I Rated the Top Three TikTok 4-2-1 Workout Routines

Credit: TikTok

Your workout routine doesn't need a fancy name like "CrossFit" anymore—now we can just string numbers together and call them workouts? I kid...mostly. Because today I’m considering the 4-2-1 workout trend that’s all over TikTok (and other places).

As 4-2-1 is less a workout and more a vague set of rules, I can’t give it an overall “good” or “bad” grade, but I can rate some of the different ones going around, and also explain the overall pattern of a 4-2-1 routine. But first, let’s define our terms.

What is a 4-2-1 workout? 

Well, it’s actually not a workout. It’s a routine. And it’s not even a routine, it’s a vague structure for a routine. To put it another way, the 4-2-1 is a split. 

A split simply refers to the way you split up your workouts for the week. In this case, 4-2-1 means: 

4 days of strength training

2 days of cardio

1 day of rest or, depending on who you ask, one day of mobility work.

That’s what people usually mean by 4-2-1, but I'll talk about some variations on this theme in a minute. 

Is 4-2-1 the best way to split up your routine? 

It’s important to remember that a split is just a method of organization. Asking if 4-2-1 is a good workout routine is like asking if “breakfast, lunch, dinner” is a good diet. You can’t answer that question until you find out what the diet (or routine) contains. 

But I will say that, like “breakfast, lunch, dinner,” the 4-2-1 split is a great structure to build on if your priority is building strength. On the other hand, if your focus is cardio (say, you’re a runner), you might want to flip that around and do four days of cardio and two days of strength training. 

What does a 4-day strength training split look like? 

Within the 4 strength days, you still have a lot of options for how to split up your training. Here are some of the best 4-day strength splits: 

Upper/lower split

Probably the most common way 4-day strength split is this one:

Upper body

Lower body

(rest or cardio here)

Upper body

Lower body

This way, you never work the same muscle group two days in a row. That allows you to go a bit harder in each workout than if you were using the same muscle group back-to-back. 

4-day full body split

Contrary to internet bro science, however, there is no hard-and-fast rule about how much rest you need between workouts. The 23 hours or so between Monday morning and Tuesday morning are plenty of time to recover, if you want or need to work the same muscle in both workouts. With that in mind, you can try something like this: 

Full body (light) 

Full body (heavy)

(rest or cardio here)

Full body (light) 

Full body (heavy)

That’s exactly the split I’m on right now, in a program from my Olympic weightlifting coach. The “light” days feature competition lifts like snatches and jerks, and the “heavy” days are heavier strength lifts like deadlifts.

Mixed split with focus day

You could also do a combination of the above, with some body part days and some full body days. Something like this: 

Upper body

Lower body

(rest or cardio here)

Full body

Arms & shoulders

This variation hits most body parts twice: upper body on days 1 and 3, lower on days 2 and 3. And then on day 4 you give a little extra love to the body parts that you think might benefit from a third day. In our example here, that would be arms and shoulders, but that would also be a good place for a glute day if you’re trying to build a butt, or a strength/skill day if you’re trying to work on something tricky like handstands, or even a different focus for that day each week.

Let’s rate TikTokers’ 4-2-1 splits

I searched TikTok for “4-2-1 workout plan” and "4-2-1 workout routine," hoping to find a ton of examples of how people are doing this routine. Here are the top results, with my critiques.

Olivia Iannelli

Day 1: Lower body (video of back squat)

Day 2: Upper body and HIIT (video of bench press)

Day 3: Steady state cardio and mobility (video of treadmill running)

Day 4: Lower body (video of deadlift)

Day 5: Upper body & glutes (video of overhead press)

Day 6: HIIT cardio

Day 7: full rest

Does it fit the structure? Yep. That’s 4 strength days, 2 days dedicated to cardio (but a total of 3 days with some kind of cardio), one mobility day (combined with cardio) and one day of rest. That fits the bill, with the “1” day being that full rest day. 

Is it a good workout plan? I don’t know! She doesn’t say what she’s doing on those days, just gives a video clip of one rep of one exercise for each. The caption includes an ad for a workout app called Ladder (her username is @livfromladder, so that tracks). 

My verdict: This isn’t a workout plan, just an ad. 

Training Truths

This one is a dude in a ball cap giving us a 4-3-1 split. Not a typo, those are numbers that add up to eight.

4 days of cardio, 40 minutes a day, any cardio you want. This can be done on lifting days or non-lifting days.

Weights day 1: chest, shoulders, triceps (3 exercises per body part, 3 sets per exercise)

Weights day 2: back and biceps (same rules as above, you pick the lifts)

Weights day 2: quads, glutes, hamstrings

1 gram of protein per pound of your body weight, as lean proteins

He then gives an example of the exercises you might pick for each of the weight training days, and a list of protein sources. 

Does it fit the structure? Not the 4-2-1 we talked about, no. And rather than the numbers all referring to days of training and adding up to 7 (arguably the number of days in a week), two of the numbers are about days of training and one is a reminder to get your protein. 

Is it a good workout plan? It’s missing some things, but what’s here is not bad! The lifting split is a push/pull/legs split, which I would rather see as a 6-day instead of a 3-day routine (so that you can hit each muscle twice per week). That said, if you like this schedule and you make progress on it, there’s no reason for me to stop you. The structure of three exercises per body part, and three sets per exercise, is simple enough to remember and gives you some flexibility in picking exercises that you like and that you can do with the equipment that is available to you. I wish it said more about weights, reps, or progression, but certainly some part of the target audience will take this, run with it, and get good results. 

The 4 days of cardio are a nice addition. A lot of people following this bro-ish kind of workout structure might try to skimp on the cardio. But 4x40 minutes is 160 minutes per week, which neatly fits the 150 minute requirement for general health. I like it. 

One gram of protein per pound of bodyweight is overkill, but it’s stuck in everyone’s minds because it’s easy to remember, and I suppose there’s some value to this. You also don’t need to stick to lean proteins; fats are good to have in your diet as well. 

My verdict: If this appeals to you, I say go with it. The cardio and weights days will benefit your health, and if you do your best to challenge yourself on the weights days, you’ll make some progress in strength. I’d ditch the nutrition guidelines as long as you get a reasonable amount of protein in your diet.

Dr. Robin B

I kept seeing this account in the search results for 4-2-1 workouts, but each video was just the creator doing a compound dumbbell move (like a squat, clean, and press, or a lunge and curl) with promises that 4-2-1 dumbbell combo moves will snatch your waist and help you lose 10 pounds!

Does it fit the structure? Hard to say, but she’s doing the moves with light weights at a fast pace, so this isn’t likely to work well as strength training. She says you “just” need a pair of dumbbells, so I suspect there may not be any heavier work in the mix. 

Is it a good workout plan? Sigh. It’s another Ladder ad.

My verdict: Most of the 4-2-1 videos out there seem to be ads for workout apps.