If you are serious about your training, you may want to invest in a sport watch. It has a weight of only 93 g, which makes it easy to wear.
Garmin fēnix® 6X Pro ONESIZE
Garmin fēnix 6X Pro, Ultimate Multisport GPS Watch, Black with Black Band
The product exists on 7 additional merchants that don't have an agreement with PriceRunner.
Too expensive? Get a notification as soon as the price drops.