The Ham Sandwich features sweet spot over/unders, with 30/30s "sandwiched" in between. The over/under intervals are alternate between 2 minutes Z3 (88%) and 30 seconds Z5 (110%). The 30/30s up the ante a bit and alternate between 30 seconds Z6 (130%) and 30 seconds Z1 (50%). Yes, there are rest breaks, but they are purposely short to keep the heart rate and metabolic demands up, and I dislike rest (kidding!) Better eat your sandwich quick before the bread gets soggy...