Just like with food, each person has a different kind and amount of sexual activity best for them. The general rules are that each constitution has a different amount of sex each month and then the recommendations are raised and lowered seasonally as well. Due to the ease in which vata dominant folks deplete, they do best with sexual activity just a few times a month. For Pitta dominant people the number doubles vata dominant. The ladies and gents with kapha constitution are cleared for the most sexual activity with multiple times a week being recommended.
Seasonally, the winter months and spring are the time where we are meant to keep warm by the side of a partner and have the most sex. It is when our bodies are the strongest and where we can expend the most kapha. In summer and early fall, our bodies are at their weakest and driest from the strong sun depleting our energy. This means that this is the time of year where we should conserve our vital force as opposed to constantly overdoing it.
An important thing to note is that you shouldn't hold back urges such as bowels movements, urinating, ejaculating, or sneezing so if you have a willing partner and a strong urge for sex then it is best you go for it. A pattern of not doing so can cause longterm problems in the reproductive organs, urinary system or digestive system. Engaging in morning sex before clearing the bowels or urinating also can create problems in those systems so if that is something you engage in and you experience frequent constipation or bladder infections then switch the order of your morning routine.
Many of the recommended Ayurvedic foods such as ghee, milk, almonds, figs and pomegranates build healthy sexual tissue. Drinking a glass of warm milk after sex is said to immediately replenish any lost energy. Adding an herb such as shatavari (women) or ashwaghanda (men) to your milk can have an even stronger effect.