Japanese Breaststroking Ace Koseki Modeling Gym Training After Peaty

Last month, Japan’s new high-altitude swimming facility of Yunomaru Kogen Sports Exchange in Tomi City opened its doors for business. And one of the nation’s top breaststrokers, Yasuhiro Koseki, is wasting no time taking advantage of the opportunity to train at the $11 million complex positioned at an elevation of 1750 meters (~5741 feet).

But venturing into high-altitude territory isn’t the only tactic Koseki is incorporating into his training regimen to potentially make his mark on a home nation-hosted Olympic Games.

As reported by Sanspo, 27-year-old Koseki has been carefully studying the training methods of British breaststroking beast Adam Peaty, both in and out of the pool. Peaty is the reigning Olympic champion in the 100m breaststroke, the event in which Koseki took gold at the 2018 Pan Pacific Championships.

Peaty is also the man who has been simply untouchable in the 100m breast event, owning the fastest time ever by a mile with the 56.88 he produced at the 2019 FINA World Aquatic Championships in Gwangju, Korea.

Last year SwimSwam analyzed Peaty’s actual stroke, noting how the Loughborough athlete is able to reduce the time of his breaststroke recovery without wasting any propulsion, enabling him to have more time to glide. Bottom line, Peaty’s technique in the water is the gold standard, of which you can read more about here.

But the Brit is also known for his disciplined training in the gym, with his chiseled physique and broad chest easily recognizable on pool decks around the world.

Rivals like Koseki are taking notice and taking action.

“It’s simple. Peaty is working with weights, so I’m going to work with weights,” said Koseki to Sanspo this week. Specifically, Koseki points to Peaty’s hanging on a bar with weights attached to his hips, a move he has started undertaking as well.

You can see the exact exercise demonstrated by Peaty in the video below, courtesy of Loughborough University:

Koseki began performing the exercise last November, performing 15 pull-ups with about 25kg (55 lbs) suspended from his waist, specifically focusing on his latissimus dorsi muscle.

Peaty has said about pull-ups,“[They] improve my upper-body strength…..connecting the muscles on the front of my torso with my back muscles, which also plays an important part in catching the water.

“Always try to get your chin across the bar. If you’re not doing that and you’re not going all the way down you’re shortening your movement. And you can also hold at the top for an isometric pause.”

Koseki will need all the ammo he can arm himself with, as the breaststroking competition within his own nation has gotten intensely fierce over the past few years. In addition to his mainstay rival Ippei Watanabewho formerly held the 200m breast world record, a young gun in 18-year-old Shoma Sato has also emerged on the scene.

Just last week Sato threw down a big-time mark of 2:07.58 to throw his hat into the ring of potential Japanese swimmers to represent the nation on the biggest international sporting stage fewer than 175 days from now.

Lifetime Bests of Yasuhiro Koseki:

  • 58.78 100m breast from 2018 Mare Nostrum – Monte Carlo (current JPN national record); 12th fastest performer all-time
  • 2:07.18 200m breast from 2017; 6th fastest performer all-time

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15 reps with 25kg is insane, I doubt it’s true.


Was thinking the same thing! I’ve done 30+ regular pull ups and I don’t know that I can do more than 5 or 6 with 25kg. No way is he doing 15.


Maybe he means 3×5 reps and just totaling what he does together?

Jorgen brathen

As a relatively high level breaststroke sprinter, i am sure This is true. I can lift 12×25 and while my 50 is semi-close to Koseki my 100 is way of. Anyway that is the level to reach if you want to Swim fast breaststroke..

Samuli Hirsi

why? you are an individual.

About Retta Race

Retta Race

After 16 years at a Fortune 1000 financial company, long-time swimmer Retta Race decided to change lanes and pursue her sporting passion. She currently is Coach for the Northern KY Swordfish Masters, a team she started up in December 2013, while also offering private coaching. Retta is also an MBA …

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