DAY 3 DOUBLE UNDERS PROGRAM

Warmup: 

4 Rounds 

20-second High Bounces 

10-second Rest

then

1:00 Wrists Warm-up 

BPM Endurance Work

Begin with a couple of warm-up sets of single-unders, around 20 seconds each, The objective is to find your groove. Then,

3 sets
▶ Perform single-unders at 140 BPM. Keep going until your HR is in zone 4 or 5. That might be a long time. It is alright if you trip here and there, as long as you can keep going and keep up the BPM pace. Once your HR is in zone 5, stop.
▶ Rest and walk slowly trying to bring your breathing back to normal. Rest until your heart rate is back to zone 3.

NOTE 
Please make sure to track your times per set and write them in the comments below.

HR ALTERNATIVE 
If you don't have a Heart Rate Monitor then follow these guidelines. Zone 5 is when the perceived effort is: hard or very hard. As soon as it is getting hard to keep the pace stop. Start your next set only when your breathing has come back to "normal" levels and you feel ready.

Round times were :47, :47 and :49 seconds. I stopped each time, not so much due to an elevated heart rate as the burning in my arch and calves.