It always seems to me that I run into two kind of people when it comes to ascetical labors. One person tries to do too much too soon, and quickly becomes disgusted with themself and thereafter does little. Another person does very little, out of fear, and again remains in the same position. Oddly, the end of both is the same. We would do better to add humility to our fasting, to our prayers and not drive ourselves crazy.
From St. Seraphim of Sarov:
One should not undertake ascetic labors beyond one’s measure, but one should strive to make our friend – the flesh – faithful and capable of performing virtues.
One should go by a middle path: turn not aside to the right hand nor to the left (Prov. 4:27); and one should render unto the spirit what is spiritual, and unto the body what is bodily; for the maintenance of temporal life, one should render what is necessary, and for life in society, that which si lawfully demanded by it, in accordance with the words of Holy Scripture: Render unto Caesar the things that are Caesar’s, and unto God the things that are God’s (Matt. 22:21).
One must condescend to the soul in its infirmities and imperfections, and bear its defects as we bear those of others; one must not, however, become lazy, but should spur oneself to do better.
Perhaps one has eaten too much, or done something similar to this which is natural to human weakness – do not be disturbed at this, and do not add injury to injury; but bestire yourself to correction and at the same time strive to preserve peace of soul, according to the word of the Apostle: Blessed is he that condemneth not himself in that thing which he alloweth (Rom. 14:22).
The same thoughtis contained in the words of the Savior: Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven (Matt. 18:3).
If the body has been worn out by ascetic labors or sickness, one should strengthen it with moderate sleep, food, and drink, not observing even the times. Jesus Christ, after the raising of Jairus’ daughter, immediately commanded: Give her to eat (Lk. 8:55).
Every success in anything we should refer to the Lord and with the Prophet say: Not to us, O Lord, not to us, but to Thy name give glory (Ps. 113:9).