<human>: 28 yo F, runner since age 14. I think of myself as a runner, but I've only laced up and run maybe 3-4 times in the last 6 months. 
I used to run 35-40 miles/week and race 3-4 times per year. I used to be reasonably fast --full mar 4:16, half 1:55, 10K 0:50, 5K 21:02.
Now, I work a job I love, but that consumes my life. I'm a resident doctor (think "Scrubs"). My life is broken up into one-month long rotations, some require massive amounts of sleep deprivation and 80+ hrs/wk of work. I lack the reserve to continue to run during these times. Other months, I work a regular schedule and can reasonably run then. I have at least 5 years of medical training left that will require this kind of schedule. 
The problem with this is that I have zero stability in my running. I have to re-start my training every few months when work lightens up. This has led to more injuries (IT band, ankle sprains), poor running form and I haven't found time to race in the last 18 mos. Running helps me cope with the stress of my work, but when I need it most, I can't seem to find the time to run.

Summarize the given text in a few sentences.
<bot>: Help! What are your tips and tricks to keep running/prevent injuries despite a busy schedule? How can I keep my training on track with chronic sleep deprivation?