...so some adaptation is in order...
No problem with the meditation of course. My trusty Insight Timer app gives me a gentle gong to start the 20 minutes and another to end. If you don't know this app I recommend it. It has hundreds of guided relaxation/meditation options as well as the timer which you can set to whatever times and sounds you wish. The guided options are from various religious and secular perspectives. If you are wanting guidance with Centering Prayer there is a very good 30 minute track with an introduction, then 20 minutes silence and ends with a beautiful contemporary version of the Lord's Prayer. (Search 'centering prayer').
To get my body going on a 'no walk' morning I'm using a 20 minute Qi Gong routine on You Tube. (There is also a 10 minute version of the same routine.) Qi Gong is a very integrated mind/body practice so for me this is more than just 'exercises'.
(I don't quite look like this yet .... but with enough wet days - who knows!!)