Neil:
Great to hear you've started Qigong . The benefits accummulate with time, and it only gets better. You'll enjoy it and benefit a whole lot in the bargain.
Yes, most of the exercises might be somewhat difficult at first. Especially, depending upon your prior level of physical activity and physical fitness. Go slowly and do what you can. You'll improve with time, and your stamina will inprove, as will your ability to move into and maintain the exercises. We all went through this, to some extent, but became more proficient with regular practice. If all you can do at this time is 7 minutes, that is just fine: work with what you have.
However, remember to wear a smile, relax, breathe, enter the silence, call upon your master, and by all means enjoy! The rest will take care of itself. This is a life long practice, don't rush it: daily, little by little, consistently, and more and more as it is possible for you, and this is the making of a possible, future adept - in TIME.
I assume you are speaking with respect to Spring Forest Qigong (SFG). I'm not sure which exercise you are referring to as the "standing on Stake" exercise? Maybe, this is a typo. Please, check if this is the correct name for the exercise? I'll be happy to share further, when I know which exercise you're referring to.
Enjoy your practice, just where you are NOW!
Much Love ....
