When starting a new exercise plan you need to balance between making it too easy and forgetting about conditioning it or making it too hard and giving up out of frustration.
开始新的锻炼计划前，你必须在两者之间找到平衡点：要么太过容易忘记了调整；抑或太难了挫败多次而放弃。
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Aerobic exercise, a method of conditioning the cardiorespiratory system by using a variety of activities that create an increased demand of oxygen over an extended period of life.