Mild exercise, that is, as weight lifting and other strenuous activities can make things worse.
Mild exercise that can help alleviate lower back pain begins and ends with stretching.
From our extensive experience we can say that without a doubt the no. 1 exercise to get rid of lower back pain without risking an in injury is cat pose or Marjariasana.
Cat pose will gently massage your lower back muscles without imposing any further strains and it is super easy to perform.
Get on all fours into a table-like position with your hands directly underneath your shoulders and knees at hip-width apart. Look straight in front of you and as you inhale, tilt your head back and raise your tailbone. Hold this position for a couple of seconds and as you exhale, touch your chest with your chin and arch your back up towards the ceiling as high as you can. Hold here for a few seconds and bring the pose back into a table-like position.
Repeat this exercise a few times or as long as it feels comfortable. You will feel your lower back muscles relaxing and your pain disappearing.