Eccentric exercise is any movement where your muscles lengthen while under load. Think of lowering a dumbbell during a bicep curl, descending into a squat, or walking downhill. Your muscles are still working hard, but instead of shortening to lift a weight, they’re stretching in a controlled way to resist gravity or an external force. This “lowering phase” of strength training turns out to have unique benefits for building muscle, strengthening tendons, and recovering from injury.
How Eccentric Contractions Work
Every strength exercise has two main phases. The concentric phase is when you lift, push, or pull a weight. The eccentric phase is when you lower it back down. During that lowering phase, your muscle fibers are being pulled apart while they’re still trying to hold tension. The tiny protein structures inside your muscles act like elastic springs, storing energy as they’re stretched. Once they reach a certain point of stretch, they detach and reattach, generating force the entire time.
What makes this interesting is that your muscles can actually handle more weight during the eccentric phase than during the lifting phase. You’ve probably noticed this: you can lower a heavier barbell to your chest much more easily than you can press it back up. This capacity for higher force production is one reason eccentric training produces such distinctive results.
Why Eccentric Training Builds More Muscle
Eccentric contractions create more mechanical tension in your muscle fibers at a cellular level, and that tension is a primary driver of muscle growth. A meta-analysis in the Journal of Strength and Conditioning Research compared eccentric-only and concentric-only training across multiple studies and found that eccentric training produced an average muscle growth of 10.0%, compared to 6.8% for concentric training. The difference favored eccentric work, though the gap wasn’t quite large enough to reach statistical significance.
Part of the explanation lies in how your nervous system responds. During eccentric contractions, your brain adjusts its recruitment strategy. Research on the biceps showed a roughly 40% drop in motor unit recruitment thresholds after eccentric exercise, meaning more muscle fibers activated at the same relative effort level. Minimum firing rates also increased by about 11%. In practical terms, eccentric training teaches your nervous system to engage more of your muscle, including fast-twitch fibers that are harder to recruit during normal lifting.
Lower Energy Cost, Higher Force
One of the most surprising things about eccentric exercise is how metabolically efficient it is. Research using magnetic resonance imaging of cellular energy flow found that the metabolic cost of concentric exercise scaled proportionally with how hard you worked, but eccentric exercise did not. Even as the apparent intensity increased, energy expenditure stayed relatively flat. You’re producing more force while burning less fuel.
This has real implications. If you’re recovering from an injury, managing a chronic condition, or simply looking for a way to build strength without the cardiovascular demands of heavy lifting, eccentric training lets you load your muscles significantly while keeping metabolic stress low.
Muscle Soreness and Recovery
There’s a tradeoff: eccentric exercise is the primary cause of delayed onset muscle soreness (DOMS), that deep ache you feel one to two days after a hard workout. Because your muscles are lengthening under high force, the mechanical stress causes microscopic disruption to muscle fibers. This triggers a cascade of events, including calcium leaking into cells, increased activity of enzymes that break down proteins, and an inflammatory response as your body repairs the damage.
The soreness tends to peak 24 to 72 hours after exercise and comes with reduced strength, some swelling, and limited range of motion. Exercising at lower intensities (around 50% of your max strength) produces significantly less damage than maximal eccentric efforts with the same number of sets and reps. This is important context for beginners: starting lighter and progressing gradually makes eccentric training far more manageable. Once your muscles have adapted to a particular eccentric stimulus, repeating it causes much less soreness, a phenomenon known as the repeated bout effect.
Tendon Strengthening and Rehab
Eccentric exercise has a well-established role in treating tendon injuries, particularly chronic conditions like Achilles tendinopathy and patellar tendinopathy (jumper’s knee). When tendons are loaded eccentrically, the cells within the tendon respond by ramping up collagen production and triggering a remodeling process. Over time, this changes the material properties of the tendon, making it stiffer and more resilient. Some studies have also shown increases in tendon cross-sectional area, particularly near where the tendon attaches to bone.
A common rehabilitation protocol for patellar tendinopathy involves a 12-week program. One well-studied approach uses single-leg squats on a 25-degree decline board: 3 sets of 15 repetitions daily, with weight added progressively as pain allows. An alternative uses a specialized machine for heavier bilateral eccentric loading twice per week. Both approaches produced comparable improvements. During the first six weeks, patients typically stop other sports activities, then gradually reintroduce running and jumping in the second half of the program, keeping pain below 5 on a 10-point scale.
Common Eccentric Exercises
You don’t need special equipment to train eccentrically. Any standard exercise has an eccentric component that you can emphasize by slowing down the lowering phase:
- Squats: Lower yourself over 3 to 5 seconds, then stand up at your normal pace.
- Bench press: Take 5 seconds to lower the bar to your chest before pressing it back up.
- Bicep curls: Curl the weight up normally, then take 3 to 5 seconds to straighten your arm.
- Leg press: Use a slow, controlled descent before pushing the platform away.
- Nordic hamstring curls: Kneel and slowly lower your body toward the ground using your hamstrings to control the descent.
Faster eccentric movements also count. Landing from a jump is a rapid eccentric contraction where your quadriceps, glutes, and calves all work to decelerate your body. Plyometric training relies heavily on this type of eccentric loading.
How to Start Eccentric Training
For beginners (generally anyone who can’t yet squat their body weight), tempo eccentric training is the recommended starting point. This simply means slowing down the lowering phase of exercises you already do. A common prescription is a 5-second eccentric, no pause at the bottom, and a 1-second concentric. So for a squat, you’d take 5 seconds to descend, then stand up in 1 second.
A practical beginner program might look like 3 sets of 8 repetitions at this 5/0/1 tempo for two to three compound exercises, performed twice per week. Back squats and bench press are straightforward choices. You can add a rowing movement or other exercises as you become comfortable with the tempo. Using a metronome or counting in your head helps keep the pace consistent.
Because eccentric exercise produces more muscle damage per rep than regular lifting, start with lighter weights than you’d normally use. Expect notable soreness after your first few sessions. As your muscles and tendons adapt over the first two to three weeks, you can begin increasing load. The goal is progressive overload: gradually adding weight while maintaining that slow, controlled lowering phase.