user8157: The Satipatthana Sutta begins in the following manner:

"And how does a monk remain focused on the body in & of itself?
"There is the case where a monk — having gone to the wilderness, to the shade of a tree, or to an empty building — sits down folding his
  legs crosswise, holding his body erect and setting mindfulness to the
  fore [lit: the front of the chest]. Always mindful, he breathes in;
  mindful he breathes out.
"Breathing in long, he discerns, 'I am breathing in long'; or breathing out long, he discerns, 'I am breathing out long.' Or
  breathing in short, he discerns, 'I am breathing in short'; or
  breathing out short, he discerns, 'I am breathing out short.' He
  trains himself, 'I will breathe in sensitive to the entire body.' He
  trains himself, 'I will breathe out sensitive to the entire body.' He
  trains himself, 'I will breathe in calming bodily fabrication.' He
  trains himself, 'I will breathe out calming bodily fabrication.' Just
  as a skilled turner or his apprentice, when making a long turn,
  discerns, 'I am making a long turn,' or when making a short turn
  discerns, 'I am making a short turn'; in the same way the monk, when
  breathing in long, discerns, 'I am breathing in long'; or breathing
  out long, he discerns, 'I am breathing out long' ... He trains
  himself, 'I will breathe in calming bodily fabrication.' He trains
  himself, 'I will breathe out calming bodily fabrication.'

Later, the Satipatthana Sutta says:

And how does a monk remain focused on the mind in & of itself? There is the case where a monk, when the mind has passion, discerns that the
  mind has passion. When the mind is without passion, he discerns that
  the mind is without passion. When the mind has aversion, he discerns
  that the mind has aversion. When the mind is without aversion, he
  discerns that the mind is without aversion. When the mind has
  delusion, he discerns that the mind has delusion. When the mind is
  without delusion, he discerns that the mind is without delusion.
"When the mind is constricted, he discerns that the mind is constricted. When the mind is scattered, he discerns that the mind is
  scattered. When the mind is enlarged, he discerns that the mind is
  enlarged. When the mind is not enlarged, he discerns that the mind is
  not enlarged. When the mind is surpassed, he discerns that the mind is
  surpassed. When the mind is unsurpassed, he discerns that the mind is
  unsurpassed. When the mind is concentrated, he discerns that the mind
  is concentrated. When the mind is not concentrated, he discerns that
  the mind is not concentrated. When the mind is released, he discerns
  that the mind is released. When the mind is not released, he discerns
  that the mind is not released.

Then later, again, the Satipatthana Sutta says:

"And how does a monk remain focused on mental qualities in & of themselves?
"There is the case where a monk remains focused on mental qualities in & of themselves with reference to the five hindrances. And how does
  a monk remain focused on mental qualities in & of themselves with
  reference to the five hindrances? There is the case where, there being
  sensual desire present within, a monk discerns that 'There is sensual
  desire present within me.' Or, there being no sensual desire present
  within, he discerns that 'There is no sensual desire present within
  me.' He discerns how there is the arising of unarisen sensual desire.
  And he discerns how there is the abandoning of sensual desire once it
  has arisen. And he discerns how there is no future arising of sensual
  desire that has been abandoned. (The same formula is repeated for the
  remaining hindrances: ill will, sloth & drowsiness, restlessness &
  anxiety, and uncertainty

Now the problem I have with practising according to the Satipatthana Sutta is when I practise the first part (remain focused on the body in & of itself) there are no mental defilements and no five hindrances to observe. Therefore, how can practise everything said in the Satipatthana Sutta when the mind has no hindrances if I practise the first body section very well? 

user111: There's a high chance you might be just practicing Samatha instead of Vipassana.
When you sit for meditation, If you feel a pain, itching or any other sensation on the body, being mindful of those is Vedananupassana. In Samatha you just ignore those and focus on the breath. That's not Vipassana.
If the mind starts to wander, thinking of past/present/future thoughts or if it becomes focused, being mindful of those mental activities is Cittanupassana. In Samatha you just ignore those and focus on the breath. That's not Vipassana.
If you hear a sound, smell etc. or if desire, aversion, laziness etc. arise in the mind, being aware of them is Dhammanupassana. In Samatha you just ignore those and focus on the breath. That's not Vipassana.

8157: <p>The <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.010.than.html" rel="nofollow noreferrer">Satipatthana Sutta</a> begins in the following manner:</p>

<blockquote>
  <p><em>"And how does a monk remain focused on the body in &amp; of itself?</em></p>
  
  <p><em>"There is the case where a monk — having gone to the wilderness, to the shade of a tree, or to an empty building — sits down folding his
  legs crosswise, holding his body erect and setting mindfulness to the
  fore [lit: the front of the chest]. Always mindful, he breathes in;
  mindful he breathes out.</em></p>
  
  <p><em>"Breathing in long, he discerns, 'I am breathing in long'; or breathing out long, he discerns, 'I am breathing out long.' Or
  breathing in short, he discerns, 'I am breathing in short'; or
  breathing out short, he discerns, 'I am breathing out short.' He
  trains himself, 'I will breathe in sensitive to the entire body.' He
  trains himself, 'I will breathe out sensitive to the entire body.' He
  trains himself, 'I will breathe in calming bodily fabrication.' He
  trains himself, 'I will breathe out calming bodily fabrication.' Just
  as a skilled turner or his apprentice, when making a long turn,
  discerns, 'I am making a long turn,' or when making a short turn
  discerns, 'I am making a short turn'; in the same way the monk, when
  breathing in long, discerns, 'I am breathing in long'; or breathing
  out long, he discerns, 'I am breathing out long' ... He trains
  himself, 'I will breathe in calming bodily fabrication.' He trains
  himself, 'I will breathe out calming bodily fabrication.'</em></p>
</blockquote>

<p>Later, the <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.010.than.html" rel="nofollow noreferrer">Satipatthana Sutta</a> says:</p>

<blockquote>
  <p><em>And how does a monk remain focused on the mind in &amp; of itself? There is the case where a monk, when the mind has passion, discerns that the
  mind has passion. When the mind is without passion, he discerns that
  the mind is without passion. When the mind has aversion, he discerns
  that the mind has aversion. When the mind is without aversion, he
  discerns that the mind is without aversion. When the mind has
  delusion, he discerns that the mind has delusion. When the mind is
  without delusion, he discerns that the mind is without delusion.</em></p>
  
  <p><em>"When the mind is constricted, he discerns that the mind is constricted. When the mind is scattered, he discerns that the mind is
  scattered. When the mind is enlarged, he discerns that the mind is
  enlarged. When the mind is not enlarged, he discerns that the mind is
  not enlarged. When the mind is surpassed, he discerns that the mind is
  surpassed. When the mind is unsurpassed, he discerns that the mind is
  unsurpassed. When the mind is concentrated, he discerns that the mind
  is concentrated. When the mind is not concentrated, he discerns that
  the mind is not concentrated. When the mind is released, he discerns
  that the mind is released. When the mind is not released, he discerns
  that the mind is not released.</em></p>
</blockquote>

<p>Then later, again, the <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.010.than.html" rel="nofollow noreferrer">Satipatthana Sutta</a> says:</p>

<blockquote>
  <p><em>"And how does a monk remain focused on mental qualities in &amp; of themselves?</em></p>
  
  <p><em>"There is the case where a monk remains focused on mental qualities in &amp; of themselves with reference to the five hindrances. And how does
  a monk remain focused on mental qualities in &amp; of themselves with
  reference to the five hindrances? There is the case where, there being
  sensual desire present within, a monk discerns that 'There is sensual
  desire present within me.' Or, there being no sensual desire present
  within, he discerns that 'There is no sensual desire present within
  me.' He discerns how there is the arising of unarisen sensual desire.
  And he discerns how there is the abandoning of sensual desire once it
  has arisen. And he discerns how there is no future arising of sensual
  desire that has been abandoned. (The same formula is repeated for the
  remaining hindrances: ill will, sloth &amp; drowsiness, restlessness &amp;
  anxiety, and uncertainty</em></p>
</blockquote>

<p>Now the problem I have with practising according to the <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.010.than.html" rel="nofollow noreferrer">Satipatthana Sutta</a> is when I practise the first part (<em>remain focused on the body in &amp; of itself</em>) there are no mental defilements and no five hindrances to observe. Therefore, how can practise everything said in the <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.010.than.html" rel="nofollow noreferrer">Satipatthana Sutta</a> when the mind has no hindrances if I practise the first body section very well? </p>
 111: <p>There's a high chance you might be just practicing Samatha instead of Vipassana.</p>

<p>When you sit for meditation, If you feel a pain, itching or any other sensation on the body, being mindful of those is Vedananupassana. In Samatha you just ignore those and focus on the breath. That's not Vipassana.</p>

<p>If the mind starts to wander, thinking of past/present/future thoughts or if it becomes focused, being mindful of those mental activities is Cittanupassana. In Samatha you just ignore those and focus on the breath. That's not Vipassana.</p>

<p>If you hear a sound, smell etc. or if desire, aversion, laziness etc. arise in the mind, being aware of them is Dhammanupassana. In Samatha you just ignore those and focus on the breath. That's not Vipassana.</p>
