A Japanese man has revealed to the world how he turned his dad bod into a lean, mean eight-pack abs machine.

He claimed all credit goes to a daily four-minute workout.

The man shared his method on Twitter, where his handle is "Hiiragi Sensei", which means Teacher Hiragi.

He posted about his progress in a series of tweets on Aug. 25.

4-minute high-intensity interval training every day

Hiragi shared that he had been doing this four-minute high-intensity interval training (HIIT) workout at home every day for five months, from March to August 2019.

Along with the tweets, he shared two photos of him to demonstrate the transformation.

Before starting on the workout, he had a potbelly.

Five months later, the photo shows a muscular body with eight-pack abs.

#私はここまで成長しました見た人も晒す
2019年3月→2019年8月

5ヶ月程度
家での筋トレだけでも、そこそこ変われたよね

今回は、ほぼ同じ場所と角度で撮影した！無修正やで(´・ω・`)

アップルウォッチで撮影してるから、ポーズはこんなんになっとるw pic.twitter.com/L5jQgnqEzW

— 柊せんせー (@hiiragisensei) August 25, 2019

"From March 2019 to August 2019.

Progress within 5 months

Even with strength training done at home, this much can be achieved.

The two photos here were taken from the same place and pretty much the same angle! No edits done. (´・ω・`)

I took the pictures using Apple Watch, which is why I'm posing this way."

He also shared a video of the four-minute workout that he did daily on YouTube:

5カ月程度で、これだけ変われたわけだけど、実は2年間ぐいらいは、痩せる痩せる詐欺していて、全然ダイエットすることが出来なく三日坊主の連続だった

今、思うと本気で痩せる気がなかっただけだと思う。明確な目標を立てて程ほどに行動すれば、大体のことは達成出来る

無謀な目標は、ダメだけどねｗ

— 柊せんせー (@hiiragisensei) August 25, 2019

Diet matters too

Hiragi's transformation is also due to a change in diet, as it was definitely not just about doing exercises conscientiously.

Hiragi consumes 1,000 to 1,500 calories by cutting down on other foods and eating more vegetables, which are low in calories.

He only eats between 12pm and 8pm, two meals a day.

He also tries to avoid having sweet drinks, snacks, and desserts.

今日の昼ご飯です

朝は、ブラックコーヒーと緑茶と水だけで過ごすので、この昼がはじめての食事です。

昼はこんな感じにしておけば、夜は多少外食行ったりしても問題ないかと思います。

味付けは、塩胡椒とオリーブオイルね！ pic.twitter.com/fQ2VhF99fG

— 柊せんせー (@hiiragisensei) August 28, 2019

"Today's lunch. I only drank black coffee, green tea and water this morning, so this is my first meal of the day.

If you have something like this for lunch, I think you can afford to dine out at night.

As for seasoning, I used salt, pepper and olive oil!"

That does not mean he leads a pathetic life, Hiragi still indulges occasionally such as eating grilled meat or curry rice and drinking bubble tea.

夜ご飯は、焼肉とタピオカミルクティにしました。

たまには、こんなの食べても毎日運動してるから痩せたのかな

まぁぼっち飯なんやけどなw pic.twitter.com/YDNFDRx8lb

— 柊せんせー (@hiiragisensei) August 27, 2019

タピオカ買ってきた！

黒糖のタピオカが好きで、ダイエット時でもよく飲んでたw

それでも痩せたのは、毎日の運動やな🥺

ちなみに、言っとくが俺はソロだ pic.twitter.com/m8SnURhNch

— 柊せんせー (@hiiragisensei) August 29, 2019

今日の晩御飯は、ココイチのほうれん草チーズカレー🍛にした！

毎回ガッツリした食事制限でなくても、普通に痩せるよ‼️ pic.twitter.com/7CCENQgabK

— 柊せんせー (@hiiragisensei) August 28, 2019

It's all about being disciplined

While the four-minute workout sounds pretty doable, doing it every single day does take some determination.

It's after all about getting sufficient exercise and diet control, which one has to set his or her mind to do so.

Hiragi shared that he has the interest to lose weight for the past two years, but he realised he was not serious about doing it before.

Now with a clear goal and routine, he has finally achieved it.

5カ月程度で、これだけ変われたわけだけど、実は2年間ぐいらいは、痩せる痩せる詐欺していて、全然ダイエットすることが出来なく三日坊主の連続だった

今、思うと本気で痩せる気がなかっただけだと思う。明確な目標を立てて程ほどに行動すれば、大体のことは達成出来る

無謀な目標は、ダメだけどねｗ

— 柊せんせー (@hiiragisensei) August 25, 2019

"I changed this much within five months, but I've actually been lying to myself for the last two years, saying that "I will lose weight, I will lose weight". I couldn't last longer than three days whenever I tried to diet, and the cycle repeats itself.

Now that I think about it, I just wasn't really serious about losing weight. As long as I've a clear objective, and I set out to achieve it, I can more or less do it."

Top photo from Twitter @hirragisensei