeezing the blood upwards as they contract, and there are, located in the veins of the calves and the thighs a number of valves that allow blood to flow only up, towards the heart, for example 1 valve is in the calf next one higher up next still higher up in the thigh, the valve, opening only when the blood is flowing up to the heart and then closing when the blood 'falls' back when the muscles are momentarily relaxing! Thus the blood flows only up.
In this way the blood reaches the abdominal cavity.
When we exhale the lungs constrict, creating a vacuum or negative pressure below in the abdominal cavity, this vacuum in the abdominal cavity sucks up the blood from the thighs and the blood travels upwards. The blood does not flow back into the lower extremities as the valves mentioned earlier close upon the back flow of blood.
After exhalation we inhale this expands the lungs which in turn increase in size and push down upon the abdominal cavity squeezing it, the pressure within the abdominal cavity rises the blood rushes up to the thoracic cavity (region of lesser pressure) and, finally into the heart!
This principle of pressure changes during respiratory movements is used in the exercise of PRANAYAMA.
This activity deals with breathing exercises which aid venous return thus improving cardio-pulmonary fitness, reducing cardiac workload so improving the efficiency of the heart as a pump. If done correctly it will help reducing risk of cardiac ailments and will improve cardiovascular fitness.



Intellectual Property of Dr. Mihir P. Patki please use with permission

Sunday, August 8, 2010

What is Vo2 Max or maximal oxygen consumption, maximal oxygen uptake, aerobic capacity?

Vo2Max determines the cardiovacular fitness of an individual. it is the volume of oxygen used by the muscles for contraction in a unit of time.
The muscles need energy for contraction, with the help of oxygen and few other elements energy(ATP) is created. This energy feuls muscle contraction. in short, the better the supply of oxygen to the muscle longer will the activity last.
Oxygen reaches the body via the Lungs, the lungs pass it on to the blood and the heart pumps it all around the body.
Oxygen is supplied to the muscle by blood vessels, the muscles extract the oxygen from the blood vessels and use it to create energy needed for muscular movement.

This phenomenon of providing and extracting oxygen to the muscle is the Vo2max = V - volume per time, O2 - oxygen, max - maximum.

It is essential for any athlete to have a high Vo2Max, whatever the sport. The Vo2Max is a indirect indicator of the individuals overall health. It is a standard for measuring physical fitness.
In endurance sports the greater the Vo2Max the longer and faster the sportsperson will perform.
In strength sports if the individual has a high Vo2Max then the formation of harmful chemicals or metabolites(lactic acid) is minimal and the sportsperson can maintain a set for longer duration for max strength gains.

Monday, July 12, 2010

High Protein diets and calcium

Precautions while on a high protein diet.
  • Protein, water and calcium: When on a high protein diet, take care of the water input as high protein diet is known to cause increase concentration of calcium in urine. 
  • Habitual excess protein intake is a significant risk factor for calcium loss via the kidneys. Calcium excretion also accompanied with daily urinary excretion of urea. The calcium excretion with animal protein intake was found to be significantly positive in both sexes and in each age group whereas that with plant protein was not. Findings suggest that regular use of excess protein in diets may augment calcium excretion in the urine, at least in the elderly.
  • Sports persons especially bodybuilders control their water input when they are near the competition date, and they increase their protein intake at the same time, this may lead to excess excretion of calcium.
  • Plenty of water, regular physical activity (30 minutes walking, more than 5 days a week) and monitoring kidney profile should prevent any adverse effects.

Thursday, March 22, 2007

BIO MECHANISM OF A SLIPPED DISK


The vertebral column is made up of thick cubical bones which are mounted on top of one another to form a tall structure eg., bricks mounted on top of each other.


the vertebral coloumn bones stacked up one on top of the other!


In between these bricks lies the soft cushion known as the inter vertebral disc.
A soft rubber like cushion is situated between the bricks or bones

An intervertebral disc is made up of a rubber like material, it has a central pulp(nucleus pulposus) surrounded by circular fibrous tissue called annulus fibrosus. shown below fig 1 fig 2 and fig 3

fig 1 fig 2

The function of the disc is to act as a shock absorber and joint between the two vertebral bones , as the person jumps, runs walks or lifts weight the disks absorb the shocks, also when we twist the waist. the disks acting as the joint around which the bones pivot.
The disk prevents the vertebral bodies from coming in contact with each other.

On top of the vertebral column lies the persons head and below, the vertebral column rests on the sacrum. The weight of the head causes the vertebral column to be compressed between the head and the sacrum. as we walk or run the forces generated travel up via the ankle joint, knee joint, hip joint and reach the sacrum bone, from here the forces collide against the vertebral coloumn(lumbar vertebrae)

fig 3

These forces can cause damage to the body and they need to be dampened.
To prevent compression and friction between the vertebrae the 'shock absorber disk' comes into action.
As the person jumps vertebrae, one on top of the other are pressed against each other, the pressure within the central pulp rises and the pulp tries to push out against the annulus fibrosus fig 4, The annulus counters this by tensing around the pulp! This mechanism contains the pulposus within the annulus! and prevents the pulposus from extruding out of the annulus and the vertebrae from coming in contact with each other.


fig4 fig 5 fig 6
If (1) the pressure built up within the annulus is too great or (2) if the annulus has hardened due to degeneration or simply dried up(dessicated) or (3) if the vertebral column is twisted in an abnormal fashion or pulled violently by the ligaments and muscles attached to it, then the annulus bulges out fig 6 or it gives way and the pulp finds its way outside called extrusion fig 7,8,9, resulting in failure of the shock absorber mechanism and giving rise to the phenomenon known as the slipped disk.

When the pulposus bulges into the spinal canal or the pulp breaks out of the annulus and enters the vertebral canal to come in contact and compress the spinal cord it is known as herniation/ prolapse of an inter vertebral disc.




extrusion of the pulposus fig 7,,8,9.