Bodyweight Ab Workout: The 400 Rep Challenge
Summary
Jeff Cavaliere of ATHLEANX presents a 400 Rep Ab Challenge to mark the channel’s 400th video milestone. The workout consists of four bodyweight exercises performed entirely on the floor, repeated twice through for a total of 400 reps. The goal is to complete all 400 reps as fast as possible and track your time for future improvement.
Key Points
- No equipment required — the entire workout is done on the floor, eliminating all excuses related to gym access
- Four exercises, 50 reps each, performed twice — the first round totals 200 reps, and the second round completes the 400
- Time-based format — record your finish time and use it as a personal benchmark to beat in future attempts
- Upper and lower abs are both targeted — exercises are selected to hit the full range of the core, including rotational and lower ab movements
- Momentum is the enemy — form cues consistently emphasize using ab strength rather than swinging or throwing limbs to generate force
- Progressive improvement is the goal — the challenge is designed as an objective measurement tool to track fitness progress over time
Exercise Details
1. Ten Touch Twist
- Target muscles: Obliques, upper abs
- How to perform: Lie on your back with legs extended. Only the lower back touches the floor — mid and upper back remain elevated. Rotate the entire upper torso left and right, touching all 10 fingers to the ground on each side
- Key form cue: Rotate the whole torso, not just the arms — avoid simply reaching with your hands
- Reps: 50
2. Butterfly Sit-Up
- Target muscles: Abs (general), with emphasis on upper core
- How to perform: Perform a sit-up with legs in a butterfly position. At the top, externally rotate the shoulders and open up
- Common mistake: Throwing hands forward to generate momentum — this reduces ab engagement
- Key form cue: Let momentum carry you backward and use ab strength to overcome it on the way up
- Reps: 50
3. Scissors
- Target muscles: Lower abs
- How to perform: Lie on your back and alternate crossing one foot over the other in a scissor pattern — over, under, back and forth
- Rep counting note: Each individual over-and-back movement counts as 1 rep, meaning 100 individual movements to reach 50 reps
- Reps: 50
4. Twisting Piston
- Target muscles: Lower abs, obliques
- How to perform: An explosive lower body rotational movement — each twist to the left and each twist to the right counts as 1 rep
- Key quality: Explosive and rotational — engages the core dynamically
- Reps: 50
Full Workout Structure
| Round | Exercise | Reps |
|---|---|---|
| 1 | Ten Touch Twist | 50 |
| 1 | Butterfly Sit-Up | 50 |
| 1 | Scissors | 50 |
| 1 | Twisting Piston | 50 |
| 2 | Repeat all four | 200 |
| Total | 400 |