Sri M said ...

Sadhana cannot cause tiredness, when you are connected with your inner energy. If you are getting exhausted, you need to look at your whole day and see what activity you are engaged in - what have you been eating or what kind of society you are mixing with. When that clashes with your meditative state, it can cause tiredness. So avoid it, and then you'll see you are full of energy, even when you practice sadhana.