Dominance of Doshas In Day, Seasons, Lifetime

The three Doshas – Vata, Pitta and Kapha become dominant in three parts in day, night, seasons and also in our lives.

Distribution of Tridosha in body and in a day. 

In the last post of Ashtanga Hrudaya, we learnt about basics of Ayurveda. One of it explains how Tridoshas dominate in particular times of day and in particular parts of body.

Funda: The idea is that, whenever a Dosha is dominant, do the things that are opposite to the Dosha, so as to keep it in balance. Tridosha are the three factors that control our health and disease. They are – Vata, Pitta and Kapha. Balance of Tridosha leads to health and imbalance in Tridosha is disease.

Tridosha domination as per age

In childhood and adolescence – Kapha is dominant. This is why children often suffer from indigestion and respiratory problems.

Hot water bath is good for children. Because, cold is a quality of Kapha, Kapha is already dominant in children, hence cold water bath tends to bring in or worsen respiratory problems.

In elders, (after 50 years of age), Vata is dominant. Hence, it is specially advised for elders to take regular oil massage, which helps to keep Vata in a balanced condition, thereby avoiding arthritis, osteo-porosis etc.

Tridosha dominance in body parts

They are present all over the body. But their presence is especially observed as follows –
Vata dominates – in lower abdomen, and lower limbs. This means, locomotor action, defecation, urination, menstrual periods, and child birth are influenced by Vata. Osteo-arthritis, is caused due to Vata, and is known to affect the lower back and joints.
Pitta dominates – In the middle part of the body. This means, all the digestion and metabolism is influenced by Pitta activity.
Kapha dominates – In the chest and upper part of the body. This means, some functions of brain, respiratory activity, etc are influenced by Kapha.

Tridosha dominance in day and night

In a day: The first part is dominated by Kapha, the afternoon hours are dominated by Pitta and evening hours are dominated by Vata.

At night: The first, second and third part are dominated by Kapha, Pitta and Vata respectively.

So, the last part of the night, just before sunrise is dominated by Vata. Hence it is ideal to wake up at this time. Vata refers to movement and activity. If you get up in these early morning hours, you will be active throughout the day. There are also other benefits of waking up early in the morning.

Once after the sunrise, Kapha is dominant. Kapha refers to heaviness. Hence, if you get up late in the morning, you may feel heavy and lazy throughout the day.

Tridosha dominance during digestion

The early stage, mid stage and end stage are dominated by Kapha, Pitta and Vata respectively.
That means, soon after food intake, there is an increase of Kapha. This is why, you tend to have salivation, heaviness, and lethargy soon after food intake.
During this time, if you walk for a short distance, or keep the body and mind active, Kapha will be balanced and will help in easy digestion.
After dinner, there is kapha dominance and first part of night is again kapha dominant. So during this time, the digestion power will be less. Hence, having a light dinner always helps to maintain the balance. Also, it is better to avoid oily food, ice creams, sweets and such other Kapha increasing food at night. Hence, always have a limit on what you eat at night.

So, these are a few examples to take precautions during the time of Dosha domination.

Vata in Morning, Night

Vata gets aggravated in the evening so we have a lack of energy to exercise. 
You have also written that Vata is more in the brahmi muhurta last part of night or early morning, so there is great energy and enthusiasm to exercise. Aren’t these two statements contradictory? 

If we divide the day and night into three parts, the last part of both day and night is dominated by Vata Dosha. That is why, in the last part of night (Brahmi Muhurtha time – 4- 5 am) in the last part of the night, there is Vata Dosha increase.
Though there is Vata increase in both these timings, there is slight difference between the two.
Movement and activity are the functions of Vata Dosha. Throughout the day, due to our various physical activities, Vata Dosha slowly gains momentum in the body and gets aggravated in the evening hours. Because the body has been active throughout the day, one gets tired at night.

Nearing Brahmi muhurtha also, there is Vata Dosha increase. But this is not due to hyperactivity of the body. This is largely due to the completion of digestion activity and formation and storage of urine and feces (both of which are controlled by Vata Dosha). There is no tiredness here as the body has rested well without any activities. 
Master Vagbhata, in Ashtanga Samhita Sutrasthana 3rd chapter, writes,
 ब्राह्मे मुहूर्ते उत्तिष्ठेज्जीर्णाजीर्णं निरूपयन् ।
रक्षार्थमायुषः स्वस्थो जातवेगः समुत्सृजेत् ॥ 
brāhme muhūrte uttiṣṭhejjīrṇājīrṇaṃ nirūpayan |
rakṣārthamāyuṣaḥ svastho jātavegaḥ samutsṛjet ||
It is told that – One should wake up at Brahmi muhurtha, after watching the signs of digestion of food (lightness of abdomen and body, clear belching without any odor etc.) and then should attend to his natural urges (washroom business).