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It's the TikTok trend set to take over from 12-3-30.

The 25-7-2 workout is the next 12-3-30 workout. You heard it here first. In the same way that the 12-3-30 trend uses just one machine, so does the 25-7-2 workout: the Stairmaster, and while it hasn’t reached the masses just yet, its accessibility and seemingly simple (don’t be fooled, little ones) nature tells me it will no doubt pick up.

What I will say, is I reckon plenty of you will agree that a Stairmaster machine can appear significantly more intimidating than the treadmill used in a 12-3-30 workout. I’m right there with you (I very rarely use a Stairmaster) but think of it this way: the reason walking on a treadmill seems so easy is because we walk every day, but most of us also climb stairs, too, which is all you’re really doing on a Stairmaster. Not quite as easy as walking, but you get the jist.

So, given its inclusive and straightforward structure (which I’ll come onto in detail in a moment), and with safety sign-off from PT Luke Worthington, I decided this one was also worthy of a challenge: one session every day for a week. Here’s what happened.

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It was founded by social media Queen @shutupcamilla, using the following format:

For the purpose of this feature and finding out whether it’s really worth you lot giving a go (thank me later), I decided to go one-up and do the workout every day - at my local David Lloyd gym - but definitely don’t try this at home.

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The thinking behind not holding on to the Stairmaster as you climb is, supposedly, to help you create core strength. Avid TikTokkers might know it as the ‘ab trick’, but Worthington says there’s no case for it. ‘The core has a role to stabilise the midsection against resistance, and transmits force between the upper and lower quadrants of the body. Going hands-free on a Stairmaster is absolutely not core training.

‘We also can’t ‘trick’ our bodies – the body simply reacts and adapts to the stimulus that we provide it.’ You heard the man.

Done safely (and not every day for a week, like me), there are certainly rewards to be reaped. Worthington says that as well as standard cardio benefits, the structure offers the following advantages:

In comparison to the 12-3-30 workout, it’s pretty similar, but it does have you ‘working against gravity a little more than a treadmill’ and has ‘far lower impact, so there is an argument that it could be more joint-friendly’.

The jury’s out on this one. The TikTok world seems to think so, but IMO, going without hands isn’t necessarily safe. There were several times I felt like I was about to fall and had to grab on, and this became more apparent as the week went on, I became more tired, and I guess, lost concentration a bit.

Worthington affirms that while Stairmasters are ‘as safe as machines tend to be’, ‘there are limitations to machines that have us move only in one direction (forwards) and long term, can create movement pattern problems of their own’. In other words, you’ll probably have weaker posterior muscles if you’re always going forwards, and vice versa.

On the topic of hands or no hands, Worthington and I are firmly in the same camp. ‘The handrail is there for a reason,’ he tells me. ‘Stairmasters are sometimes quite high off the ground, and there’s a risk of tripping or falling if you don’t use the rail. Social media seems to have a trend for coming up with weird and wonderful different (read: incorrect) uses of equipment. Like sit ups on a glute hamstring machine, or facing backwards on a hip adductor machine.’ Stick to the instructions.

Worthington confirms that it’s certainly accessible and ‘safe for most people, providing the equipment is used correctly’.

Using a Stairmaster requires both serious strength (from your lower body) and cardiovascular fitness at once, and to say I was blowing after every session is an understatement. Granted, running needs the same, but apparently the effort of climbing stairs calls upon a lot more. Makes sense TBF, I don’t exactly leap up the stairs at home.

‘This is because you’re working against gravity more than a treadmill, so there’s an added element of resistance,’ Worthington explains. ‘Equipment such as bikes and rowers are fully weight supported, but with a Stairmaster, you have to manage your own bodyweight against gravity.’ Go figure.

If you’re a regular WH’er, you’ve probably heard us harping on about the importance of ‘engaging’ your core, or ‘activating’ your glutes, but turns out I haven’t exactly been practicing what I preach. After day two, I realised my lower back was aching like a good’un. I could barely watch Netflix without having to reposition myself or stretch out, so I decided to scrap the no hands rule which helped no end (thankfully there was no injury for me, just some extreme pressure on the area).

Why was I suffering? The OG aches and pains were probably coming from lazy muscles (they were essentially kicking back and relaxing, rather than engaging), and by holding on again, I was taking some strain out of my lower back, but still not engaging or activating my glutes and core enough.

It’s easier said than done, we know. When it comes to your glutes, think about clenching them. As for your core, imagine you’re tensing in apprehension of someone hitting you, but don’t suck in.

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Roughly mid-way through day three’s workout, I realised I was practically slouching to one side. My butt was sticking out too, and I’m always reminding myself to tuck my tailbone under (something ingrained in me since my yoga teacher training), so this was a biggie for me.

This is all to be expected as you get tired, Worthington explains, but poor alignment can also pre-empt injury.

‘There are certain muscles we often refer to as ‘anti gravity’ muscles, specifically the hamstrings, adductors (inner thighs) and obliques (our sides), that are most active in keeping us upright,’ he tells me. ‘Maintaining alignment comes down to proportionately strengthening those – the key word being ‘proportionately’.’

He gives the analogy of putting up a tent. ‘We continually pull and tighten each of the guy ropes until we have the tent pole standing up straight. If we slackened them all, it would fall over. If we tightened one rope disproportionately to the others, it wouldn’t be straight, and if we just tightened everything as much as we could without paying attention to the bigger picture, eventually one of them might snap. In the human sense, that’s us getting injured.’ We need to strengthen all of our muscles, basically – don’t just focus on your glutes or your abs – everything works in tandem.

Team that base strength with day-to-day posture habits. Imagine someone pulling you up from your skull with a piece of string, tuck your tailbone under so that there isn’t so much of a curve in your lower back, and try to make sure your shoulders aren’t rounding forwards, without jutting your chest too far out. Keeping all of these things in check made the 25-7-2 workout a lot harder for me, which proves I was, ultimately, doing it wrong, and thus wouldn’t have seen any benefits.

Confession: I’m obsessed with measuring my heart rate. It’s measured on my fitness watch, and I find it truly fascinating to watch how it changes throughout the day. I pay particular attention during a workout, and was surprised to see that it stayed within the same range during each 25-7-2 workout that it does when I run, despite the fact I felt like I was going to keel over at any minute (rarely the case when running).

Worthington enlightens me: ‘Cardiovascularly, you would’ve been getting the same benefits, but it feels harder because of the resistance you get from climbing against gravity, meaning the localised muscles have to work harder.

‘But from a physiological perspective, there would be minimal difference, and the ‘best’ form of cardio, is always the one you’ll do consistently – whether that’s cycling, running, dancing or playing netball.

He’s a huge proponent of power walking: ‘It’s an accessible form of cardio for most people. I’d say that every client I’ve worked with for the last 15+ years has had it prescribed within their plan.’

If ever I’m in need of some headspace, I always prescribe myself a solid dose of exercise. It normally does the trick, but not once did I come away from a 25-7-2 workout feeling at ease. As always, this is entirely subjective and may not be the case for you, but the coordination and balance required (especially when not holding on) meant I couldn’t zone out like I usually do. I imagine this is something that would improve with time once I’d got used to the motion and technique, but for now, it’s safe to say I won’t be using a Stairmaster to help with stress. Sweat, on the other hand, is guaranteed.