قارن الطرق

	نسبة التبادل التنفسي	عتبة اللاكتات (OBLA)
المجال	علوم الرياضة	علوم الرياضة
العائلة	Hypothesis test	Hypothesis test
سنة النشأة	1949	1973
صاحب الطريقة	J. B. Weir	Klaus Wasserman
النوع	expired gas analysis	incremental blood sampling test
المصدر التأسيسي	Weir, J. B. (1949). New methods for calculating metabolic rate with special reference to protein metabolism. Journal of Physiology, 109(1-2), 1-9.	Wasserman, K., Whipp, B. J., Koyal, S. N., & Beaver, W. L. (1973). Anaerobic threshold and respiratory gas exchange during exercise. Journal of Applied Physiology, 35(2), 236-243.
الأسماء البديلة	RER, respiratory quotient, RQ, substrate oxidation ratio	OBLA, anaerobic threshold, lactate turnpoint, maximal lactate steady state
ذات صلة	5	5
الملخص	The respiratory exchange ratio (RER), also called the respiratory quotient (RQ), is the ratio of carbon dioxide produced to oxygen consumed during metabolism. Introduced by J. B. Weir (1949), RER is a non-invasive indirect measure of substrate utilization—indicating whether the body is primarily oxidizing carbohydrate, fat, or protein. RER values range from approximately 0.7 (pure fat oxidation) to 1.0 (pure carbohydrate oxidation) and higher under anaerobic conditions. By measuring exhaled and inhaled gases during exercise, RER reveals which fuel source predominates at different intensities, providing insights into metabolic flexibility and exercise physiology.	Lactate threshold, also termed the onset of blood lactate accumulation (OBLA), is the exercise intensity at which blood lactate concentration increases rapidly and non-linearly. Initially defined by Klaus Wasserman in 1973, the concept describes the physiological transition from aerobic to anaerobic metabolism. As exercise intensity increases, lactate production and clearance remain balanced until a critical threshold is exceeded, after which lactate rapidly accumulates in the blood, signaling a shift toward anaerobic energy pathways. This parameter is crucial in endurance sports and clinical exercise assessment.