The Secret Behind LG's 40-Year-Old Bullpen Ace: 10 Years of Daily Training Routine That Keeps Kim Jin-seong Going Strong

The Remarkable Journey of Kim Jin-seong: From Release to Revival

At 40 years old, Kim Jin-seong of the LG Twins has become one of Korean baseball's most inspiring stories of perseverance and dedication. After being released by the NC Dinos following a disappointing 2021 season where he posted a 7.17 ERA, many thought his career was over. However, Kim Jin-seong's journey with LG has proven that age is just a number when backed by unwavering commitment and smart training methods.

In the first half of the 2025 season, Kim Jin-seong appeared in 50 games out of LG's 88 games, ranking second in the entire KBO League behind only Lotte Giants' Jung Hyun-soo with 54 appearances. His performance has been nothing short of remarkable: 3 wins, 2 losses, 1 save, 21 holds, and a 3.60 ERA while throwing 45 innings – the most among LG relievers.

What makes Kim Jin-seong's story even more compelling is his humble self-assessment. When asked to rate his first-half performance, he gave himself only 6 out of 10 points, saying he did well in crisis situations early on but struggled with inherited runners toward the end of the first half. This level of self-awareness and continuous improvement mindset has been key to his longevity.

The Daily Grind: A Decade of Unwavering Routine

Kim Jin-seong's secret to longevity lies in his meticulous daily routine that he has maintained for over 10 years. The veteran pitcher revealed his training regimen in a recent interview: 'I always do a lot of aerobic exercise. I run for 20 minutes before the game starts, and another 20 minutes after the game ends. I do strength training almost every day. I've been doing this routine for about 10 years now.'

This routine isn't just about physical preparation – it's about building what Kim Jin-seong calls 'physical savings.' He explains to younger players that strength training is like putting money in the bank: 'I tell my juniors that strength training is like saving money in your body. When things get really tough later, you can withdraw and use what you've saved through strength training.'

The consistency is remarkable. Even on Mondays when there are no games, Kim Jin-seong rarely skips his strength training routine. This dedication has allowed him to maintain his effectiveness well into his 40s, something that seemed impossible after his struggles in 2021.

Team Leadership Through Action and Example

Beyond his own performance, Kim Jin-seong has become a mentor figure within the LG bullpen. He actively seeks feedback from younger players, including asking pitcher Kim Young-woo about his pitching balance and even recording videos to learn from his teammates. This willingness to learn and adapt, even at 40, demonstrates the mindset that has kept him competitive.

Kim Jin-seong's role has been especially crucial given LG's bullpen injuries this season. With closer Yoo Young-chan and left-handed setup man Ham Deok-ju undergoing surgery before the season, and newly acquired FA signing Jang Hyun-sik dealing with ankle and back injuries, Kim Jin-seong stepped up as the reliable anchor of the bullpen alongside Park Myung-geun.

Manager Yeom Kyoung-yeop acknowledged Kim Jin-seong's contributions, noting that while the rest of the bullpen wasn't overworked in the first half, Kim Jin-seong's heavy workload would require careful management in the second half. This recognition from the coaching staff highlights just how valuable his presence has been.

Learning from Fellow Veterans: The Noh Kyung-eun Connection

One of the most interesting aspects of Kim Jin-seong's approach is his relationship with SSG Landers' veteran reliever Noh Kyung-eun, who is one year his senior from the same middle school. Both players experienced the pain of being released and successfully mounted comebacks, making them kindred spirits in the world of Korean baseball.

Noh Kyung-eun, who became the oldest hold leader in KBO League history last season, shares training and game preparation tips with Kim Jin-seong. Their conversations focus on body maintenance and efficient preparation methods, particularly important for relief pitchers who throw frequently.

Kim Jin-seong explains their philosophy: 'Relief pitchers throw a lot, so we try to throw fewer pitches before games and focus everything on the actual game situation. Now that it's summer, I also tell my juniors and catch partners to minimize throwing and go in. I discuss a lot about this with Kyung-eun hyung.'

This veteran network has proven invaluable for both players' longevity and continued success.

Statistical Excellence and Record Pursuits

Kim Jin-seong's numbers since joining LG in 2022 tell the story of a remarkable second act in his career. In his first season with LG, he appeared in 67 games with a 6-3 record, 12 holds, and a 3.10 ERA, announcing his successful comeback. The following year, 2023, was even better as he led the league with 80 appearances, posting a 5-1 record, 4 saves, 21 holds, and an impressive 2.18 ERA while helping LG win the Korean Series.

His 2024 campaign saw him maintain his high level with 71 appearances, going 3-3 with 1 save and 27 holds. Now in 2025, at age 40, he continues to be LG's most reliable reliever. Over his four seasons with LG, he has appeared in 268 games – the most in the league during that span.

Kim Jin-seong is also closing in on significant career milestones. He needs just one more hold to reach 150 career holds, which would make him the fourth player in KBO League history to achieve this feat. He's also gradually approaching the all-time holds record of 177 held by Ahn Ji-man.

When asked about the hold title race this season, Kim Jin-seong showed his team-first mentality: 'I think Kyung-eun hyung will do it again this year. He was a bit behind early in the season but has almost caught up now. Team performance is more important right now, so I'm not thinking much about the hold title.'

The Philosophy of Longevity in Professional Sports

Kim Jin-seong's approach to career longevity offers valuable insights for athletes across all sports. His emphasis on consistency over intensity, his willingness to adapt and learn from younger players, and his focus on sustainable training methods have allowed him to compete at the highest level well beyond the typical peak years for relief pitchers.

The mental aspect of his approach is equally important. Despite facing the career-threatening experience of being released, Kim Jin-seong maintained his training routine and belief in his abilities. His humble self-assessment and continuous improvement mindset demonstrate the psychological resilience required for athletic longevity.

His 'physical savings' philosophy resonates beyond baseball. The idea that consistent small investments in physical preparation pay dividends during challenging times applies to any demanding profession. Kim Jin-seong's story proves that with proper preparation, dedication, and the right mindset, age can become an asset rather than a liability.

As Kim Jin-seong continues his remarkable run with LG, he serves as both a reliable performer and an inspirational figure for younger players. His story reminds us that in sports, as in life, consistency and dedication often triumph over raw talent alone.

Looking Ahead: The Future of a Baseball Icon

As the 2025 season progresses, Kim Jin-seong remains focused on team success over individual accolades. While he currently sits second in the league with 22 holds (as of July 20), his primary concern is helping LG compete for another championship. The veteran reliever has stated that he would consider retirement when his fastball velocity drops below 140 km/h, but for now, he continues to maintain his effectiveness.

His impact extends beyond statistics. Kim Jin-seong has become a symbol of perseverance and smart training in Korean baseball. Young players throughout the KBO League look to his example when facing their own challenges and setbacks. His willingness to share his knowledge and learn from others has created a positive cycle of mentorship that benefits the entire league.

The relationship with SSG's Noh Kyung-eun represents a unique brotherhood of veteran relievers who have defied age and expectations. Their continued success challenges conventional wisdom about aging in professional sports and provides a roadmap for other veteran players seeking to extend their careers.

Kim Jin-seong's story is far from over. As he continues his daily routine of 20-minute runs before and after games, combined with his religious approach to strength training, he proves that in baseball, as in life, consistency and dedication can overcome almost any obstacle. For international fans discovering Korean baseball's depth and character, Kim Jin-seong represents everything that makes the KBO League special – resilience, respect, and an unwavering commitment to excellence.