My Iron Cardio experience so far--
Short version: I like it a lot.
Details:
I (49M; priorities are health & longevity) started in October 2022. Other than a 7-day period (due to COVID) where I couldn't train at all, I've been doing it more-or-less continuously. (I have the PDF, not the video.)
What I like:
1. The IC sessions themselves have enough variety to prevent boredom. Yes, I've read all that stuff about how discipline is not boring, or how your muscles don't care if you're bored. But I got really bored on S&S, DFW, etc. For some reason, IC is different--even though it's the exact same 4 exercises (C,P,SQ,SN) each time! I think it's because of the variables (weight, time, rep schemes, etc.). Also, this sounds funny but for anything other than the basic 1 rep of each, there is a mental challenge--with traveling 2's or moving ladders you really have to concentrate so as not to lose your place. (Tip: Before each set, I say aloud what makes that set distinctive. E.g., "Two squats!" Then C,P,SQx2,SN.)
2. It plays well with other stuff. IC is deliberately not intended to be "do this and only this, and on exactly these days." The PDF discusses how to combine it with barbell, bodyweight, S&S, etc. I took some liberties here and extended this principle a bit. I do mainly IC, around 3-4 days a week. But I combine it with other stuff, based on my time available, how I'm feeling, etc. (See below for more on this.)
3. Because it's a fairly flexible/loose template, it's not really a huge problem to miss a day, or shorten a session compared to what you might have originally planned for that day, or lengthen one. I've found some other programs where you need to do exactly x, y, and z on Monday, Wednesday, and Friday to be too inflexible to deal with the vagaries of my life.
How I've done it
Warm-ups:
I'm 49 with a desk job, I train in the early morning, and my lower back is creaky when I first wake up, so I do a long warmup. Typically I do some mobility stuff on a yoga mat; then {30s of jumping jacks, 30s of hip hinges, 30s of air squats, 30s of standing T-spine rotations} x2, then 10min medium-pace on the rowing ergometer; then some light swings, cleans, presses, and rows with a 16kg.
The program:
When I'm doing IC, I try to do it as closely as possible to as described in the PDF. I vary all the parameters based on time available (e.g. a time crunch on a weekday morning may make a 20min session more likely than 40min), heart rate variability, soreness, etc. I've found moving ladders can be mentally hard to keep track of, and I know I've messed up the count on them several times, but in the end, does it really matter? I use Brett's advice that when you get 2 sets per minute, it's time to upgrade to a more challenging version.
On non-IC days, I rotate around the following:
a. About once every two weeks (never more than once per week), when I'm feeling awesome, I do an "intensity day" (insanity day?) where I do some weird challenge or timed AMRAP or HIIT or Tabata or something (with or without KBs) that's designed to leave me gasping and sweating. I think it's good to occasionally hit those high heart rates, and it satisfies any "itch" to be able to occasionally try something totally different.
b. Brett says in the book "this is not jogging." So I thought, what if I made something that was effectively the kb equivalent of jogging? So maybe once every two weeks, I'll use the heart rate monitor to do what I call "KB jogging" -- semi-random kb stuff for a block of time with the goal of keeping my HR continuously in the 125-135 range (Maffetone zone for me). This could include stretches of the IC moves, but not in the IC protocol, sometimes with a lighter weight so as to keep it continuous. I just constantly titrate to keep my HR in the zone.
c. Usually 1-2 days per week, I'll just walk on the treadmill in my basement (while watching TV). Depending on how I'm feeling, that could mean either in the Maffetone zone (with a steep incline), or lower but still doing some aerobic work (e.g. HR ~ 105-110), or when something is really off, just very low-key (3.0 mph, 0% incline) for pure recovery.
d. ~1 day/week, I do a slow-strength day. This could include TGUs, windmills, etc. I also use some machines at the gym these days to work muscles & angles I don't usually hit.
e. Some days, I can't make it to the gym, so I use my basement. I have an acceptable kb collection, but the ceiling is low so I can neither press nor snatch. So on those days, I replace the press with pushups (off the kbs), and eliminate the snatch. (I consider this a modified IC.)
E.g., over a 2-week span, I might do 6d Iron Cardio, 3d treadmill, 2d slow-strength, 1d "KB jogging," 1d intensity, and 1 just plain "off" day.
Finishers:
Most weekdays, I don't have time to do anything after the IC session. If it was a 20-min session, sometimes I'll do the IC swings finisher that Brett prescribes. On weekends, lately I've been trying the "Snatch Walking Protocol for Ultra-Athletes" as a finisher. I just take a ridiculously light kb to the indoor track at my gym and snatch-walk while people look at me funny.
How I've tracked progress:
Since my personal goal here is health & longevity (and the program is "Iron *Cardio*") I decided to use morning resting heart rate as my metric. As it happens, for some time I've been tracking my morning resting heart rate nearly every day, so I have data going back quite a while. On the day I bought the program (10/8/22), my RHR was 54. Today (1/10/23), it was 48. My lowest was 43 on 11/29/22. And remember, this is without any running or high-impact work.
So you can see that the conditioning is my primary focus and the strength is secondary. Someone else might do it exactly opposite. I know Mark Rippetoe says "A resting heart rate of 48 BPM is very cool, but it's not nearly as useful as a 405-pound deadlift," but I've got some family history with heart disease so my calculus is different. It's not that I don't want to be "strong first" so much as the muscle that I'm interested in training the most right now is my heart, and I'm content to let my clean, press, squat, and snatch improve at a slow pace as a secondary aspect of that work. It's quite possible I'm not using the program as Brett intended but this seems to be working well for me.
I don't think this would be a great program to build max/1RM strength & I don't think Brett markets it as such. I think my strength-endurance has improved somewhat -- I haven't tested this, but I suspect that, with the main weight I started off based on my 6RM, I could now get a lot more than 6. (I should probably test that - may do so later this week.) I also haven't done a before/after test of some performance-based conditioning measure (e.g. time for 1-mile run) but I've got to believe that the lower RHR pays off aerobically on stuff like that.
Conclusion:
I've run this now for 3 full months and it's the longest I've ever stuck to one program without getting bored. That's partly because it's not a "monogamous" program -- it encourages you to do other stuff on non-Iron Cardio days -- but also because it has enough variability within the IC template itself. On the key parameter I decided to track from the outset, RHR, I've seen an 11% improvement in 3 months, putting me in a range usually associated with joggers, cyclists, etc. It's enjoyable, produces measurable cardio benefits without joint impact, probably improves strength, and is compatible with doing a few days here and there of other things (be they other types of cardio, or more strength-focused). Endorse!