Master the science of concurrent training before you master the practice.Most coaches understand that athletes need multiple physical qualities simultaneously. But they don't understand why concurrent training is so challenging-or how to make it work.The problem: Interference. When you train strength on Monday and endurance on Wednesday, one quality can inhibit adaptation in the other. Your nervous system, hormones, and energy systems face conflicting demands. The result? Both qualities progress slower than if you trained them separately.But interference can be minimized with the right knowledge.Concurrent Training Foundations provides the scientific foundation every coach needs: Part 1: Physiological FoundationsHow energy systems work (PCr system, anaerobic glycolytic, aerobic oxidative)How muscles actually adapt to training (stimulus → response → adaptation)How the nervous system responds to different training stressesWhy concurrent training creates unique physiological demandsPart 2: The Interference EffectWhat interference is and why it occurs (4 distinct mechanisms)Research evidence on interference magnitudeWhen interference becomes a serious problemStrategic approaches to minimizing interferenceIndividual differences in interference susceptibilityStrategic OverviewThe complete logic chain from physiology to practiceHow to think about concurrent training systematicallyConceptual framework for all subsequent learningThis is not a quick read. It's deep, evidence-based science. But it's written for coaches, not researchers. You'll understand: WHY interference occursHOW much it mattersWHAT research shows about minimizing itHOW this knowledge changes your coaching decisionsRead this first. Master the foundation. Then everything else makes sense.The Concurrent Training System: Volume 1 of 3