5, 10, 20 - The Starter Pack for the "Mature Beginner"
Off the top of my head and going back through some old notes, the 5, 10, 20 idea is one of these old things I'd thought of (but let's face it, probably very un-original) for the "mature-beginner" to guide themselves by in the weight room. Just like 3 sets of 10 is the tried and true, all-time understanding of what we do with weights, or get started with weights, the 5, 10, 20 protocol is what we do when we "lift" and, to me, is something that might just be a more sustainable option with a longer improvement curve over time.
In case you don't know - 3 sets of 10 is probably where everyone starts as everything works well when we start. So long as you're not hurting yourself, anything you do in a weight room when you first start will work reasonably well, so 3 sets of 10 is the real starter pack, really. It's simple, memorable and effective. But, I'd argue - it's shelf-life might be not so long, as we do physiologically adapt to these things as well as the novelty of 3 x 10 becoming somewhat stale psychologically. By the time one is displaying both the physiological adaptation and staleness of 3 x 10, then we're probably starting to deplete the "low hanging fruit" benefits of that method, the easy wins. This is what I call the "mature-beginner" - no longer on the steepest part of the novice learning curve, but still got some novice gains on the table. This is where some minor tweaking can make that curve extend out and the easy wins can keep coming along reasonably okay.
Start 5, 10, 20.
All it is is doing a couple of exercises for sets of 5's, then doing a couple exercises for sets of 10's, then doing a couple of exercises for sets of 20's. I'll elaborate...
If you were doing a full body strength routine, choose 2 "big lifts" or major exercises, one upper body focus and the other lower body focus. Easy example - Bench Press and Leg Press. Simple and by the time you reach "mature-beginner" phase, you ought to know how these work. These will be your exercises that you do sets of 5 with.
Next, choose a couple more exercises - upper focus and lower focus and preferably multi-joint exercises and that work different muscle groups or are somewhat different than your main lifts from before. Example from above would be to do a Seated Row (opposing the bench press) and a Lunge variation for sets of 10.
After this, same deal again - choose another couple of exercises but this time we'll make them "smaller" exercises that work mainly a single muscle at a time. Again, upper / lower focus - things like a bicep curl and a hamstring curl and do these for sets of 20.
How this looks, in table form
Exercise Sets Repetitions Rest (between sets)
Bench Press 3 5 2-3min
Leg Press 3 5 2-3min
Seated Row 3 10 1-2min
Lunge 3 10 1-2min
Bicep Curl 3 20 1min
Hamstring Curl 3 20 1min
The rationale for changing up the rep scheme from the universal 10's across the board is that by the time you reach the "mature-beginner" phase of things, we need to start to modulate our effort into different movements and skills in order to keep progressing, as well as keep things interesting. In other words, some exercises work better when you're doing less but the intensity is higher, and some exercises work better when you do more but the intensity is lower. This is all very simplistic and it is nuanced, but for the case of providing "rules of thumb" for the uninterested newbie who just wants the rules, not the philosophies, this is all that's needed to know. Anyway, tweaking the rep ranges is like the auto-pilot that guides your effort for the exercises in a more suitable manner, if that makes sense. Basically, the amount of reps that is prescribed guides your effort / weight / intensity more appropriately than your instincts.
The biggest areas of self-regulation when it comes to the application of this template though is a couple of things that one needs to loosely get their head around, and if you're in the "mature-beginner" phase then we'll make the assumption that you're versed enough with these things.
Technique - I'd hope you're confident and adept enough at basic, free-weight lifts in the gym and executing the movements well enough.
Effort - Having some grasp of what working hard is and knowing the sweet spot between what's too hard and what's too easy.
Technique and effort are intricately linked, in that they kind of regulate each other. If you just absolutely cannot do an exercise with good technique for around about the amount of reps prescribed, then it's probably too heavy. If you can do a fair bit more than the amount of reps prescribed with faultless technique, it's probably too light. The prescribed reps of 5, 10 and 20 as mentioned before, is kind of meant to regulate the effort for you, but one still needs to be somewhat attentive as it's not always perfect. Getting too enthusiastic or over-estimating oneself is not un-common in the gym, so being aware of your own technique and how hard stuff is still matters and is important. Gauging and mastering this balancing act or "feel" for lifting is definitely a skill in itself and does take time to hone, so err on the side of caution and be conservative with how hard your hardest set of 5 or set of 10 reps is, just to play on the safer side till your instincts sharpen - which will take time.
All in all, with this template you're looking at 45-60 mins time investment - the standard advertised obligation to the gym when we all start and that is fine. There are a million different ways to skin a cat, as methods there are infinite but principles there are few, and if we wanted to dissect this or totally deconstruct it, come up with something different that might be better, then I'm not denying that that is totally out there - again, there are many ways to skin a cat. But this little template is about as idiot proof as I could come up with this afternoon, without getting too far in the weeds of every nuanced facet within the program. After all, this is directed at the "mature beginner" who doesn't give much of a shit for the details...
5, 10, 20 - Just concoct your own menu of exercises, follow what it says the best you can, and honour it with 6 months of 2-3 x per week consistency.
See how you go