This is the first of our challenges that has nothing to do with cardio and everything to do with yoga and balancing. Standing Bow Pulling Pose is one of my absolute favorite poses in yoga because it works so many parts of the body. This pose also improves balance, flexibility, and posture. The pose also helps tone all the muscles of the arms, legs, and core.
I would recommend adding this pose to the end of a yoga flow once you are already warmed up. To complete this for the time needed, you will need to look at one spot straight ahead, having the balancing foot locked, and keep a pull between the upper body and the held leg. This pulling action is what helps keep balance in the upper body where both the leg and the body are trying to be as tall as possible. A balance in this push-pull will create a balance in the pose.
The pulling arm should be held around the ankle or foot while the other arm can be straight ahead like above, or, lifted upwards in an ark. Really, the only way the non-holding arm can be is loose and floppsy down at your side. Just find a comfortable place for it and keep it there :)
I would also recommend trying to hold the 90-seconds the first time you get into this pose. It may not happen, but the more you try, the harder it will be since the body is reaching exhaustion. If this pose is new to you, try holding it for 1-minute first.
Good luck and let me know how long you were able to hold this for!