“If you'd told me at diagnosis I'd end up competing in sumo for England, I wouldn't have believed you.”
Nathaniel competes internationally for England in sumo and has lived with Type 1 Diabetes for nearly 15 years. Having managed it through rugby and American football before taking up sumo, he talks us through the challenge of maintaining blood sugar across a full competition day, the stress spikes that catch him out between bouts (matches), and why he doesn't let diabetes shape his ambitions.
A note: what works for Nathaniel reflects his own experience and physiology, developed over years of living with T1D. It isn't a set of instructions to copy, as everyone's management is different, and any changes to insulin or routine should only be made with your own diabetes team.
This is Nathaniel's Hypo Diary…
How long have you lived with Type 1, and how has managing it changed as you've got more serious about sport?
It's been close to 15 years now. I've been playing sport since I was six or seven, so diabetes has been part of that for me. What’s changed is the types of sport I’m doing and what that demands from my management. I went from rugby, to American football, and now sumo.
American football is a long game, often running several hours with little breaks in between, whereas with sumo you can be competing across an entire day, with long gaps between bouts depending on your category. So I’ve had to adapt how I manage my diabetes, particularly around staying in the right range and being ready to compete throughout the whole day, rather than just managing it around a single game.
How did you get into sumo?
Pretty randomly. I'd wanted to try it for a while and emailed the federation, but the nearest club was in London, which was too far at the time. Then a friend I play American football with shared an Instagram post about a new club in Southampton, and I went along. From there it moved quickly: a bronze medal at the British Isles Championships, another at the English nationals, then selection to compete for England at the European Championships. I'm in the light heavyweight category but have also competed in the open, and I'm not a heavyweight, so going up against guys who are 180 to 200 kilos is tough. But you find ways to do it. It's hard at times, but it's so rewarding. I love it.
How does preparing for sumo with T1D differ from other sports?
The main thing is maintaining blood sugar throughout the whole day. In longer sessions there's a gradual build-up: warm-up, general technique, then eventually you get into bouts, and that's hardcore conditioning. I have to keep a close eye on my levels through that, because as soon as I get a break, I'll check my sensor and see it dropping.
The other thing I've noticed, and had with American football too, is stress spikes between categories or breaks. Stress pushes your blood sugar up, so you're deciding whether to correct it with insulin. Those are the tricky ones though, because once your body relaxes and the stress hormone naturally dissipates, you can end up going hypo from over-correcting.
What's it like having a hypo when you're competing?
In the moment, I just get on with it. The brain fog is there, but I have to consciously push through it and get my head back in the game.
I've had a hypo just before an American football game was about to start, trying to get my blood sugar up in time to run straight out onto the field. That's a really hard balance. In sumo, I try to catch it before it gets anywhere near that point at all.
Is there anything about managing T1D alongside sport that people don't really get?
People don't expect to see me taking on sugar at random points in a session. They're used to jelly babies or a drink at half-time, not mid-training, and needing that much sugar that quickly, rather than a sports gel, seems to throw them. Not in a malicious way, it's just not what they're used to seeing.
How do you track your blood sugar while you're actually wrestling?
I keep my sensor on, but I protect it. I've cut a thermal sleeve in half so it covers just the top of my arm and shoulder for training, and for competitions I'll tape over it as well. I always carry a blood sugar reader with me, and a spare sensor for afterwards, because sensors do get ripped off during grappling.
That's actually why I haven't gone for a pump. With that much grappling, it's one more thing that could get caught or pulled at. Right now, injections just fit better for what I do.
How is competing internationally changing how you manage your diabetes?
The extra packing is the main thing. International competitions are harder, since it's much more difficult to get hold of supplies if you run out. Airports add their own stress too. Rushing to catch a flight pushes levels up, but the rushing itself can also send you low, so I keep a much closer eye on things when I'm travelling.
What are you hoping to achieve in sumo over the next few years?
I'd like to push for a higher medal at the British and English nationals, and re-solidify a spot on the England team. A good result at the British could put me in contention for a Great Britain place at the World Championships. In a month I'll be competing at the Swiss Open: always good to try something new.
What are you proudest of, in how you've managed Type 1 alongside what you've achieved in sumo?
Just not giving up. Getting to the point where I've represented my country internationally is huge for me. It's something I've always wanted, and sumo is where I found that.
What's one thing you wish more people understood about competing at a high level with T1D, and what would you say to a young person worried it might hold them back?
That you have to think so much more about everything, in life generally, not just sport, before you even step onto the field, and it doesn't stop when you come off it. I might finish a session, get home, have a shower, and then go hypo because of the exercise. There's a lot more decision-making involved than people realise: what you eat, what you drink, how far you're walking, what you need to take with you.
I always go back to what a doctor told me after I was diagnosed: it shouldn't shape your life, and you can still live it as if you weren't diabetic. Seeing more people wearing CGMs now, in football and other sports, makes it clear how many people are in a similar position and still achieving things. My advice is to get stuck in and try everything. If you'd told me at diagnosis I'd end up competing in sumo for England, I wouldn't have believed you.
Nathaniel has been trying Klario™ alongside his training, and plans to take it with him when he competes internationally, starting with the Swiss Open.
Thank you to Nathaniel for sharing his Hypo Diary with us. We'll be following his season as it continues, so stay tuned.
Living with Type 1 and have a story to tell? We'd love to feature your Hypo Diary. Get in touch at support@myklario.com