There are other wearing options but I wanted to wear it on my wrist but couldn't afford a better strap so went about constructing a new one from fabric.
I'm so pleased with the result I wanted to share the tutorial for other sewing enthusiasts to use or adapt for their own activity trackers.
Step 1: Items Needed
1 piece of fabric measuring 16cm wide by 28cm long.
1 piece hook tape measuring 5cm long.
1 piece loop tape measuring 5cm long.
Thread to contrast or match.
Step 2: Pressing Folds
Fold the fabric in half along the long edge, press and open.
Fold the raw long edges of the fabric in to the middle and press.
You should now have a piece of fabric 4cm wide and with all raw edges hidden. When opened out it should look a bit like a book.
Step 3: Add a Buttonhole
Choose a side for your buttonhole. Mark the halfway point in the length of the strip and measure 2cm in from the folded edge on your chosen side. You should now have marks that look something like a cross.
Measure 1.5 cm in each direction from the centre length line and draw a line. You should now have markings on one half of your fabric strip which looks like --|-|-|--.
Sew a 3cm buttonhole between the 2 end lines. This should be parallel with the long edges of the strip, not across the width.
Step 4: Sewing the Edges
It should only be through one layer, so that you can see the lights of your activity tracker through the fabric.
Fold the fabric. Strip again so the raw edges are hidden. Press.
Pin and sew around all four edges using a 0.25cm seam.
Step 5: Adding the Hook and Loop
Attach the loop tape to the side of the strap with the buttonhole. This is so it won't rub or scratch your skin if some comes in to contact with your wrist.
Attach the hook tape to the side of the strap without the buttonhole and at the opposite end to the loop tape.
Secure both in place with stitches.
Step 6: Creating a Pocket
Draw two lines across the end of the buttonhole. These should be roughly 3.5cm away from one another.
Stitch across the lines you just drew. Now you should have a small square box around the buttonhole, measuring 3.5cm x 3.5cm.