Hi 1exception,
Thanks for writing and welcome to the alli message boards. You can post your health and fitness questions/concerns, suggestions, ideas or share your experiences here or post them on the "ask a specialist" forum and click on the health and fitness specialist.
To answer your question, it is perfectly fine to break up your exercise routine into 2 or even 3 separate sessions, instead of performing 1 continuous bout! There are many studies out there that have shown that intermittent exercise provides heart-healthy benefits as well as accumulates a great caloric expenditure! There are many people who either cannot physically perform a long bout of exercise or that do not have the time to during the day. By breaking it up into shorter sessions throughout the course of 1 day, they are able to achieve the benefits!
I would also encourage you to try to increase the intensity of your workouts if you're going to keep them shorter. By doing so, you'll increase the caloric expenditure of the exercise session and also challenge your heart and muscles to adapt to new and higher fitness levels!
Keep up the great work and stay consistent! With the help of alli, a healthy low-fat diet and regular, structured exercise you should see positive results!
Your friend in fitness,
Kelli