We started a small workout series on our channel! Its the first time weve used custom thumbnails as well as subscribe annotations. How does it work for you? How is the voice over? Any suggestions for improvement would be greatly appreciated.

The opening of the video reminds me of an ad that once played on YouTube. Some guy doing a self video in front of a car in his garage and he was selling a book?

Anyway, I would suggest cutting the video a little closer to when you finish speaking so there is no long pause. We don't really need to see you finish the full exercise, you can use a special transition (fade,push,pull,etc.) to the next workout.

Put some music in the background, brand your video thumbnail, make an outro card.

Show your uploading schedule on about page and banner, do you upload daily, weekly, monthly?
Maybe be more enthusiastic, I am not really into exercise but this is pretty good! Maybe il watch the series as it progresses! I could never do any of these.. . Well goodluck with the channel! Il going to subscribe to help out!