One who lives a life of repetition and routine will almost inevitably become a victim of boredom, especially since man by his very nature tires from a lack of change. For this reason Allah, the Exalted, the Almighty, gave us variety in times and places, in food and drink - diversity in the many forms of creation: night and day, valley and mountain, white and black, hot and cold, shade and sun, sweet and sour.
Allah mentioned this diversity in His book:
(There comes forth from their bellies, a drink of varying color)
(Qur'an l6: 69)
(…and date-palms, growing out two or three from a single stem root, or otherwise [one stem root for every palm) (Qur'an I3:4)
(And crops of different shape and taste [its fruits and its seeds] and olives, and pomegranates, similar [in kind] and different [in taste].)
(Qur'an 6: 141)
(And among the mountains are streaks white and red, of varying colors)
(Qur'an 35: 27)
(And so are the days [good and not so good], We give to men by turns...) (Qur'an 3: 140)
The children of Israel tired of eating the one kind food they were given, even though it was the best of foods - simply because it was all that they ate.
(We cannot endure one kind of food) (Qur'an 2: 61)
Al-Ma'moon would alternate between reading, standing, sitting, or lying, and he said,
"The soul is ever so prone to boredom."
(Those who remember Allah [always, and in prayers] standing, sitting and lying down on their sides) (Qur'an 3: 191)
You should contemplate the many forms of worship that are legislated in Islam. There are deeds of the heart, of the tongue, of the limbs, and of wealth- by spending it for a good cause. The prayer, alms giving, fasting, pilgrimages to Makkah, fighting in the way of Allah --- these are only some examples of worship. The prayer involves standing, bowing, prostrating, and sitting. If you desire relaxation, vitality, and continued productivity, then bring diversity into your work, your reading, and your daily life. In terms of reading, for example, read a broad range of topics: the Qur'an, its explanation, the biography of the Prophet (Blessings and Peace be upon him) and his Companions, hadith, Islamic jurisprudence, history, literature, books of general knowledge, and so forth. Distribute your time between worship and enjoying what is lawful, from visiting friends, entertaining guests, playing sports, or going on excursions: you will find yourself to be a lively and bright person, because the soul delights in variety and things that are new.