Trainings affect on the body?

Question

How does training affect the cardiovascular system, the lungs and the muscles?

Answer 1

There is a difference between resistance training and endurance traing, but most research is done in endurance training, so I'll assume you mean this.

The heart gets larger, increasing the stroke volume, and therefore decreasing heartrate becasuse the metabolic need of the rest of the body is still about the same. Cappillary beds become more dense, allowing greater perfusion of muscles.

I would guess that the lungs adaptivly expand, but this wouldn't be too much if at all.

Muscle fibers will adapt to the exercise stimulus, IE: weight training would give more fast twitch fibers (aka: white or glycolitic fibers) and endurance training would give more slow twitch fibers (aka: red fibers) The muscle cells (myocytes) will produce more mitochondria per cell as well. Protiens in muscle cells that are responsible for ATP production in the Citric Acid cycle will increase. It is the gold standard to measure the Citric acid synthase protein to see if exercise training has had an effect. I hope this gets you where you need to go friend.

Answer 2

It is a common misconception that the heart gets larger, it doesn't. The stroke voulme increases however and so does cardiac output so a larger amount of blood is pumped outta the heart in every beat.