Berachos 32b

Gemara: "The Rabbis learned: The Chasidim HaRishonim would wait one hour (in preparation for prayer), pray for one hour, and then wait one more hour (coming out of the experiance, so to speak, through more prayers - like Ashrei U'va L'tzion that we say)." The gemara asks, "Since they spent nine hours during the day praying, how was their Torah protected and their work completed?" The gemara answers, "Since they were Chasidim, their Torah was protected and their work was blessed."
One could ask that to be consistant the gemara should have asked, "How was their Torah learned and their work completed?" The answer is that the gemara accepts the fact that they may not have been able to learn much more new Torah. However, (as we all know), Chasidim are made - not born. So, until a person reached the level of Chasidus he had time to learn. On that the gemara asks how was the Torah that he learned in the past protected, surely he would forget it.

Take a 24 hour day. Subtract 8 hours for sleep = 16. Subtract 9 hours for praying = 7. Subtract 2 hours for personal needs = 5. We see that the gemara considers that 5 hours is not long enough to review one's learning and also to work in.

Exactly what is the definition of a Chasid (in the times of the gemara)? Hmm...