Is it worth doing doubles on 35-40 miles a week?

don't speak unless spoken to wrote:

don't forget about this... wrote:

Virtually everyone here is in the huge chasm between the professionals and the novices, and most of us would benefit doing from a long run in training. The benefits are well known and have been studied for decades.

Link:www.themotherrunners.com/benefits-of-l...

Long runs:

Build the number of mitochondria in your cells. These are the “energy factories” that power movement and cell respiration.

Increase max VO2 and blood volume, maximum stroke volume (the amount of blood ejected from the heart with each beat), and build new capillaries and red blood cells. This helps get oxygen (to use for energy) to your muscles.

Build mental toughness. When you toe the start line, you know you can go the distance because you already have—and in some cases—and then some.

Make your running more efficient. Muscles learn through practice, so your stride will improve through consistent long runs.

Teach your body how to fuel itself. Your body will learn to tap into fat before glycogen, delaying glycogen depletion during a long race. This helps delay hitting that proverbial wall.

Make your muscles, bones, and tendons stronger. Running for prolonged periods increases the strength of the leg muscles and connective tissues.

Increase your body’s ability to use fat as fuel. Your body uses both carbs (glycogen) and fat to fuel your runs. Long runs increase your body’s ability to optimally and efficiently use these fuel sources to power you.

Make you faster! By improving your endurance, you’ll be able to hold a certain pace for a longer period of time. And, then as your slow-twitch muscles get tired, your fast-twitch muscle fibers pitch in.

Embarrassing. Telling malmo about mitochondrial growth and linking to some hobby jogger website LOL. Easy runs already do all the things mentioned in that article. Novices need to run. Period. As often as they can. That is the opposite of what some people do - they put 40% of their mpw into the long run, get tired, then take days off or something. Not what you want to do.