השוואת שיטות

	מיון סיבי MHC	קצב פיתוח כוח
תחום	מדעי הספורט	מדעי הספורט
משפחה	Hypothesis test	Hypothesis test
שנת המקור	1994	2002
הוגה השיטה	Reggiani & Schiaffino	Peter Aagaard
סוג	muscle biopsy analysis	isometric force measurement
מקור מכונן	Bottinelli, R., & Reggiani, C. (2000). Human skeletal muscle fibres: acting role of fibre type in resistance training. Journal of Sports Medicine and Physical Fitness, 40(2), 166-177.	Aagaard, P., Simonsen, E. B., Andersen, J. L., Magnusson, P., & Dyhre-Poulsen, P. (2002). Increased rate of force development and neural drive of human skeletal muscle following resistance training. Journal of Applied Physiology, 93(3), 1318-1326.
כינויים	fiber typing, myosin isoforms, muscle fiber classification	RFD, explosive strength, force development rate, strength impulse
קשורות	3	5
תקציר	MHC fiber typing is laboratory analysis of muscle fiber composition, quantifying the percentage of slow-twitch (Type I) and fast-twitch (Type II) fibers in a muscle sample. Based on myosin heavy chain (MHC) isoform expression, fibers are classified into Type I (slow-twitch, oxidative), Type IIa (fast-twitch, oxidative-glycolytic), and Type IIx/IId (fast-twitch, glycolytic). Introduced by Bottinelli and colleagues (1994), MHC typing requires muscle biopsy and biochemical analysis. Fiber type composition is partially genetic but trainable; endurance training promotes Type II-to-IIa conversion, while power training promotes Type I-to-IIa transitions in some contexts. Understanding fiber composition informs training prescription and explains performance predispositions.	Rate of force development (RFD) is the speed at which force is produced during the initial phase of muscle contraction, typically expressed as the slope of the force-time curve in the first 50, 100, or 200 milliseconds of isometric contraction. Introduced comprehensively by Aagaard and colleagues (2002), RFD is a measure of explosive strength capacity and neural drive efficiency. Unlike maximal voluntary strength (which captures peak force), RFD captures how quickly an athlete can generate that force—a critical quality in sports requiring rapid, explosive movements (sprinting starts, jumping, tackling). RFD improves dramatically with strength training, reflecting increased motor unit recruitment rate and firing frequency.