Ironman coaching
3,8km swim - 180km bike - 42,2km run
How do you prepare for that?
You have your reasons, your story.. you know why..
If you are anything like me back when I started training for my first Ironman in 2011, than you are not here to do an Ironman to look impressive, to hit a time or because you have nothing better to do with your time.
The Ironman is a metaphor for something more deep and meaningful. It is perhaps the biggest sports commitment you will make in a lifetime. A journey that will allow you to discover yourself. Be with yourself, show up for yourself and at the end, sure there is a finish line, but you.. You have changed.
The Body is strong, durable, fit and balanced. The Heart is alive, awake and energised. The Mind is calm, there is an inner peace, an unbeatable confidence and well-earned mental toughness. And the Soul is speaking, you have tuned in and have become an inspiration for the people around you.
Only you know why.. now let me help you to make it happen, because the path ain't easy.
How you will be supported
What an Ironman asks from you
Anyone who has done one will tell you: fitness gets you to the start line prepared. The race itself asks something else. How you respond to difficulty. How you manage the dark patches that every long-distance athlete meets. Whether you can stay present and regulated when the body is deep in discomfort and the mind starts looking for a way out.
The breathwork, the meditative practice and the inner work woven through this programme from the first session are what prepare you for that. For the second half of the marathon. For the moments when accumulated training and a clear plan are the only things between you and stopping.
People sign up for an Ironman because something in them wants to find out what they are made of. Your months of preparation, done properly, begins answering that question long before race day.
The preparation starts before you get in the water
The first thing we do is find out exactly where you are. A full fitness assessment covering your joints, mobility, flexibility, coordination, breathing mechanics and baseline endurance gives us the real picture of your starting point. We look at your history: past injuries, old restrictions, movement patterns that hold up under low volume but break down under the load of twelve months of Ironman training. From that, everything is built around what your body actually needs.
You train 2x per week with Sebastiaan in person across all three disciplines and the complementary work that makes them sustainable over time. Strength and conditioning specific to triathletes. Mobility training. Coordination and movement work that develops what we call physical intelligence: the ability to feel what your body is doing and respond to it accurately. This is what keeps you healthy and progressing when the volume gets serious.
Your training zones are established through VO2max and lactate threshold testing, giving us your maximal oxygen uptake, peak power output and lactate curve. Every session has a precise physiological target. A DEXA scan gives you a full body composition baseline at the start, so the effect of your months of training is visible and measurable. A professional bike fitting builds your position around your specific body mechanics, protecting you from injury and ensuring that the power you generate actually reaches the road.
The coordination you would otherwise have to manage yourself
Most athletes preparing for an Ironman accumulate good support from multiple sources that never speak to each other. The physio does not know what the training schedule looks like. The nutritionist is not across the phase shift. The strength coach is working from their own logic, not yours.
Or, some people just wing it. Base their training schedule of whatever experience they have from training in the past, enriched with an AI model to provide them with a training schedule and answer to all their questions.
Essentience holds the architectural view across all of it. If you already have a strength coach or specialist, they stay and become part of the team. Information from your AI, we validate and place in context. Where additional support is needed, Essentience works with specialists for tailored advise. With Essentience, you align all your efforts through one oversight layer to the same goal, with Sebastiaan as an experience triathlete on your side. You carry the training. We carry the coordination.
What Ironman coaching through Essentience looks like
Assessment & Diagnostics
Executive Checkups by Joint Space
Private Training
Guidance & Tracking
Team / Specialist Coordination
Race Day Preparation
The Bigger Picture
Receive professional support across disciplines
Ironman Coaching
Sebastiaan Kerckhof
I have competed in multiple long-distance triathlons, including the Ironman Barcelona and Ironman 70.3 World Championships. Over the years, I have guided a range of athletes through their own long-distance journeys, from first-timers to more experienced competitors.
My approach to triathlon training is rooted in the conviction that the body needs to be prepared to perform, not just trained to complete three disciplines. Next to training for the swim, bike and run, that means developing physical intelligence and kinesthetic awareness.
Alongside sport-specific fitness, through mobility work, bodyweight training, strength and conditioning for triathletes, coordination practices, elasticity training and building the kind of resilient, adaptable body that holds up across training cycles of progressive load, the result is an athlete who arrives at race day with more than fitness.
You arrive with a body that knows itself, moves well under pressure and has the physical foundation to go the distance.
Clinical Support
Joint Space Polyclinic
We integrate with Joint Space for clinical guidance, longevity- and recovery support. You have access to manual therapies, general and functional medicine, alongside a dedicated recovery space with sauna, ice bath, infra-red and hyperbaric chamber.
In the Ironman coaching, every athlete I work with begins with an Executive Health Check-up, to first understand the current state of you body in line with what's required for optimal performance and training.
This includes 110+ biomarkers covering hormonal, vitamin, mineral, cardiovascular and metabolic systems, followed by a consultation with a functional medicine doctor. You will receive your personalised dietary and nutritional recommendations built around what your bloodwork actually shows.
From there, the clinical team of Joint Space will be informed and remains available for support throughout your training cycle. Manual therapy when the body needs recalibration, recovery modalities to accelerate adaptation and functional medicine insights to keep the inner terrain matching the outer demand.
Your first Ironman, you will never forget!
Jup, that's me. Dancing, jumping, screaming and flying over the finisih line. Ironman Barcelona was my first full distance, after having competed in the Ironman70.3 Haugesund and the World Championship Ironman70.3 in Mont Tremblant.
Everyone was there, friends, partner and family. All made their way to Barcelona for a shared experience of endurance, motivation and inspiration.
The Ironman is a metaphor for something more deep and meaningful. Now what is your reason?
The Four Pillars
Essentience guides your Ironman preparation through The Four Pillars: Body, Heart, Mind and Soul, ensuring that every dimension of your performance is developed, integrated and working in the same direction.
BODY
Movement practices
To experience
Build strength, endurance, mobility and physical resilience. You will rewire postural imbalances, restore energy and regain the confidence to perform with lasting vitality.
HEART
Meditation practices
To feel
Learn to observe thoughts and emotions without judgment and create space for more intentional responses. You will increase focus, reduce reactivity and build greater stress resilience.
MIND
Reflective practices
To understand
Develop inner peace, mental clarity, accountability and internal coherence. You will be encouraged to widen your perspective, track thought patterns and test beliefs with more agency.
SOUL
Exploratory practices
To sense
Open access to insights from a deep sense of knowing. You learn to trust your inner signals, explore metaphors and make sense of the intangible by encouraging your creative potential.
Body
Heart
Mind
Soul
What you can expect from Ironman coaching
The story: Ruben finished his first Ironman with only 6 months of training
He went from being able to swim just 1 lap of front crawl to swimming 3.8km in open water; from not even owning a racing bike to cycling 180km with 30km/h average; from only running during field hockey practice to running a full 42.2km marathon in 4 hours.
Ruben finished the Ironman in 12 hours total. And most importantly: he finished with a smile. Uninjured, with a strong body, calm mind, open heart and inspired soul.
Curious about Ironman coaching, or already have an event in mind
Reach out to me and we can discuss how I can help you. Either just one advisory call or a comprehensive Ironman coaching programme.
UAE: +971 55 708 9798 / NL: +31 6424 55 651