1) How do I know which size fits me?

    Both Sub45 and Sub90 come in 2 sizes: XS-S and M-L-XL.  To find yours, measure 2 inches below the pectoral muscles/ band line. See how to measure here.  If you are borderline, consider thickness variations (jacket, etc.) between summer and winter runs.

    • XS/S =  26 in to 31 in (67 cm to 78 cm)
    • M/L/XL = 31 in to 40 in (78 cm to 102 cm)

    2) How do I adjust my FITLY?

      It is worth spending 30 seconds to properly adjust FITLY to your body shape.  If the thoracic belt is too loose, the retraction force of the elastic band will be weaker, and items may shift.  Too tight and you may feel uneasy. Position the thoracic belt 2 inches below your pectoral muscle / band line. 

      Tip: it should feel snug, not tight.


      3) IMPORTANT: maintain your zippers?

      You go through a lot when you run.  Your zippers too!  With proper maintenance, they’ll perform for decades. Without, they may lock up.  Read the blog that explains how to care for your zippers.  You’ll be thankful you did!


      4) How do I wash my FITLY?

      Wash with mild soap. Rinse with lukewarm water. Many runners take FITLY with them in the shower post workout, rinse and hang upside down top dry.  Do not use your washing machine, it will rub the water-resistant coating off.  Insert some paper towel in the pockets to speed the drying process up if you need to. 

      5) How does the hydration system work in Sub90?

      Sub90 comes with a FLASK500. Suction creates a vacuum pulling the liquid out, not gravity. Having a tight seal is important.  Make sure the attachment to the flask is tightly fastened.  If not properly screwed on, air can seep through and you won't be able to drink the whole volume. Use natural oil on the flask’s thread and screw cap to increase the seal.  The mouthpiece at the end of the tube has a liquid flow stopper.  Twist to open or simply pull.

      Tip: Dry your FLASK500 upside down. Insert a wooden spoon (or similar object) to enable air circulation inside the flask.

      6) I try to drink and nothing comes out, what am I doing wrong?

      Your flow stop is probably on, preventing the liquid to pass through. Please watch this quick video explaining what to do: FLOW STOP

      Also, if you insert the tube too far inside the flask, the TPU can start blocking the flow.  Make sure you only leave 1/2 in /2 cm max inside the flask.  

      7) Where can I store which flasks?

      -FLASK150 fits in the front pockets of all FITLY, except the Sub90 XS-S when filled completely.

      -Both FLASK250 and FLASK400 fit in the back pockets of any FITLY.  

      -FLASK500 comes with every Sub90 and fits right in the custom made thermo-pocket. FLASK500 does not fit the Sub45.

      8) The water in the flask seems to have a taste, how do I get rid of it?

      Fill your flask with water and add some baking soda to give it a good clean. Rinse multiple times. You will have completely removed any particle that can influence taste.

      Then, add a squeeze of lemon for the first several runs until you no longer feel a taste.

      Note: TPU material has been used in millions of products for decades.  In lab test, no particle transfer has been found in the liquid after 5 hour at 50°C/122°F.

      9) Technical Overview 


      Find the right band size