Which heavyweight boxer had the hardest training routine

Determining which heavyweight boxer had the hardest training routine can be subjective, as training regimens can vary significantly and may be influenced by personal preferences, coaching styles, and physical conditioning. However, several heavyweight boxers are often cited for their intense training regimens:

**Muhammad Ali**: Known for his incredible work ethic and innovative training methods, Ali's routine included long runs, sparring, shadowboxing, and a variety of exercises. He would often train in the early mornings and incorporated unconventional techniques like swimming and rope skipping.

**Mike Tyson**: Tyson’s training under Cus D'Amato was famously grueling. Tyson started training at a young age and followed a strict daily routine that included running, heavy bag work, and intense sparring. His workouts often began early in the morning and included extensive conditioning.

**George Foreman**: Foreman was known for his punishing training routine that included running, weight lifting, and high-intensity sparring. His dedication to training was a significant factor in his success, especially during his comeback in the 1990s.

**Deontay Wilder**: Known for his explosive power, Wilder’s training has included rigorous strength and conditioning exercises, extensive cardio, and heavy sparring. He often incorporates unconventional methods like resistance training and plyometrics.

**Sonny Liston**: Liston was known for his tough upbringing and equally tough training routines. He would often run long distances and train in tough environments to build endurance and strength.

Each of these boxers exemplifies a dedication to their sport and the depth of their training philosophies. Ultimately, the "hardest" training routine may vary depending on individual perspectives, but all mentioned were known for their intense dedication and discipline.