Well, they’re certainly transcending something! Apparently they do it to overcome PTSD. I hope it helps.
Anyway, I apologize for the diversion, back to your problem.
The most practical advice on this in the suttas is at AN 7.61, where the Buddha gives a series of teachings to Moggallāna, who before his awakening was struggling with the same issue.
In addition to these, take care to only meditate when you are well rested. And it doesn’t hurt to have a nice cup of coffee before you sit.
If you’re doing buddho meditation, try applying yourself with a little more clarity and strength to the recitation. Do it a bit faster and a bit louder in your head. Not too much, just enough so there’s an edge on it. You can settle into peace later on.
If you’ve tried all these, the method I suggest is to reduce meditation time in one posture. Sit for no more than 5 minutes, then stand up. If you can walk, great, if not, just stand for 5 minutes. Then sit again. Do this for your whole meditation session. Don’t do any longer sits. Keep doing this for several weeks, until you have conditioned your mind to be always awake in meditation. If 5 minutes is too long, make it 2 minutes, or one minute. It doesn’t matter how long it is, only that you don’t get drowsy.
Once you are very comfortable and confident with this, start to gradually extend the length of the sitting periods. If at any time you find yourself getting drowsy, shorten the sits once more.
Remember, the value of your meditation is not the amount of time you spend sitting, but the quality of your mindfulness. Don’t compare yourself with other meditators: everyone has their own issues.
I hope these things can help. Be patient, it may take some time. But you’ll get there.
Lots of good advice above- I don’t want to add to noise by repeating it!
I have found having ‘micro-sleep’ episodes when meditating quite refreshing. As you are sitting up it isn’t really possible to fall into a deep sleep -unless you are trained soldier, like in article posted by Ajhan Sujato .
Its possible to sometimes have a really good meditation after the micro-sleep takes the tiredness away. So even if you are sleepy, do think of continuing as you may have a good meditation session afterwards. Don’t develop an aversion towards the sleepiness!
First make sure you sleep enough at night and if needed as the Buddha did have a nap during the day.
Second sloth and torpor is often due to boredom. Change your approach to meditation and become curious about what’s going on rather than trying to achieve anything by meditating.
Its not serious or life threatening, and can get better with time apparently. People who have conditions on the long term often see it as being a normal variation, but things can be improved. I had a friend with this condition- he is much better with treatment now. There might be the possibility having meditation sessions where you are much more alert.
Except if it happens when you’re driving or operating heavy machinery! A friend of mine gave up her drivers license after a few scary and potentially life threatening incidents.
Definitely worth checking out!
There’s so much wonderful advice already given here, including possible medical solutions. It’s such a great resource for others struggling with this hindrance. I hope you don’t mind if I edit the title so it’s clear what the hindrance is - there might be someone else out there who might be more likely to read this topic, who really might benefit, as a result of this small change. Anumodana for your very useful question!!
Also, I was thinking about your question again today and it ocurred to me to ask you how long this has been happening for and if you are new to meditation, whether this happens all the time or whether you go through phases where it happens for a period of time and then goes away?
With metta and many thanks for asking this wonderful question.