Super Slow / High-Intensity Training (HIT — Body by Science) — Exercise & Movement
Ultra-slow repetition resistance training (10s up / 10s down) to muscular failure, requiring only one 15-20 minute session per week.
Overview
Super Slow / HIT training, popularized by Doug McGuff in 'Body by Science,' prescribes performing resistance exercises with extremely slow repetition speeds (10 seconds concentric, 10 seconds eccentric) to momentary muscular failure on 4-6 machine-based compound exercises, completed in a single weekly session of 12-20 minutes. The slow speed eliminates momentum, ensuring continuous muscle tension and maximizing time under tension. ARX (Adaptive Resistance Exercise) machines represent the technological evolution of this approach, providing computer-controlled accommodating resistance. Proponents argue this minimal-dose approach provides sufficient stimulus for strength and metabolic improvement with dramatically reduced time investment and injury risk.
Indications
- Time-efficient strength maintenance
- Minimalist resistance training approach
- Joint-friendly loading (no momentum or impact)
- Metabolic conditioning via deep muscle fatigue
- Appropriate for time-constrained individuals
Mechanism of Action
Eliminating momentum ensures muscle fibers remain under constant tension throughout the entire range of motion
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Body by Science Protocol | 5 exercises to failure (12-20 min total) | 1x/week | 10s concentric / 10s eccentric; 60-90s time under load per exercise |
Safety & Contraindications
- Training to true muscular failure requires mental fortitude and may cause nausea initially
- Blood pressure can spike significantly at point of failure — caution in hypertensive individuals
- Ensure machines are properly adjusted before starting
- Not optimal for developing power, speed, or sport-specific skills