Ok.....so obviously you are playing around with me....8.5"....I think the guy in the video advocated for 10 feet.....I've got a Sierra Strap. I suppose I could measure that. Not 30', but it has some significant length.
I've got Baley's book. Can't recall exactly what he recommended. Thinking like 15'?
I have Baley's book as well. It's really good, has chapters on towel isometrics, doorway isometrics, and barbell exercises. I also have a strap from Strapworks, made according to Baley's specifications:
Double D-Ring Strap w/ 2 inch Flat Nylon Webbing [Choose Your 2" FNW Color:Forest Green] [Choose Your FNW Strap Length..:18'] [Choose Your 2" D-Ring:Heavywire] [Choose Your Metal Hardware Color:Uncolored] 1 $16.95 Shipping Cost: $4.99 Grand Total: $21.94 (2017 prices)
I use my cardio step as a platform and workout gloves are necessary for maximum grip, the seatbelt like nylon can be rough going.
I did this workout awhile back. I found the best way to record a workout is to send an email to myself.
Set 1 (with the Baley isostrap), 16 second holds at 3 positions (super fast change in position for all of these, thanks to the D-rings) Arm curls Military press Straight leg deadlifts Bench press Bent over rows
Had to stop and rest.
Set 2 Isometic Clean using the Sierra Exercise Isometric Strap, 16 second holds for 12 loops Squat at greater than 90 angle (a squat where the glutes are between the knees and ankles), 16 seconds. I use a jumbo carabiner with the Isostrap for this, or the Baley isostrap (I got the exercise from his book). The jumbo carabiner is the safer approach for this, I think.
Slackline is a good alternative. It is more comfortable on the hands than the webbing I have found. People are selling them all the time of Craiglist and Facebook. I got a 40' one for $15. You just have to tie a couple "O" rings to the sown loop end and you have an adjustable belt.
I usually just use a piece of 1" webbing for ISOs and it works fine. But if you are doing high intensity ISOs with the strap pulling against your torso a 1" piece might be uncomfortable.
I might have take my slackline and V2 out of mothballs just for old times sake.
Too bad the World Fit Iso-loop doesn't use more webbing to create larger loops . Eg, think isometric squats where the loop is placed over your shoulders . A standing isometric press also would require a large loop .