Hokuto Shinken practitioners (Fist of the North Star)
Walter C. Dornez (Hellsing)
Sairaorg Bael (Highschool DxD)
Akisame (History's Mightiest Disciple Kenichi)
Cipher Pol Agents (One Piece)
Many characters (One Piece)
Saitama (One-Punch Man)
Ranma Saotome (Ranma 1/2)
Many characters (Rurouni Kenshin)
Fake Assassin (TYPE-MOON)
Genkai (YuYu Hakusho)
Yusuke (YuYu Hakuhso)
Shinobu Sensui (YuYu Hakusho)
Lady (Devil May Cry)
Many characters (Dead or Alive/Ninja Gaiden)
Many characters (Metal Gear)
Many characters (Resident Evil)
Many characters (Street Fighter)
Many characters (Tekken)
Ezio Auditore da Firenze (Assassin's Creed)
Ratonhnhaké:ton (Assassin's Creed)
Segata Sanshiro (Sega)
Hayley Smith (American Dad!) is a sleeper agent from Project Daycare, trained to be an unstoppable killing machine, in which she proved in her attempt at her father's life upon her programming malfunction.
Even without using Venom, Bane (DC Comics) possesses nigh-superhuman physical abilities due to training.
The Karate Kid (DC Comics) possesses such skill in martial arts that he can damage solid rock and metal, as well as briefly hold his own against Kryptonians.
Jann Lee (Dead or Alive) is strong enough through training to beat a T-Rex unconscious with his bare hands.
Goku (Dragon Ball series) was taught by Grandpa Gohan in martial arts and ki training, by Korin in endurance and opponent anticipation, by Master Roshi in Kame-Sennin Ryu to push his body to superhuman levels, by Mr. Popo and Kami in ki sense, mediation, precision, and Bukūjutsu to fly, and by King Kai in the Kaio-ken and Spirit Bomb.
Master Roshi (Dragon Ball series) achieved superhuman status through training, to the extent that he was once hailed the strongest man in the world.
Though nowhere near the Z-Fighters' level, Hercule (Dragon Ball series) is nonetheless more powerful than an ordinary human thanks to his training, able to pull off such feats as moving faster than the eye can see, pulling a line of four buses several feet with his bare hands, and survive hits from Perfect Cell and Kid Buu.
Those who practice Hokuto Shinken (Fist of the North Star) train to unlock and use their bodies' full muscle potential.
Even in old age, Walter C. Dornez (Hellsing) possesses superhuman speed and acrobatic skills due to years of training and experience.
Akisame Koetsuji (History's Strongest Disciple Kenichi) has trained his body to that point that he has absolutely no unnecessary/useless muscle, as every single inch of his frame is composed of only pink muscle. Granting him nearly superhuman skills equal to the Elder.
Through training, Solid Snake (Metal Gear) is able to pull off feats such as dodging bullets from multiple ranges and withstanding electrical torture.
Even without his Devil Fruit powers, Monkey D. Luffy (One Piece) possesses incredible strength and skill as a result of a training regimen his grandfather put him through.
Saitama (One-Punch Man) broke through his human limitations and achieved unbelievable strength and abilities considered impossible through an extensive training regimen.
Through extensive physical training, Chris Redfield (Resident Evil) possesses sufficient strength to move boulders several times his own height and weight.
Segata Sanshiro (Sega) has trained so extensively in martial arts that he can pull of a variety of superhuman/supernatural feats, such as causing those he throws to explode on impact with the ground, kick a baseball for a home run, and survive in the vacuum of space unaided.
Through The Hercules Method, Luther Strode (The Strange Talent of Luther Strode) developed physical and mental abilities beyond any normal human.
Ryu (Street Fighter) has trained extensively in the Ansatsuken fighting style, bestowing such abilities as Ki manipulation.
Though elderly, Heihachi Mishima (Tekken) possesses incredible strength and electrical powers due to his training in Mishima-Style Fighting Karate.
Genkai (YuYu Hakusho) is an incredibly skilled matrial artist known to humans and demons alike. Her personal Reihado-ken fighting style allows her to revert her body its peak. She is also a harsh teacher with grueling, but beneficial, training methods.
Yusuke Urameshi (YuYu Hakusho) went through hard training under the teachings of Genkai, but in turn was able to learn the Spirit Shotgun, Spirit Wave, and had his Spirit Energy greatly improved by the aid of her Spirit Cuffs.
Shinobu Sensui (YuYu Hakusho) is a master of the Resshūken fighting style, which is said to be to be the strongest, most elegant, school of martial arts in existence. In addition to this, he was able to master the Sacred Energy with only six years of discipline instead of the usual forty.
Karnak Mander-Azur (Marvel Comics) is the only inhuman who did not undergo terrigenesis as he came of age, all his powers and abilities come from decades of intense physical and mental strengthening regimens he partook throughout his life.