I have been unable to find an answer to my question with an internet search, so I thought this would be the best place to find the answer to my question.
Does the body weight of a client influence the resistance experienced during an exercise on the reformer?

Hi Kami...yes, absolutely but in some exercises more than others. For example if I am teaching a class the Long Stretch on the reformer a 105 lb female will feel this very differently from a 175lb female. I might then use a red spring for the lighter person and a red and blue spring for the heavier person. Now, of course strength plays a big role too. If someone is stronger they may be able to do lighter (red) or stronger in the upper body maybe red and blue. This is why it's so important to know generally which exercises recommend which springs and then practice with various clients to see how it all applies. Now supine feet in straps may not need as much variation because body weight isn't as much of a factor as strength and control is. I hope that helps!