- Aug 15, 2018
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Most programming debates are about sets, reps, and load. The eccentric phase — the lowering, lengthening part of a lift — has its own research literature, and it suggests the way down does things the way up can't.
Eccentrics have a few unique properties. Muscles can handle roughly 20–40 % more load eccentrically than concentrically, eccentric contractions cause more structural disruption (part of why unaccustomed lowering work produces legendary soreness), and chronic eccentric training changes the muscle itself: studies by Franchi and colleagues showed that eccentric-heavy training tends to add sarcomeres in series — lengthening fascicles — while concentric training adds them in parallel. Longer fascicles are associated with better sprint mechanics and, in prospective work on hamstring injuries (Timmins and colleagues, 2016), longer biceps femoris fascicles and stronger eccentrics were linked to substantially lower injury risk in field-sport athletes.
The injury-prevention data is the strongest practical argument. Meta-analyses of Nordic hamstring exercise programmes (Al Attar and colleagues, British Journal of Sports Medicine, 2017) found injury risk reductions of up to roughly half in teams that actually complied with the protocol — one of the largest effect sizes for any single exercise intervention. Similar heavy-eccentric and heavy-slow protocols are staples of tendon rehab, where controlled lowering loads the tendon in a way that tends to reduce pain over 12-week blocks.
The honest limitations: eccentric overload methods (flywheels, accentuated eccentric loading, weight releasers) show small-to-moderate advantages over conventional training in meta-analyses, mostly in trained subjects, and the effects aren't dramatic enough to justify rebuilding a program around them. And novel eccentric work is the fastest route to crippling soreness, which can wreck the rest of a training week if dosed carelessly — the repeated bout effect means the second session is far less damaging than the first, so ramping matters.
Do you program eccentrics deliberately — slow negatives, Nordics, flywheel work — or is the lowering phase just however it happens on the way down? Anyone using them specifically to keep a problem tendon or hamstring quiet?
Eccentrics have a few unique properties. Muscles can handle roughly 20–40 % more load eccentrically than concentrically, eccentric contractions cause more structural disruption (part of why unaccustomed lowering work produces legendary soreness), and chronic eccentric training changes the muscle itself: studies by Franchi and colleagues showed that eccentric-heavy training tends to add sarcomeres in series — lengthening fascicles — while concentric training adds them in parallel. Longer fascicles are associated with better sprint mechanics and, in prospective work on hamstring injuries (Timmins and colleagues, 2016), longer biceps femoris fascicles and stronger eccentrics were linked to substantially lower injury risk in field-sport athletes.
The injury-prevention data is the strongest practical argument. Meta-analyses of Nordic hamstring exercise programmes (Al Attar and colleagues, British Journal of Sports Medicine, 2017) found injury risk reductions of up to roughly half in teams that actually complied with the protocol — one of the largest effect sizes for any single exercise intervention. Similar heavy-eccentric and heavy-slow protocols are staples of tendon rehab, where controlled lowering loads the tendon in a way that tends to reduce pain over 12-week blocks.
The honest limitations: eccentric overload methods (flywheels, accentuated eccentric loading, weight releasers) show small-to-moderate advantages over conventional training in meta-analyses, mostly in trained subjects, and the effects aren't dramatic enough to justify rebuilding a program around them. And novel eccentric work is the fastest route to crippling soreness, which can wreck the rest of a training week if dosed carelessly — the repeated bout effect means the second session is far less damaging than the first, so ramping matters.
Do you program eccentrics deliberately — slow negatives, Nordics, flywheel work — or is the lowering phase just however it happens on the way down? Anyone using them specifically to keep a problem tendon or hamstring quiet?