A 40 Minute Hotel Room Workout.

 Actually 60 minutes from rolling out of bed, to dressed for work.

 I hate running.  Even on an interesting parkway.  Running in airport hotel parking lot is self inflicted torture.  But exercise is a necessity.  When I was travelling a lot and working too many hours a day to fit in a decent walk I had to make do.  

 I adapted a gymnastics warm up and cool down plus a bit of the RCAF 10 minute workout, added 23 minutes of high intensity Aerobics I learned as a part of a study run by the Physiology Prof and gymnastics coach at Stanford Wes Ruff.  

 The gym team among others were volunteers to determine the optimum level of aerobics to maintain peak Cardiovascular health.  That study is the reason for the universal recommendation for 20 minutes of aerobics in any exercise program.  We were divided into groups with varying levels of time and intensity and monitored monthly on a EKG bicycle with a breathing mask.  (The worst part of the study.)  Intensity mattered less in maintenance of existing levels of CVH, if you could do it at all 20 minutes kept you where you were and more didn't help at all.  It didn't hurt of course, and strangely pushing the intensity didn't help either. You were stronger and had more endurance but the basic level of CVH didn't change (for the College Varsity level athletes in the study.)

In any event the workout:
Two minutes of limbering and stretching I use the usual six point strech, the first six limbering, the last full 30 second stretches.  
Two minutes 4 position Yoga position bicepts work
Thirty second supine planche,  feet on the floor now. 
Thirty second seated toe touch stretch
One minute supine bicycle ab work
Fifteen seconds of push ups, as hard as you can make them Chest slaps originally, lucky to stay off knees now. 
Back arches as needed for tone.  Too many may overpower core and cause back issues.  
Two minutes of back stretches (Pretzel) for back issues
One minute of crunches as hard as possible.

 That should put you at about 9 minutes for a minute breather and drink and "Exercise pulse rate." 

 Twenty three minutes (nominal) run in place intervals.  18 sets of a minute run + 20 sec .Jumping Jacks or sprint as able. I know that is 24 minutes but you can run and jump faster than that can't you? If you get much below 23 jack up the intensity. I count steps and jumps rather than watch a clock.

The clock comes at the end of the 23 minutes.  Hit the lap timer, find a Jugular pulse in ten seconds, and count 10 seconds X6  for your intense rate.  That was the study protocol which I have stayed with all these years to track a reliable baseline.  I assume modern gadgets are better but I can't be bothered.  

Cooldown 
30 Sec wide leg, straight foot wall stretch
One min. light exercise, I use a in place mogul run.
30 second each one leg stretch
30 sec each one leg knee bends, balance and mild exercise
30 sec wide leg, splay foot deep wall stretch to end.  

Another pulse check, S.S.S. and 20 minutes later a recovery pulse check (optional it doesn't change much except when you slack off for a while.)