Resisted & Assisted Sprinting

Two families of methods modify the load on sprinting to target specific qualities:

Resisted sprinting adds resistance, biasing force production and acceleration:

• Tools: weighted sleds/prowlers (push or tow), uphill sprints, resistance-band sprints, parachutes, weighted vests, sand running.
• Effect: exaggerates forward lean, ground-contact time, and horizontal force; develops the drive/acceleration phase and lower-body power. Loads should generally be light enough not to grossly distort sprint mechanics (a common guideline is to keep velocity loss modest for speed transfer; heavier loads shift toward strength-speed/acceleration).

Assisted (overspeed) sprinting reduces effective resistance so the athlete moves faster than normal, biasing stride frequency and the max-velocity end:

• Tools: gentle downhill sprints (small grade), towing with a band/partner, high-speed treadmills.
• Effect: trains the nervous system at supramaximal velocities. It carries higher risk (loss of control, over-striding, hamstring strain) and must use only small grades/over-speeds (often cited ≤ ~10% faster), good surfaces, and well-prepared athletes.

Both are advanced supplements to free sprinting, used in short, fully-recovered, high-quality efforts placed early in the session.

• Resisted: sleds, hills, bands, parachutes, vests — overload force/acceleration.
• Assisted/overspeed: downhill, towing, fast treadmills — overload stride frequency/top speed.
• Keep resistance from grossly distorting mechanics; keep overspeed small (≤~10%).
• Assisted work is higher-risk (control, over-striding, hamstrings) — advanced athletes only.
• Use short, fully-recovered, high-quality reps early in the session.