Practice intensely,
3. 集中练习。
without interruption for short periods of no longer than 90 minutes and then take a break.Ninety minutes appears to be the maximum amount of time that we can bring the highest level of focus to any given activity. The evidence is equally strong that great performers practice no more than 4 ½ hours a day.
持续无间断的不超过90分钟的短周期练习，然后再休息。90分钟是我们能高度集中于一个特定活动的最持久的时间。大量证据表明优秀的执行者每天的练习不超过四个半小时。