摘要
            
            Training means engaging in activity to improve performance and/or fitness; this is best accomplished by understanding general sports training principles: overload, reversibility, progression, individualization, periodization, and specificity. Overload Description: The exposure of tissues to greater than accustomed-to training stress (1,2). Concept: Challenging current fitness/performance levels induces compensatory improvements (1). However, excessive overload and/or inadequate rest can result in overtraining, injury, and performance decrements (2). Example: A jogger runs faster than her normal pace with hopes of improving endurance. Reversibility Description: The observation that withdrawal of tissue loading results in loss of beneficial fitness/performance adaptations (1). Concept: The body adapts to cessation of a specific activity and inadequate training load with atrophy and fitness/performance decrements (1). Example: A body builder laments his loss of muscular gains after taking a 2-wk vacation. Progression Description: The gradual and systematic increases in training stress to maintain tissue overload and, thus, provoke continued training adaptation (2). Concept: As fitness/performance improves with training, training variables (i.e., frequency, intensity, volume) must be increased to induce further adaptation. Rate of progression is important; progressing too rapidly can result in injury while progressing too slowly will delay goal attainment (2). Example: A weight lifter can comfortably lift a weight that used to be a challenge, so she must now lift heavier weights to continue gaining strength. Individualization Description: The modification of training to account for an athlete's unique capacity for and response to training (2,3). Concept: A training program should acknowledge differences in an athlete's capacity for adaptation from that of their teammates, in order to ensure adherence to training principles for that individual; this capacity is affected by physiologic (e.g., age, current fitness, training history), psychologic (e.g., effort, confidence), environmental (e.g., nutrition, lifestyle habits), and genetic factors (2,3). Example: The workout program for a freshman quarterback differs necessarily from that of a senior lineman on his football team, based on individual differences. Periodization Description: The planned systematic and structural variation of a training program over time (1,4,5). Concept: Constant cycling of training variables (activity, rest, frequency, intensity, duration) within a training program each day, week, and month aims to maintain optimal training stimulus, address changing goals and individual variability, and avoid overtraining, injury, and burnout; this is often implemented using microcycles, mesocycles, and macrocycles (training cycles within training cycles of increasing duration) as a framework (1,4,5). Example: A lacrosse team's training program is altered across macrocycles to keep adaptations aligned with the varying goals of the preseason, in-season, and off-season (2,3). Specificity Description: The observation that fitness/performance improves through training movement patterns and intensities of a specific task and fitness type (strength, power, endurance, or flexibility) (2). Concept: Incorporating specific tasks of a sport will induce neuromuscular and metabolic adaptations to improve specific structure, fitness, and exercise economy of the overloaded muscle groups (4). Training should be directed at improving the fitness/performance of a sport's distinct key components. Example: While power athletes should train power and endurance athletes should train endurance (e.g., swimmers should swim), team sports athletes require training with a combination of these two types of fitness, as well as sport-specific movements/skills (3).