New workout schedule starting next week

Starting next week I’ll move to a 4 days/week workout schedule after following a 6 days/week schedule for almost a year and a half. The change comes because of quite a few reasons, but basically my workouts include 2 Pilates and 2 Yoga lessons which are nice to have but I don’t feel they’re such a necessity. I’m going to focus on aerobic and muscle training.

Writing this post down and noticing all the days in which I wrote “Rest” (see below) kind of scares me. I know that I’m still going to be just as fit as I am today, as I haven’t given up aerobics nor muscle workouts, but it’s still a big change.

Here’s the complete schedule:
Sunday: HIIT on an elliptical + 20 minute run at 85% MHR; Muscles: shoulders, biceps, upper-back.
Monday: HIIT on an elliptical + 20 minute run at 85% MHR; Muscles: chest, legs, triceps.
Tuesday: Rest.
Wednesday: HIIT on an elliptical + 20 minute run at 85% MHR; Muscles: shoulders, biceps, upper-back.
Thursday: HIIT on an elliptical + 20 minutes run at 85% MHR; Muscles: chest, legs, triceps.
Friday: Rest.
Saturday: Rest.

My HIIT workout is:
3 minutes warm-up
1 minute at 60% effort
1 minute at 70% effort
1 minute at 80% effort
1 minute at 90% effort
1 minute at 60% effort
1 minute at 70% effort
1 minute at 80% effort
1 minute at 90% effort
1 minute at 60% effort
1 minute at 70% effort
1 minute at 80% effort
1 minute at 90% effort
1 minute at 60% effort
1 minute at 70% effort
1 minute at 80% effort
1 minute at 90% effort
1 minute at 60% effort
1 minute at 70% effort
1 minute at 80% effort
1 minute at 100% effort
2 minutes cooldown
(total of 25 minutes)