15 minute AMRAP
The Piston Grind
Blood Shunt · intensity 3 of 5
The workout
As many rounds as possible in 15 minutes of:
How to run it
Slow, heavy tension on the floor before a rapid core flush.
Work through the movements in the order listed, then start the next round. Your score is the number of complete rounds plus any reps of the round you were partway through when the clock hit zero — written as rounds plus reps, so seven full rounds and twelve reps is7+12.
The movements
Glute Bridges
"Pinch a coin between your glutes at the top." If you just thrust your hips recklessly, you will hyper-extend your lumbar spine.
Keep your toes slightly elevated off the floor to force the drive exclusively through your heels and hamstrings.
Dive-Bomber Push-ups
"Slide under the barbed wire, then back out." It is a two-way fluid motion.
This is a slow, tension-heavy movement. Focus on continuous, unbroken motion rather than speed.
Mountain Climbers
"Run on the wall." Imagine you are sprinting vertically. Do not let your hips bounce up and down like a seesaw.
Keep your shoulders stacked directly over your wrists. If you drift backward, you lose leverage and the movement slows down completely.
Scaling it
Every movement here is bodyweight, so the scaling lever is volume rather than load. If a round is taking longer than about ninety seconds, halve the reps and keep the round count moving — the point of an AMRAP is continuous work, and a round you grind through in four minutes teaches you less than three rounds at a pace you can repeat.
Run it with friends
The Piston Grind runs on a shared countdown: share a rally link, everyone gets the same15-minute clock, and the leaderboard updates as people log rounds.