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Treadmill Workouts: PT Reviews 12-3-30 & 10-2-20

Treadmill Workouts: PT Reviews 12-3-30 & 10-2-20
Nerissa Shea
Level 4 Personal Trainer & Sport and Exercise Psychologist2 months ago
View Nerissa Shea's profile

First and foremost, it’s vital to point out there’s no magic workout or magic nutrition plan for fat loss. With all the misinformation out there these days, as a Personal Trainer and EIQ qualified Nutritionist, I’m obliged to highlight the reason why any diet and exercise program works for fat loss is because you’re in a calorie deficit. But let's take a look at the 12-3-30 workout and variations for weight loss.

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12-3-30 workout

Energy balance 101

Calories in (Food & Drink) vs. calories out (Basal Metabolic Rate, Thermic Effect of Food, Non-exercise Activity Thermogenesis & Exercise Activity Thermogenesis)

That aside, I’m always open to experimenting new ways in which to get people moving a little bit more so I was curious to try this workout. It's so important you find new routines which keep you active and interested in exercise. It’s too easy to become sedentary in day-to-day life. Food is delivered at the touch of a button and e-scooters spare people gruelling five-minute walks — so regimes which keep you motivated to move need to be celebrated.

The importance of training in the gym is often overemphasised and can disregard the importance of daily activity outside of training. In general, the goal of a workout shouldn’t be to ‘burn as many calories as you can’. The goal of training should be to strengthen/build muscle, and you can’t judge the efficacy of a workout on sweat levels, or calories burned alone.

If you want to focus on calorie burn, you can achieve that outside of the gym by increasing your overall activity. You may burn more calories in your 20-minute cardio/HIIT workout but to get more lean muscle into that beautiful body of yours – resistance training & progressive overload.

So, onto my personal review of the 12-3-30 workout.

The 12-3-30 workout was made famous by social media star Lauren Giraldo.

It’s a very simple workout that entails:
  1. Warm-up with a brisk walk for five minutes
  2. Turn the gradient on the treadmill to 12%
  3. Turn the speed to 3 mph (4.8km)
  4. Walk for 30 minutes
  5. Cool down with five minutes walking on the treadmill at 0% gradient

All you need is a treadmill and a decent set of trainers. A good podcast or Netflix show is also recommended.

It’s worth noting that as someone who absolutely destroyed themselves on the treadmill when I was younger, I was a bit apprehensive about trying a workout that entailed taking me away from my beloved weights section and back to the running machines. I’m a professional Irish Dancer and my idea of #Fitness up until the age of 25 was hours of cardio and as little food as I could survive on at the time. So of course, #Health? Right?

I used to force myself to run on the treadmill every single day for 45 minutes and then go off to football training, dancing class, whatever else I was up to when I was younger. So needless to say, I was a bit scarred by the treadmill. Then I discovered weight training and for me, and most of my clients, this is the most effective way to build muscle and in turn, become stronger and leaner.

All that aside, I was open to trying something new and the fact it does not involve running was a big plus for me. I also think it’s a great idea for this time of year when people are finding it more and more difficult to get out for a walk due to the shorter days.

If you’re completely new to training, it’s recommended that you start at a smaller gradient and perhaps a slower pace and eventually build up to the 12% gradient at 3mph. You can also build up to the 30 minutes.

12-3-30 workout

What did I think of the 12-3-30 workout?

Honestly, I had a lecture to catch up on, if I didn’t, I would have been extremely bored. You’re essentially walking on a treadmill for 30 minutes at an incline, there’s nothing too unconventional about this. Did I sweat a bit? Sure. But as stated above, more sweat does not equal a better workout.

This type of workout is something that you could add in as an extra ‘cardio day’ throughout the week in between your resistance training sessions for sure, if you enjoy it. Sure, you are ‘burning more calories’ having the treadmill set at a constant incline, but if you’re bored doing this workout, there are other, options.

Building/maintaining muscle is not just for the bodybuilders, it’s key for people at any age to be consuming adequate protein and incorporating some sort of resistance training into their weekly schedules.

Who is the 12-3-30 workout good for?


It’s a very accessible workout that anyone, at any fitness level can attempt. Because it’s walking and not running, it’s quite low impact, so it’s a lot easier on the joints. Even if someone couldn’t complete the 3mph at 12% gradient for 30 minutes straight away, they can build up to it.

And if it’s raining or dark outside and someone can pop on Netflix and incorporate this workout into their routine, then absolutely go for it, any extra activity is commended these days.

However, in my opinion, if you have 3 x 45 minutes to spare in your week to go to the gym, I highly recommend going and lifting some weights and if this terrifies the life out of you, hire a coach

Alternatively, buy some weights and train at home, that’s what a lot of my clients do. Some of them first came to me with resistance bands and now they nearly have full gyms in their sheds outside, they love lifting weights. They find it empowering as hell. They get such a buzz out of lifting! I’m yet to meet anyone who’s told me they haven't been super empowered watching their strength grow. It’s one of the best decisions I ever made in my life and my only regret is that I didn’t start sooner.

10-2-20 workout

Another treadmill workout is the 10-2-20 workout. Same concept, different treadmill setting. This one is a great option if you’re just starting out in the gym and just want to get moving. It’s lower intensity that 12-3-30 and only takes up 20 minutes of your time, making it a great little add-on to the start or end of a weights session.

If you’ve got a spare 20 mins, give the 10-2-20 workout a try.

  • Incline: 10%
  • Speed: 2mph (3.2 kmph)
  • 20 minutes

Take home message

I’ll always advocate for finding a way of moving that feels good to you. Whether that be lifting weights, going for a run, walking on the treadmill or a mix of it all. 12-3-30 and 10-2-20 are both great ways of adding a bit of extra movement into your week.

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Our articles should be used for informational and educational purposes only and are not intended to be taken as medical advice. If you're concerned, consult a health professional before taking dietary supplements or introducing any major changes to your diet.

Nerissa Shea
Level 4 Personal Trainer & Sport and Exercise Psychologist
View Nerissa Shea's profile
Nerissa has a Master’s Degree in Applied Sport & Exercise Psychology & a Bachelor of Arts in Irish Music & Dance along with her EQF Level 4 Personal Trainer Diploma, 200 Hour Yoga Teacher Training Certificate, Reiki Level 1 & 2 Certificate & is EIQ Nutrition Certified. After a successful competitive career in Irish Dance, claiming seven All-Ireland & International Champion Titles, she then went on to work as a Professional Irish Dancer traveling around the world with an array of prestigious dance shows. She believes in a holistic approach to fitness & mindset, encompassing mind, body & soul. She recently devised a method which she uses in her coaching entitled: The ESP Method ™ Empowered Mind: Master Your Mindset Strong Body: Strengthen & Nourish Your Body Powerful Soul: Ignite Your Soul Since launching her business in 2021, she has successfully coached hundreds of women to not only sculpt their bodies & reshape their mindset, but to change their lives. Her goal is through her content & guidance, people can gain inspiration, motivation & knowledge which enables them to make positive changes in their daily lives. Links: Website: I’m in the process of doing some re-jigging on this so can I send this on when I have the new one up & running? LinkedIn: Instagram: