Based on the information given. You have a few goals you are looking to accomplish with a new routine. 1. You want to lose 20-30lbs and 2. You want a less time consuming routine.
We also see that you like to do Interval training and probably have a pretty good anaerobic work capacity. You also seem to enjoy core work.
This is not an ordinary routine and not something I recommend to a lot of people, but you might find Charles Staley’s EDT (escalating density training) a different way to change things up, meet your goals, and something that you might suit you based on what you stated in your post.
You would do two pairs of exercises and use your 10 rep max weight in each exercise. Try to pick exercises that you will be able to go back and forth to seamlessly such as using a similar weight barbell, bodyweight exercises, or similar weight dumbells. Or, if you have a power rack and can tie up two barbells if needed, you can expand the selection.
The following routine would be done 3 or 4 times per week with a day off in between.
You can pair the exercises the way you want but I would probably pair a push and pull for the first pair and a lower body and ab exercise for the second pair.
Perhaps something like a DB Bench press/DB row for pair 1 and step ups / cable crunches for the second pair. Make up three workouts so that you do not repeat until the following week.
What you are going to do is alternate between the exercises in each pair doing the same number of reps, start off doing 6 or 7 reps of exercise 1 then 6 or 7 reps of exercise 2. When you can no longer complete 6 reps drop to 5 then 4, etc. You are going to keep rotating between the two exercises for 15 minutes (keep track of the total number of reps which will be the same for each exercise. Since you are using your 10RM for both, they should be equally challenging). At the end of the 15 minutes, your total reps is your
PR (personal record) zone. Rest between exercises and sets is up to you. Take as much time or as little time as you need. Repeat for the second pair of exercises.
Next week, you will do the same exercises using the same weight but you are going to try to beat your previous
PR Zone. When you can increase the total reps in the pair by 20% over the first workout, you can increase weight.
This will give you a total body workout, that will fire up that heart rate, and challenge every muscle in your body and your anaerobic work capacity to its max. It should be a great workout for someone looking to burn fat and it also guarantees that you are done in 30 minutes.
You can add some cardio in at the end of the workout or on the off days.
It’s different and may not be something that you’d be interested in trying, but throwing it out there.
I should add that you will be doing a good number of reps and will be fatigued by the end of each 15 minute block, so choose exercises carefully. Exercises that place a good deal of stress on the spine may not be the best choices if you tend to loose good form when fatigued. After all, keeping you healthy is always the #1 goal.