High training workloads alone do not cause sports injuries: how you get there is the real issue
Clinicians or strength and conditioning professionals who prescribe training workloads aim for workloads that are high enough to improve fitness (ie, performance) but not so high as to risk injury. At the extremes, no training results in an unprepared athlete, whereas an overuse injury is, by definition, an error in training prescription.1 Banister et al 2 first described an athlete's training state as the difference between positive (ie, 'fitness' and negative (ie, 'fatigue' influences. To quantify this concept, 'fitness' was represented as the workload (an arbitrary 'training impulse' of the athlete over a 3 6 weeks period and 'fatigue' was represented by the workload performed over a shorter time frame of 1 week. We recommend the terms 'chronic workload' for the longer window of training (ie, Banister's 'fitness' and 'acute workload' for the immediate window of training (ie, Banister's 'fatigue' (figure 1) High chronic workloads (ie, intense training) combined with reductions in acute workloads before important competition (ie, taper) would be expected to improve sporting performance.2 Figure 1 Acute and chronic workloads and the calculation of the acute:chronic workload ratio as a
British Journal of Sports Medicine