Yes, you should be ready to run some intervals. You can do one interval workout of each discipline in a week and like RnR said, cluster them if you can. If you're not doing a lot of workouts you might want to do them on consecutive days, like tues run and wed bike. Save the long stuff for the weekend.
I cluster my week like this:
Mon: light swim and yoga/strength workout
Tues: hard run - intervals and med length bike at low intensity but not recovery (ie 20 to 60 min of solid zone 2)
Wed: hard/long swim and recovery bike
Thurs: hard hill ride, hitting zone 4 and 5, solid zone 2 run
Fri: recovery ride and light swim with short fast intervals for speed form
Sat: Long ride, run or brick
Sun: Long ride or run
The big thing to note is that I have my hard workouts 3 days in a row and I position easy days on either side of those to allow for adequate recovery. It is just as important to plan for recovery as it is to plan for intervals.
Hope this helps.
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