Sewing activewear on the Brother Innov-is F420 with Fiona Parker

If, like me, you're attempting to get into a new-year exercise routine, you might be intrigued by the idea of sewing your own activewear, and once you've got the hang of sewing knits there's nothing to stop you doing so. It can be a lot of fun working with fabrics and techniques you might not need when sewing everyday clothing and you don't even need an overlocker. I've sewn a fair bit of it in the past but desperately needed some warmer leggings to encourage me to get running on cold winter mornings.

I resorted to an old favourite pattern to make these; the Pacific Leggings from Sewaholic. I have about three pairs of these that have been going strong for a couple of years. I love the seam lines and the shape of the waistband sits really comfortably, plus they have the practical bonus of a zip pocket at the rear. My other pairs are great for summer running and carry me through into slightly chillier weather, but I needed a pair for frosty mornings so chose this lovely thick merino blend double faced fabric in black from The Fabric Store.

These leggings were one of the first projects I tackled on my new Brother Innov-is F420 machine and it was a great way to get to grips with the stretch stitches it offers. I've always sewn knit fabrics on a regular machine before finishing seam allowances with my overlocker as I like the aesthetic of the overlocked stitches but find my sewing more accurate on the regular machine. It was a real treat to have a plethora of stretch stitch options to choose from rather than just a shorter/longer, wider/narrower zig zag! I tested out a variety on scraps of my fabric before I began and chose to use a combination of stitches throughout the project.

I used the no.16 overcasting stitch on seams which could be finished together, such as the inner and outer leg seams. After testing the stitches, this one appeared to have the greatest amount of stretch in the stitch and responded well to being stretched around the leg and the seam - a must for ensuring the leggings could cope with plenty of movement. What I particularly love about this option is the stitching is not visible from the right side. With a zig zag, particularly a wide one, the gaps between stitches can look quite obvious when the seam is stretched out, but this has a completely smooth finish like a straight stitch or what you might expect from an overlocked seam.

The seams to construct the waistband and zip pocket need to be pressed open to reduce bulk and for these seams I chose the no.57 triple straight stitch. This stitch looks like a thick straight stitch but is created by the needle going back and forth sewing three straight stitches next to each other. This back and forth motion gives the stitch some stretch in the same manner as a zig zag. It isn't super stretchy but perfect for these shorter seams which need some give and a lot of strength. The final stitch I used was the no.12 three-step zig zag stitch to attach the elastic. The manual that came with the machine handily lists all the stitches and the purposes they are best suited to and recommended this stitch for the job.

I love that the machine picks the optimum stitch width and length automatically for each stitch but you can still adjust them if you want. If you want to go back to the automatic settings, it is easy to remember what these originally were, as they are highlighted with a dark box on the screen as you scroll through the options.

One thing I will say about sewing with stretch stitches on the Innov-is F420 is that it has taken me a little while to get used to which stitches are accurate for the seam allowance guide on the needle plates. They are correct to follow when the needle is in the left-hand position but if you move it to the centre or use one of the zig zag or decorative stitches, it won't be an accurate guide anymore. The other thing to get used to is which stitches sew a backstitch and which stitches sew a reinforcing stitch on the spot when you press the reverse button. I've been carefully testing each stitch on a scrap and checking this and the seam allowance before I begin!

Now I'm getting used to it, I'm finding my favourite stitches and using them regularly. I've used pretty much only one machine for the last seven years but the motions of using this new machine have become instinctive and automatic surprisingly quickly!

The merino is quite a thick fabric, with a surprising amount of stretch and resilient recovery, so I'm looking forward to working with some fine and drapey knits to see how the machine and stitch selection handles those.

This particular fabric has a nylon underside too, making it a great choice for sports clothing when combined with the breathability of merino. The dense structure and spongy quality makes it completely opaque even when stretched and it has proved to be a great choice for a supportive pair of work out leggings. You could technically use either side of the fabric as the right side but I used the smooth, nylon side as the wrong side as it felt nicer against the skin. Also, this side gets a bit of a shine to it when stretched and I prefer a matte look on the exterior of my activewear. The pure merino side has more of a texture with an interesting, almost slubby finish.

I used Maderia Aeroflock thread (similar to woolly nylon) in the bobbin to aid stretch in the seams. I've found my knit seams to be so much stronger since I've started using this thread; particularly helpful with close-fitting activewear which sees a lot of strenuous use and washing - no popped seams on these yet!

I find the thread works best when used in the bobbin for twin-needle top-stitching which, by the way, this machine does a treat! For once, I had no problems with tension and the detachable horizontal spool holder makes setup quick and easy. You can select the twin-needle function on the screen, which is great as the machine reminds you when you are not set up correctly to move on.

The success of this project and addition to my activewear wardrobe has certainly encouraged me to run a bit more. Although I must admit the desire to need and therefore be able to sew more activewear is what is motivating me the most!