Growing up I always watched the cartoon GI JOE. They always ended it with Sergeant Slaughter giving the advice "Knowing is half the battle." Training is the same. Knowing what you want, why and how to achieve it.
I'm going to outline a two methods to increase blood volume.
Eccentric Cardiac Hypertrophy:
The goal is to improve the ability of your heart to deliver oxygen and develop more blood vessels peripherally. The work your doing stimulates eccentric cardiac hypertrophy. You get a bigger left ventricle. This gives you the ability to pump out more blood per heart beat.
The bigger heart allows you to pump out more blood with less heart beats, so less work. This allows more oxygen to your muscles. More oxygen equals better aerobic capabilities.
This is best developed by staying in a heart rate about 130-150bpm. The session has to last at least 30 min with 60-90 being the optimal period. If you currently have a resting heart rate in the 60-70s, this would be a good type of training to engage in. If your returning to training after a long lay off, again this would be a great place to start.
Now, if you go over the 150bpm, you are doing to much intensity. What happens physiologically is that you don't give your heart enough time to fill up with enough blood to cause a stretching thus causing the eccentric hypertrophy to occur.
Concentric Cardiac Hypertrophy:
So now if you start going over 150bpm what happens? Well it depends! If you apply the correct stress/reps/rest you get thicker walls of the heart.
The goal again is to increase how much blood can be pumped. Instead of getting a bigger left ventricle where it can push out more volume, you get a thicker heart with stronger contractions which can push out more volume. There seems to also be an increase in the number of mitochondria in the heart as well.
These adaptations come into importance when the intensity of your activity increases. This improves the power endurance of your heart.
This adaptation is best developed by going all out (heart rate as high as possible) for 60-120 seconds and then resting for up to 5 min with keeping your heart rate around 120-130. If it takes shorter or longer you start the next rep when your heart rate reaches the targeted number.
This is again information I've been reading about through Joel Jamiesons Ultimate MMA Conditioning and some other materials. The big takeaway is that you should know the goals of your training. Know the adaptations your trying to achieve. Know how to achieve those adaptations. Good luck.