How muscles work, use fuel and get built

Muscles are such a machine in our body, composed of thousands of microfibers, they act upon chemical and nervous responses to produce movement and force by the action of contraction and relaxation.

There are three types of this specific tissue: skeletal, cardiac and smooth, depending if the contraction occurs conciously or not. Smooth and cardiac tissue can move without our concious thought, and it is wonderful they do so!

Smooth or "involuntary muscle" is found within the walls of organs and structures such as the esophagus, stomach, intestines and blood vessels. Cardiac tissue is also "involuntary" and obviously is found in the heart.

Skeletal or "voluntary movement tissue" is attached with flexible structures called tendons to the bones.

And speaking about concious movement, there are two types of voluntary fibers: slow twitch and fast twitch.

Slow twitch fibers can contract for long periods of time needing very little force.

Fast twitch fibers contract fast but they fatigue rapidly.

The fuels

Carbohydrates and fat give this movement tissues their fuel (called ATP, Adenosyn Tri Phosphate) by oxidative reactions (meaning they need oxygen to happen) and some anaerobic reactions too (meaning they don't need oxygen).

To know more about how glucose is affected by activity click here

In order to build and maintain the movement tissue and other lean tissue protein is also used sometimes, but body handles it differently during activity than during rest.

Protein for building muscle tissue and for fuel

Beneficial effects of Musculoskeletal Fitness (MSF)

The beneficial effects of cardiorespiratory fitness are well known, but less studied are the effects of muscles strenght and endurance. We all know that being inactive, produces atrophy and weakening of our movement tissue. But what are the implications of a low MSF?

Morrow and other authors published in the Medicine and Science in Sports and Exercise Journal, a study with more than 9000 subjects where the following exercises were applied to them, and mortality rates were calculated for low, moderate and high MSF:

* 1 Minute sit up test.

* 1 Repetition maximal leg press.

* 1 Repetition maximal bench press.

Conclusions were that mortality rates are higher in persons that have lower musculoskeletal fitness. This means that by keeping our tissue in good condition we can reduce our risk for factors that increase mortality and not only avoid the atrophy or weakening of the tissue.

For an extra tip, a meta analysis reported in the Journal of the American College of Sports Medicine the effect of caffeine ingestion on muscular strength and endurance, and it results that caffeine improves maximal voluntary contraction (but exclusively in the knee extensors). Think about it if you need some help with your knees!

Is it true that massage helps after strenuous exercise?

The American College of Sports Medicine published in 2009 an article from Wiltshire and colaborators. They tested the hypothesis that massage aids muscle recovery by increasing the blood flow to improve the lactic acid removal, discovering that massage does not aid, but instead it impairs the ions removal.

Though massage doesn't seem to be a good recommendation after strenous exercise, what do you think about a good shower?

If you want to learn more about exercise, click here!

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