Basically the time under stress brings in red muscle or the slow twitch fibers into action.
If the movement is controlled and the set goes longer the red fibers are used.. If the movement is explosive and heavy then the white fibers are used.
For example squatting for 15 rep range incorporates red fibers of the thighs very well
The type one muscle fibers are characterized as being the slow twitch oxidative muscle fibers. They contract slowly, they have the highest tolerance to fatigue as compared to the other types of muscle fibers, and there main fuel source tends to be triglycerides. This being said the best way to train this type of muscle fiber would be with low intensity endurance type exercises, such as jogging a long distance, or walking, or performing 50 push ups vs. 8 reps on the bench press.
Type I (red) muscle fibers, which have slow oxidative characteristics, are those primarily called on for long-distance running. These are more commonly referred to as 'slow-twitch' muscle fibers.
Red muscle fibers, also known as slow-twitch or Type I fibers, are characterized by their endurance and ability to sustain prolonged activity. They are best utilized in athletic endeavors that require stamina, such as long-distance running, cycling, and cross-country skiing. These fibers rely on aerobic metabolism, making them ideal for activities that demand sustained energy over extended periods.
The types of intrafusal fibers that respond best to a sustained stretch are the static nuclear bag fibers and the chain fibers. These fibers are sensitive to changes in muscle length and are involved in proprioception. They help maintain muscle tone and provide feedback to the central nervous system about the degree of stretch in the muscle. Dynamic nuclear bag fibers primarily respond to rapid changes in muscle length rather than sustained stretch.
Squat.
Do burpees
The muscle fibers best suited for running a marathon are slow-twitch muscle fibers, also known as Type I fibers. These fibers are highly resistant to fatigue and are efficient at using oxygen to generate energy for prolonged, endurance activities. They have a rich supply of blood vessels and mitochondria, enabling sustained aerobic metabolism, which is essential for long-distance running. In contrast, fast-twitch fibers (Type II) are more suited for short bursts of strength and speed.
Lunges. see: http://en.wikipedia.org/wiki/Lunge_(exercise)
The only way to build muscle is with exercise. That being the case, since exercise requires calories, building muscle will also burn off fat.
Appropriate muscle refers to the specific muscle groups or types of muscle fibers that are best suited for a particular activity or exercise. For instance, athletes may target fast-twitch muscles for explosive movements like sprinting, while endurance athletes focus on slow-twitch muscles for long-distance activities. Understanding the appropriate muscle types can help optimize training and improve performance in various sports or fitness disciplines.
The best muscle enhancers for women would be to eat a lot everyday as well as exercise at a routine you can pick out, suggestively 1 hour a day, for you.
Best ask a Doctor - probably just muscle fatigue from too much exercise