Many people come in to my clinic and when we get on to the subject of core strength, they say "yeah I think my core is pretty strong". I ask them about Planks and they reckon they can hold it for 20, 30 even 60 seconds. When we get on the floor and actually do them though, it's a different matter. People are sometimes shocked and disappointed by how little they can do. What you used to be able to do isn't helping your back right now!
So let's start with wherever you are and build from there. If you can hold it 10 seconds, let's try and get you to 15 seconds and so on. Imagine if you could hold it 60 seconds and do that 3 times! Doing that 3 times a week alongside your aerobic exercises will help your back out no end.
Side planks make sure we work different core muscles. They are a little harder so you'll be forgiven if you can't do 3 sets of 60 seconds. Let's set the bar at 45 seconds for this one but still do it 3 times a week.