Coach Caelum
CORE4 · 1-1 Coaching Programme

Hit your 90-day target or you don't pay a penny.

Most plans assume you have nothing else going on. CORE4 assumes you do. Four weekly levers, sessions that adapt around your week, and one coach in your corner.

CORE4 · 2026 1-1 PRIVATE
0+
Men coached
0-day
Money-back guarantee
24/7
App access
Caelum Girn, founder of CORE4
Caelum Girn · Founder
15 men  currently coaching
5 spots  left
L3  certified coach
−17.4 lb / −7.9 kg  avg fat lost

Hit your 90-day target, or you don't pay a penny.

§ 00 - Calculator

How much weight do you want to lose?

Input your current weight, target weight and weekly training commitment to see how demanding your 90-day target will be.

/ Your 90-day targetInput
Target check pendingInput your numbers to see how demanding your 90-day target will be.

Add your current weight, target weight and sessions per week. Your 90-day check unlocks here and lands with Caelum.

§ 01 - The System

The CORE4 framework. Four levers, every week.

Sessions that adapt around your week.

We pull the biggest levers and ignore the noise. Compound lifts, dialled-in rep schemes, recovery built into the calendar. Your training is built for the busiest week of your year, because that's the week most plans fall apart.

  • / ACustom programming reviewed every 7 days
  • / BForm check video reviews within 24h
  • / CHotel-room, garage and full-gym variants
  • / DPeriodised for travel, deload and life
§ 02 - The App

A coach in your pocket.

CORE4 coaching app dashboard showing daily check-in, next workout, goal and progress

Built around the essentials. Engineered for the chaos.

CORE4 runs through a single app. No spreadsheets, no lost WhatsApp threads. Daily check-ins take thirty seconds. Coach replies inside 1 hour. Your training, your macros, your sleep score and your direct line live in one place.

  • / 01
    Daily check-in
    Weight, sleep and steps in under 30 seconds. Photos once a week.
  • / 02
    Direct line to coach
    Voice notes and DMs. Replies inside 1 hour.
  • / 03
    Adaptive plans
    Training and macros shift weekly based on your progress.
  • / 04
    Travel & restaurant mode
    Hotel-room sessions and a restaurant playbook for client dinners and travel weeks.
§ 03 - Results

150+ men. Lives as busy as yours.

Real clients, real schedules, real check-ins.

Josh, before CORE4Josh, after CORE4
Josh
Restaurant owner · 32
−86lb / −39 kg
Diabetes risk reversed
Tom, before CORE4Tom, after CORE4
Tom
Firefighter · 28
−50lb / −23 kg
Firefighter transformation
Mavneet, before CORE4Mavneet, after CORE4
Mavneet
Accountant · 29
−13lb / −6 kg
Conditioned for the corporate arena
Sundeep, before CORE4Sundeep, after CORE4
Sundeep
Architectural designer · 31
+13lb / +6 kg
8 week wedding transformation
Harry, before and after CORE4
Harry
Dental practice owner · 45
−63lb / −29 kg
Practice owner transformation
Kray, before CORE4Kray, after CORE4
Kray
Chef & restaurant owner · 34
−56lb / −25 kg
Restaurant owner transformation

Hit your 90-day target, or you don't pay a penny.

§ 04 - Trajectory

What ninety days looks like.

CORE4 / Standard Programme
CC · Standard Track · 2026
TARGET OR REFUNDED 90D WINDOW
P-01 · ONBOARDP-02 · ACCLIMATEP-03 · COMPOUND0255075100T-0T+7DT+30DT+90DBaseline setOn trackTarget
P-01P-02P-030255075100T-0T+30DT+90DBaseline setOn trackTarget
/ 01 of 04Onboard
day 00

Diagnostic call, app setup, first workout in 48h. No guesswork.

to first session48h
/ 02 of 04Acclimate
week 01

We get into the plan, read your current stats, and optimise from real data instead of random numbers.

from real dataBaseline set
/ 03 of 04Compound
month 01

Macros tuned, baseline strength up 8 to 12%, energy back. Pattern is locked.

month-1On track
/ 04 of 04Result
day 90

Target hit, four lifts up, a routine that survives the worst week.

hit or refundedTarget
§ 05 - A Sample Week

Sessions that adapt around your week.

2.8htraining
3strength sessions
6.5hmoving
56hsleep window
7 / 7check-ins
MON · 01
TUE · 02
WED · 03
THU · 04
FRI · 05
SAT · 06
SUN · 07
Train
PUSH
50 min
Easy cardio
30 min
PULL
55 min
-
LEGS
60 min
Hike
90 min
-
Fuel
1850 cal
3 meals
1850 cal
3 meals
1850 cal
3 meals
Client dinner
Restaurant plan
1850 cal
3 meals
Refeed +400
Family meal
1850 cal
3 meals
Move
10k steps
Walk + call
Stretch
10 min
10k steps
Walk + call
12k steps
Walk + call
Sauna
20 min
Outdoors
Hike or kickabout
Easy walk
30 min
Recover
7.5h
Sleep
8.5h
Sleep
7.5h
Sleep before 11
6.5h
Late night
7.5h
Sleep
8h+
Lie-in OK
9h
Full reset
Check-in
Logged
30 sec
Logged
30 sec
Logged
30 sec
Logged
30 sec
Logged
30 sec
Logged
30 sec
Coach call
Progress review
§ 06 - Your Coach

Meet Caelum.

Caelum Girn, founder of CORE4

I built CORE4 because I couldn't find a coach who took my schedule seriously. Every programme I tried assumed I had two hours to lift and three to cook. Most of my clients have neither.

I grew up skinny and got bullied quite a lot. I started working out at 15 and found this was the first time I was actually good at something. After years on the gym floor as an in-person PT, I went online because the math is obvious: a coach embedded in your week beats a coach you see for an hour, every time.

Since 2024 I've coached over 150 men through CORE4. Tech founders, surgeons, agency owners, dads. The pattern is always the same: they don't need more information. They need a system that adapts around their life, not one that overturns it.

Caelum Girn
0+
Clients coached
0yr
Training experience
L3
Sport & Exercise Science cert.
§ 07 - Why CORE4

Why this makes sense for you.

In-person PT
Online template
On your own
Coach access
1 hr · 1 to 2× wk
Group call · monthly
-
Time in the gym
5+ h / week
4 to 6 h / week
Whatever sticks
Estimated time to result
36 weeks
52 weeks
No defined timeline
Custom plans
Adapts to travel
Nutrition strategy
Result guarantee
None
None
None
§ 08 - Investment

The programs for men who are too busy for an average fitness plan.

Tier 01
14 Day Kickstart

A 14 day challenge to get wins under your belt with your fitness and prove that even when you are busy running a business, the right system still lets you get in shape alongside it.

Free
14 day challenge
  • A 14 day taste of the CORE4 system
  • Daily habit targets
  • Fast wins with training and nutrition
  • No card, no catch
Tier 02
CORE4 Brotherhood

For men who do not want or need a 1:1 coach, but still want to be surrounded by like-minded people on the same journey. We are the product of the people we surround ourselves with.

$50
per month
  • Group training & nutrition frameworks
  • Weekly group check-ins
  • Like-minded men on the same path
  • Cancel any time
§ 09 - In Their Words

What clients say.

"I genuinely couldn't believe how easy it was to get in the shape I'd dreamt about for years. I thought extreme diets and cardio were the way. Turns out I couldn't have been more wrong."
Sundeep
+13 lb / +6 kg muscle · 8 weeks
"I'm so glad I took the jump and switched to online training. My in-person PT was great. I just didn't realise how much faster I'd see progress with a coach in my pocket every day."
Richard
−29 lb / −13 kg · 6 months
"I'd tried tonnes of fitness plans in the past. I'm glad I tried one more time. Caelum wasn't lying when he said this is the last plan I'd ever pay for."
Luis
Transformed at 51
§ 10 - The Guarantee

Hit your 90-day target. Or you don't pay a penny.

Lose 15lbs, get abs, or hit whatever challenge you set yourself. I'm so confident I'll get you there that if you follow the system and miss the mark, I'll give you all of your money back. You're paying for results, not a helping hand.

§ 11 - FAQ

Common questions. Straight answers.

Yes. The system adapts around travel, restaurants and unpredictable weeks, which is why I can stand behind the guarantee. If you follow the plan, log the check-ins and do the work, your schedule is not the reason you miss your target.
No. The first fortnight is built to create momentum from wherever you are now. I am not guaranteeing results because you are already fit; I am guaranteeing them because the system gives you clear steps and adapts as your body responds.
Because results happen across the full week, not just inside a gym slot. Online means daily check-ins, food and form review, and adjustments when your week changes. That gives me enough visibility to be confident about the guarantee.
You get a full refund. The guarantee is there to put your mind at ease because I know that if you follow the system, log your check-ins, complete your sessions and track your food, you will achieve the target we agree.
Usually three focused training sessions, short daily check-ins and the weekly optimisation needed to keep the plan moving. It is designed to be realistic enough that you can follow it, because the guarantee only works when the system fits your life.
No. Busy is the point. CORE4 is built around sessions that adapt to your week, nutrition that works around client dinners, and check-ins that take less than a minute. The guarantee is my way of saying the system can work even when life is full.
You do not have to take it on faith. I am confident enough in the system to put the money-back guarantee behind it. Follow the plan, do the work, and if you still miss the agreed target, you get your money back.
Mostly. The system was built for busy men with a job, a family or a calendar that does not leave many spare hours. Outside that window I'll still take a discovery call, and if we're not a fit I'll point you to someone who is.
§ 12 - Apply

Apply for CORE4.

  1. 01Fill in the application, then choose your call time without leaving this page.
  2. 02I'll review your application and confirm the call if I think the program will help you.
  3. 03We use the call to decide whether CORE4 is right and get your custom plans in the pipeline.
<1h
Reply target
5
Spots open
24/7
App access

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