The Thames is set to become the battleground for an extraordinary sibling rivalry this Saturday as sisters Lilli and Mia Freischem go head-to-head in the historic Boat Race, vying for what they describe as “ultimate bragging rights”.

The unique clash sees Mia representing Cambridge, hoping to extend their dominant nine-year winning streak, while older sister Lilli, rowing for Oxford alongside world and Olympic medallist Heidi Long, aims to finally overturn the tide.

This year marks a rare occasion, with the Freischems being the first sister-opponents in 22 years.

Despite the intense competition, their family loyalty remains firmly rooted in both camps, symbolised by the handcrafted half-and-half Oxford and Cambridge jumpers they presented to their parents at Christmas.

Mia, nearly two years Lilli’s junior, expressed the profound excitement surrounding their impending duel.

“From the moment we realised it could be a possibility that we were racing each other, I think we were both just so excited, and, if anything, it would make us work harder to try to make it happen,” she told the Press Association.

“It’s just such a special thing to know that you get to race against someone that you know so well. Since this is Lilli’s last year of her PhD, this is the race for the ultimate bragging rights. This is the one that we get.”

Lilli confirmed this will be their first sporting confrontation beyond informal family contests, such as impromptu 100-metre sprints during holiday hikes or “speed-walking competitions, or trying to cycle as slow as possible.”

The sisters initially played football together before Mia followed Lilli into rowing during their undergraduate years at the University of Edinburgh, a pursuit that began as a hobby to combat the inertia of the Covid-19 pandemic.

Lilli, an atmospheric physics PhD student, joined Oxford’s rowing club with just a year’s experience, admitting, “they do the Boat Race, but surely they’re all crazy athletes. I just kind of hoped I could continue improving and they wouldn’t send me away. I really didn’t think I’d be racing for Oxford.”

Both sisters acknowledge the initial challenge of balancing their shared passion for rowing with the need to keep competitive secrets from their rival crews.

Mia, who is pursuing a PhD in surgery, explained their approach: “There are definitely things and parts of the programme that maybe you don’t go into in so much detail, but I think we’ve really found a way of sharing our individual tasks and journeys with each other, rather than how the club approaches the Boat Race. The two then don’t stand in each other’s way. It’s more about how we can support each other as athletes and as people.”

The family has meticulously planned their support strategy to ensure an “equal split.”

Last year, their parents attended the Oxford dinner following Lilli’s debut in the dark blue boat. This time, Lilli will be “setting them free” to dine with debutant Mia and the Cambridge team, while she hosts their beloved cousins.

Come race day, their parents will proudly display their unique half-and-half jumpers.

“We made sure they could support us without having to choose,” Mia added. “If you see anyone around in light blue and dark blue, those are definitely our parents!”