手作り! ソフトテニス練習機/Tennis ball machine

How do you use a rowing machine? Step 1) Adjust your foot placement using the plastic which is numbered I’m a size 6 and use number 3 Step 2) tighten the foot strap Step 3) reach for the handle keep your arms straight whilst you push your legs to extend them, then pull your arms towards you and extend them out then bend your knees again, so think legs, arms, arms, legs Step 4) posture is key for this exercise, keep your back tall imagine there’s a piece of string at the top of your head tuck tho