Hi Pam! I saw your question on the "treadmill interval workout" about your Bowflex Treadclimber. I am 63 and had thought about purchasing such a machine for in home use.
However, I do have a "Y" membership and when I went there, I asked one of the ladies who man's the desk and helps people get acclimated to the machines if she knew about this Bowflex Treadclimber. She did. And I asked her what she thought about it. Her comment to me was that many people find it very hard on the knees and very hard to do, and that it is something that will take time to get use to doing.
That being said, I decided not to purchase the machine but to continue using the "Y" membership that I have.
I don't need to have issues with my knees because I am using the treadmill there and walking doing the incline and starting to do intervals. Although the fastest I can walk is 4 mph right now. I do not run nor jog. It's just too much on the knees.
I hope I'm posting this comment in the right place (I'm new). Concerning your question about the treadmill, if you are having trouble reaching 30 minutes then your heart rate may be too high. I don't know if you're familiar with heart rates and what yours should be. I keep mine at about 80% of my maximum heart rate but yours may need to be lower until you get used to the exercise you're doing. So you may need to reduce the intensity of your exercise to reach 30 minutes (that's what I would do). At the gym I go to there is no A/C and my heart rate soars. I just lower the speed and incline on the treadmill as needed. Here is the address to the American Heart Association to learn about heart rates. http://www.heart.org/HEARTORG/GettingHealt hy/PhysicalActivity/Target-Heart-Rates _UCM_434341_Article.jsp
By the way, I think 30 minutes is a really good goal. 1170 days ago