Никак не могу разобраться с этими мышцами. Книга о фитнессе. Постоянно в разных контекстах употребляется lean muscles

например:
The best way to burn fat is through resistance excercise, becase that creates lean muscle - and lean muscle is the most efficient burner of fat.

или

on a low-calory diet, 45% of weight loss can come from muscle. Lean muscle burns fat. If you reduce lean muscle, your metabolic rate goes down and you burn fat more slowly

Заранее спасибо

http://www.sixpacknow.com/12weekleanmuscleplan.html ниже цитата из этого сайта:

If you're in search of creating a leaner, more sculpted physique,

then this is the perfect Program for you.

The 12 Week Lean Muscle Plan is not designed for building

huge bodybuilder sized muscles, it has been developed

to appeal more for men and women to gain leaner muscle size

whilst keeping body fat levels to a minimum.

http://www.treeoffitness.com/Articles/Article--Long_Lean_Muscles--Wishful_thinking_or_factual_distinction.htm,цитата:

You can't "create" a long muscle

For starters, to say a given workout will deliver “long, lean muscles” suggests that the undesired opposite is a workout that causes short, bulky muscles. From an exercise physiology perspective, this makes no sense, as our bodies are naturally made up of both long and short muscles. These varying lengths are pre-determined anatomically; they cannot be altered through a select type of exercise. Your rear deltoids (back shoulder muscles) are short, yet no one, I can assure you, has ever looked bulky because of an over-developed rear deltoid! On the other hand, the longest muscle in the body is the sartorius (hip/thigh). Not only is this long and relatively slender in shape, it is likely to remain so….even if you train it with a high amount of resistance.
В общем, сходи на гугл.Есть что посмотреть

Попробуй сформулировать окнчательный вариант по-русски сама.Мое предположение, что в отличие рельефных мышц(bulky muscles)как у культуристов,lean muscles - это более продолговатые,вытянутые,короче,более эстетично выглядящие.Вот.