The 4 one minute sprints twice a week is not, that I know, of a recommended form of exercise. The researchers were interested in the minimum amount of exercise out of scientific curiosity.
As you can imagine they experimented with other schedules less than and greater than 4 min x 2 time per week. Blood sugar was under excellent control with the minimum stated.
Strength, flexibility, co-ordination, fat loss, etc. are other considerations: but they did demonstrate their hypothesis that you need to deplete energy from your muscles to make room to sop up glucose in the blood.
p.s., you can imagine the horror we will soon face on late night TV as an infomercial selling a cheap exercise bike promises you CONTROL DIABETES AND LOSE WEIGHT WITH 8 MINUTES EXERCISE A WEEK. NO MONEY DOWN, PAY IN 8 EASY INSTALLMENTS, IF YOU ORDER NOW YOU GET A FREE ABERCISER. ORDER NOW OPERATORS ARE STANDING BY
Yes. If you are addicted to caffeine, although a large amount of caffeine will keep you awake, a small amount can promote sleep.
Despite my claim to never drink tea or coffee after 4 p.m. I occasionally take a 1/4 cup of tea before bed if I need to get to sleep quickly because I'll be rising early.
This is in proportion to how much tea/coffee I drink during the day: 2 or rarely 3 cups. I've known 6 cup a day coffee drinkers to drink an entire cup of coffee before bed. (I've also known them to have anxiety, shaky hands, and logorrhea)
Much of the excitement we get out of our work is that we don't really know what we are doing. -- E. Dijkstra