10 minute AMRAP
Active Sonar
Core under fatigue · Midline Tension · intensity 2 of 5
The workout
As many rounds as possible in 10 minutes of:
Overview
Active Sonar is 16 alternating bird-dogs, 12 t-press ups, and 16 slow dead bugs. The work moves through the midline and the upper back instead of sitting on one muscle.
Muscles worked
Midline
Upper back
Energy systems
These are overlapping contributions. This workout is not assigned to one energy system.
This workout departs from its style on the profile below.
- Glycolytic: Low
- Oxidative: High
- Neuromuscular: Moderate
Training effect
Immediate demand
10 minutes, intensity 2 of 5. Today the limiter is the sets being the same size.
Intended stimulus
The style is built so a trunk position has to survive the moving reps. On this workout that is 16 alternating bird-dogs, 12 t-press ups, and 16 slow dead bugs.
Repeated practice
Repeat the same workout and compare the score. What can change over weeks is how long that pace lasts. One time through does not produce that change.
Body-composition context
Body weight changes with the rest of how you eat and train. This workout is one piece of work on one day.
Expected feel
The sets are the same size. The round gets hard when one of them breaks.
Pacing
Structural flush — continuous low-intensity core and posterior work. Reach long on the bird-dogs; arms stay heavy on the T.
Keep each round about the same length. Do not drop the alternating bird-dogs to keep the other sets moving.
The movements
Alternating Bird-Dogs
Reach long, not high. Hyperextending the back to get your leg higher defeats the core stabilization purpose entirely.
What not to do. Lifting the arm and leg above the line of the back, which arches the spine.
T-Press Ups
The range of motion on this is naturally very short. Do not force your chest higher by straining your neck. Focus entirely on the squeeze in the back of your shoulders.
What not to do. Craning the neck to force the chest higher than the rear delts can drive.
Dead Bugs (Slow)
Speed is your enemy here. Move deliberately to maximize time under tension.
What not to do. Letting the extended arm and leg drop fast rather than lowering slowly.
Why these movements
The work moves through the midline and the upper back instead of sitting on one muscle.
Scaling
Keep a brace or a hollow position in every round. Drop the moving reps before you drop the position that makes the trunk work.
Alternating Bird-Dogs
- Shorter range. Lift only as high as you can hold the position without arching the back.
- Both legs. Drive through both feet instead of one.
T-Press Ups
- Shorter lift. Drive into the floor but only lift as high as you can control without the hips or neck cheating.
- Hold the squeeze. Reach the top and freeze for a count instead of cycling reps. Same drive, less fatigue management.
Dead Bugs (Slow)
- Knees bent. Bend the knees to shorten the lever. The shorter it is, the lighter it is.
- Partial range. Move only through the range where you can keep the lower back on the floor.
Mistakes and who it is for
- Opening the alternating bird-dogs at a sprint makes the alternating bird-dogs the piece that falls apart.
- Resting until you feel fresh between movements removes the point of keeping them in one round.
- Letting the alternating bird-dogs shrink so the rest of the round can speed up changes the workout on the page.
Suited to someone who wants 10 minutes through Alternating Bird-Dogs, T-Press Ups, Dead Bugs (Slow).
Scoring and progression
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.
Progression is repeating this workout and comparing that score. The page does not promise a change from one time through.
Related workouts
- Iron Scapula
Same midline and upper back, same clock
- Dorsal Span
Same midline and upper back, longer clock
- Iron Scapula Grind
Same midline and upper back, longer clock
Run it with friends
Active Sonar runs on a shared countdown: share a rally link, everyone gets the same 10-minute clock, and the leaderboard updates as people log rounds.