This is more of a "What I did while riding my USS Azub Max today" thinking about my soon to be delivered Cruzbike. If folks get extra propulsion from the arms engaging the handlebars then I could try this now. I did. I used my legs to push myself against the seat harder than usual and at the same time used my arms to push against the handlebars. Pretty quickly my speed increased a few mph and my heart rate went from a piddling 125 to over 140. Hmmm...nice! Prior to this my upper body exerted no force on the handlebars beyond steering, and pedal propulsion came solely from the legs without much pressure against the seat. I've ridden this way for years. I discovered I could modulate my effort (heart rate/speed) by modulating the force in my arms, legs, and pressure against the seat.
I saw my average speed over 35 miles increase from 13.5 to 14.2 even with a 10-25 mph SW wind (my nemesis). Average heart rate up from 128 to 138.
I can do this with my current ride while thinking about doing it with my Silvio. If the Gods of delivery smile on me, mabye late next week!