user7290: I couldn't find this exact question asked before. 
What kind of exercise is recommended for better physical comfort and "endurance"/"stamina" when sitting in meditation; apart from the sitting itself? 
I usually sit in the half vajra position, which is quite comfortable and stable, but find it a bit tiring when I sit for many hours. 
Any good exercises in "the long run"? Any good stretching or other exercises between sessions when sitting whole days? 

user5191: Sorry for being something of a jerk , man. I just had one of those days :p
so to actually answer your question, it does depend on which tradition we're talking about.
I know some (all?) traditions within Tibetan Buddhism teach yoga/stretches, these kind of things.
Within the Theravada, stretching, yoga, exercise in general is not considered part of the practice, as far as formal meditation goes.
So from a Theravada perspective, I would submit to you that your best course of action would be to 
1) Not solely sit for extended periods, much less an entire day. I've done this before at Goenka retreats, and I've found personally my meditation is much more productive when sitting is balanced with walking. I would also refer you to Ven. Yuttadhammo's answer to my question here 

The Buddha did in fact teach just this practice:
Bhikkhus, you should train thus: ‘We will be devoted to wakefulness. During the day, while walking back and forth and sitting, we will purify our minds of obstructive states. In the first watch of the night, while walking back and forth and sitting, we will purify our minds of obstructive states. In the middle watch of the night we will lie down on the right side in the lion’s pose with one foot overlapping the other, mindful and fully aware, after noting in our minds the time for rising. After rising, in the third watch of the night, while walking back and forth and sitting, we will purify our minds of obstructive states.’
-- MN 39 (Bodhi, trans)
  This passage occurs frequently in the suttas. The Buddha taught there are five benefits to walking meditation:
addhānakkhamo hoti - one is able to tolerate long-distance travel
padhānakkhamo hoti - one is able to tolerate exertion
appābādho hoti - one has little sickness
asitaṃ pītaṃ khāyitaṃ sāyitaṃ sammā pariṇāmaṃ gacchati - what is eaten, drunk, chewed and tasted goes to proper digestion
caṅkamādhigato samādhi ciraṭṭhitiko hoti - walking-produced concentration is of long duration.
  -- AN 5.29

2) Meditate on the feeling of tired. Again, I'm not sure what personal practice you undertake, but within my practice it would be as simple as taking up the feeling as the object of meditation and noting "Tired, tired". 
There's nothing really wrong with being tired, its just another transient state. The more you fight it, however, the more it will bite back :P You must bring about a clear awareness of it, look at how your mind reacts to it. It's nothing to go out of your way to stop arising, just like anything else. I hope this is actually of some use to you. Best of luck, be well.

user-1: The single best stretch you can do is the straddle stretch.  The linked video is pretty fantastic in that it not only shows you the ideal, but also the progression leading up to it.  Honorable mention goes to the frog pose.  I also really like this sequence from Kelly Starrett.  Ultimately, what you are going to want to pay attention to is hip mobility.  Most meditators experience pain in the knees and back and tend to focus on stretches and exercises that target those two areas.  Unbeknownst to them, what's really at issue is hip and psosas tightness.  The pain they experience is a symptom of a problem farther up along the movement chain; it's being caused by the body trying to adapt to a less than ideal condition imposed by poor mobility elsewhere.  Loosen up those other areas and the discomfort will lessen significantly. 
And for the record, meditating for long periods of time should make you tired.  That's kind of the point.  ;-)

7290: <p>I couldn't find this exact question asked before. </p>

<p>What kind of exercise is recommended for better physical comfort and "endurance"/"stamina" when sitting in meditation; apart from the sitting itself? 
I usually sit in the half vajra position, which is quite comfortable and stable, but find it a bit tiring when I sit for many hours. </p>

<p>Any good exercises in "the long run"? Any good stretching or other exercises between sessions when sitting whole days? </p>
 5191: <p>Sorry for being something of a jerk , man. I just had one of those days :p</p>

<p>so to actually answer your question, it does depend on which tradition we're talking about.</p>

<p>I know some (all?) traditions within Tibetan Buddhism teach yoga/stretches, these kind of things.</p>

<p>Within the Theravada, stretching, yoga, exercise in general is not considered part of the practice, as far as formal meditation goes.</p>

<p>So from a Theravada perspective, I would submit to you that your best course of action would be to </p>

<p>1) Not solely sit for extended periods, much less an entire day. I've done this before at Goenka retreats, and I've found personally my meditation is much more productive when sitting is balanced with walking. I would also refer you to Ven. Yuttadhammo's answer to my question <a href="https://buddhism.stackexchange.com/questions/10410/mahasi-sayadaw-walking">here</a>  </p>

<blockquote>
  <p>The Buddha did in fact teach just this practice:</p>
  
  <p>Bhikkhus, you should train thus: ‘We will be devoted to wakefulness. During the day, while walking back and forth and sitting, we will purify our minds of obstructive states. In the first watch of the night, while walking back and forth and sitting, we will purify our minds of obstructive states. In the middle watch of the night we will lie down on the right side in the lion’s pose with one foot overlapping the other, mindful and fully aware, after noting in our minds the time for rising. After rising, in the third watch of the night, while walking back and forth and sitting, we will purify our minds of obstructive states.’</p>
  
  <p>-- MN 39 (Bodhi, trans)
  This passage occurs frequently in the suttas. The Buddha taught there are five benefits to walking meditation:</p>
  
  <p>addhānakkhamo hoti - one is able to tolerate long-distance travel</p>
  
  <p>padhānakkhamo hoti - one is able to tolerate exertion</p>
  
  <p>appābādho hoti - one has little sickness</p>
  
  <p>asitaṃ pītaṃ khāyitaṃ sāyitaṃ sammā pariṇāmaṃ gacchati - what is eaten, drunk, chewed and tasted goes to proper digestion</p>
  
  <p>caṅkamādhigato samādhi ciraṭṭhitiko hoti - walking-produced concentration is of long duration.
  -- AN 5.29</p>
</blockquote>

<p>2) Meditate on the feeling of tired. Again, I'm not sure what personal practice you undertake, but within my practice it would be as simple as taking up the feeling as the object of meditation and noting "Tired, tired". </p>

<p>There's nothing really wrong with being tired, its just another transient state. The more you fight it, however, the more it will bite back :P You must bring about a clear awareness of it, look at how your mind reacts to it. It's nothing to go out of your way to stop arising, just like anything else. I hope this is actually of some use to you. Best of luck, be well.</p>
 -1: <p>The single best stretch you can do is <a href="https://www.youtube.com/watch?v=QjaQj2S2G_E">the straddle stretch.</a>  The linked video is pretty fantastic in that it not only shows you the ideal, but also the progression leading up to it.  Honorable mention goes to the <a href="https://youtu.be/KKLRpTXA3k0">frog pose</a>.  I also really like <a href="https://youtu.be/JBHzXF-mVjY">this sequence</a> from Kelly Starrett.  Ultimately, what you are going to want to pay attention to is hip mobility.  Most meditators experience pain in the knees and back and tend to focus on stretches and exercises that target those two areas.  Unbeknownst to them, what's really at issue is hip and psosas tightness.  The pain they experience is a symptom of a problem farther up along the movement chain; it's being caused by the body trying to adapt to a less than ideal condition imposed by poor mobility elsewhere.  Loosen up those other areas and the discomfort will lessen significantly. </p>

<p>And for the record, meditating for long periods of time should make you tired.  <a href="https://albertlow.wordpress.com/2014/02/01/sitting-long-and-getting-tired/">That's kind of the point.</a>  ;-)</p>
