Jefferson curls are the best exercise for rugby

Wait, before you grab your dumbbells and start flexing in front of the mirror. We’re not talking about Bicep curls. Not that there’s anything wrong with having massive guns. We’re talking about a popular gymnastic strength movement called the Jefferson Curl. Perhaps the best exercise you’re not doing as part of your strength and conditioning program.

The Jefferson Curl is one of the few exercises that will quickly increase both your flexibility and strength at the same time. It’s an impressive way to train grip strength, core strength, and hamstring flexibility all with a low-weight single bar movement!

Don’t believe us? Read on and find out why Jefferson curls are the best exercise most rugby players have probably never heard of.

What a Jefferson Curl is

We first discovered this exercise through the gymnastic bodies fundamentals program. Developed by Team USA Gymnastics’ Coach Sommer, who is world-renowned for developing the some of the strongest athletes in International gymnastics competition. If you’re looking for an alternative to lifting weights in the gym, their beginners series might be worth checking out. Note: we have no affiliation with them and don’t get any kind of incentive if you use their programs.

The Jefferson Curl is a slow, weighted movement done at low weights designed to increase flexibility in the lower back. It was originally used by powerlifters after workouts to help them become more limber after heavy squatting sessions which tend to tighten the supporting muscles in your posterior chain. Powerlifters and weightlifters, much like rugby players often suffer from hyperextension in their lower backs from all that heavy squatting. The Jefferson curl helps to balance out the spine by stretching supporting muscles in and around the lower back.

At this point, we encourage you to exercise caution. The Jefferson curl is an advanced movement that needs to be trained at very low weights to start with. Do not throw 135 on the bar and jump straight into it. We suggest your first Jefferson curl session should use no more than 5lbs of weight. And before you scoff, try it and see how hard even just 5lbs is. When performing the Jefferson Curl, there should be absolutely no pain in any of your joints or your lower back. If you feel any pain whatsoever, stop. We advocate a conservative approach to injury prevention.

Being cautious is the best way to prevent training injuries which can prevent progress on a specific movement. Case in point, one of our sponsored athletes suffered a training injury last week (not his fault!) which is going to keep him out of the weight room for 4-6 weeks. At this point in the pre-season schedule, a training injury has the potential to ruin your entire season due to a lack of physical preparedness. When in doubt, err on the side of caution and lower the weight you’re working with. You can’t get stronger when you’re injured.

Benefits of the Jefferson Curl

Posterior Chain

Rugby players have been known to lift a lot of weights in the gym. However, most of us have probably been performing strength based movements without paying much attention to our range of motion, mobility, and flexibility. One thing I noticed when I started gymnastic strength training was that my shoulder flexibility was much worse than I could have imagined. A simple test of shoulder stability is the crab position. Start from a laying position on your back, bring your knees up and feet under your butt. Place your hands next to your shoulders with your hands facing forwards.

Now, lift your torso so that your knees and shoulders are at 90 degrees to the ground. See image below. How long can you hold that position for? Not long, right? While at first, we might imagine that this is an issue with core strength, the much more likely reason is that you simply don’t have the shoulder flexibility to get into this pose.

In the above example, years of incline bench, dumbell flies and pushups have caused significant tightness in the chest and anterior deltoids which restrict the range of motion necessary to establish the crab position. But this happens in a series of another area of the body as well. Not least of which is the severe pressure rugby players place on their lower back through years of heavy squats and deadlifts without any focus on stretching out the posterior chain. The result is a tight lower back, tight hamstrings and a short range of motion that probably prevents you even touching your toes.

The Jefferson curl is an excellent way to loosen your entire posterior chain using a weighted stretch. Improving flexibility without weights is actually quite demanding both physically and mentally. You need to push through your pain barrier to see regular and periodic gains. The advantage of the J-Curl is that gravity will be doing the work for you. The long, slow movement stretches the vertebrae and provides gentle pressure (depending on the weight you use) without putting extreme tension on the lower back.

Core Strength

Core work is the worst. If you’re one of the few people that have a dedicated “core day,” more credit to you. I dare say you are part of a tiny minority of rugby players. Core strength isn’t paid anywhere near the attention it should be. Yet rugby players use their core as much or more than any athletes during competition. Here are just a few things on the rugby field that engage the core, scrummaging, passing, kicking, offloading, catching and lifting in lineouts. That’s pretty universal. Every rugby player can benefit from increasing their core strength. For more on this, try our core strength for rugby players demo. 

Yet as soon as I use that phrase “core strength” – what does your brain immediately jump to? Sit ups and planks, right? While both those movements may well be important, they don’t focus attention on your lower back or obliques which are arguably more important muscle groups for both core strength and rugby performance.

The Jefferson Curl forces you to work your obliques and lower back both during flexion and extension. As you curl forwards (flexion), you’re actually performing a decline curl as you resist the pull of the weight in your hands. As you stand back up (extension), you’re overcoming the weight with each vertebra through the movement. In this way, the J-Curl is working both anatomic motions under light pressure. If we accept that time under tension is actually more important for building strength than are sets or reps, the Jefferson Curl provides has the potential to dramatically increase your core strength without needing to do a single plank for time.

Grip Strength

Rugby players come from many different backgrounds. While some will spend all day laying bricks and developing serious hand and grip strength in the process, others (yours truly) will spend their days typing and sitting at a desk. While this is bad for your hamstrings, it also does nothing to help you build up strong hands and forearms. While this probably doesn’t sound hugely important, having a good grip is essential in many aspects of rugby. You’ll need to grip your mate’s jersey in a scrum, an opponent’s body in a tackle or ruck and the ball when you’re in possession. The stronger your grip, the easier this will be.

While it is primarily a movement that promotes flexibility in the posterior chain, the J-Curl will also give you grip strength benefits. This will depend a little bit on your limiting factors and your programming. But let’s say you’re doing 3 Jefferson curls in each set. If each J-Curl takes around 10 seconds with a 5-second pause, this will give you somewhere near 40 seconds of time under tension. Not for your lower back, but for your hands and forearms. There’s a huge difference between holding a weight from above or holding a weight from below.

During a bench press, you resist the weight from below the bar which means your hands don’t need to work nearly as hard as during a bent-over-row where your body is above the bar. The same principle applies to the J-Curl. Even though the weight is fairly light, spending 40 seconds under tension can be brutal on your hands and forearms. Especially if you’re super-setting with pull-ups (program below), this can cause your grip to blow up quickly.

Hamstring Flexibility

A report published by the English Rugby Union in 2014 found that:

“Hamstring injuries remain the most common and highest risk training injury across the study period.”

The same injury surveillance report also found that “Hamstring injury incidence in matches reduced by around 50% in 2013-14 from the previous three seasons, which might reflect a focused injury reduction effort in clubs… While it was commented earlier that the profile of hamstring injuries in training has remained similar.” 

So what does this mean for amateur rugby players? It suggests that we have a greater chance of injuring or of re-injuring our hamstrings than any other body part when we go to rugby training. This is very likely because our hamstrings are simultaneously too tight and too weak to put up with the stress we put them through on Tuesdays and Thursdays.

If hamstring flexibility is the question, the J-Curl is the answer. The movement places light, very tolerable pressure on the back of the leg and forces it to stretch under tension. Stretching isn’t fun, and that’s probably why so few of us do it routinely. But by doing a few sets of Jefferson Curls at the end of each leg session, you can simultaneously stretch your hamstrings, increase your grip strength, lengthen your back and do it all while making your core stronger. It’s basically a way to do all the exercises you hate and deliberately avoid in one genuinely enjoyable movement.



How to Jefferson Curl

The starting position requires an elevated surface. This can be a bench, box or aerobics step. In our video, the subject is using an upside-down milk crate. So really anything is going to work. Stand perfectly upright holding your kettlebell, barbell or dumbbells in front of your boy with both hands. Lock your legs straight. Some tutorials will tell you to have your feet exactly together. We’ve found that most rugby players probably don’t have the hip flexibility to do a Jefferson Curl in this foot position. So for your first few reps, sets or sessions, place your feet around shoulder width apart and move them in slowly as you progress.

Here’s how a set of 3 should look

Begin the decline of the curl by tucking your chin into your chest and rounding your back one vertebrae at a time from top to bottom. Go slow! There’s absolutely no rush here. Rather than feeling like you’re pushing forward, you should focus on the weight “pulling” your body weight down towards your feet. This sensation probably isn’t something you’re used to, but it will become more natural over time. Keep your body weight forward over the balls of your feet. There is a tendency to lean backward the lower you get. But doing this will actually reduce the stretch in the hamstrings.

When you approach the bottom of the curl, your spine should have a consistent curve through its entire length. If you’re finding that there’s a “flat” part of your back at the bottom of the curl, try pushing your belly button towards your spine. We like to practice getting your chest onto your quads. This will also eliminate flat points in the spine and provides a tangible touch point. Keep your legs locked. The only way to go lower is by allowing the weight to stretch your vertebrae and hamstrings.

Coming up to standing again is simply a reversal of the original movement. Begin the standing motion by articulating the spine one vertebrae at a time. Start with the lower back, then the mid back and finally the upper back. As you’re coming up, there will be a tendency to look up by lifting your chin off your chest. Avoid this. This should be the last thing that happens in the movement, right at the top as you’re straightening your back. As you stand tall, you may feel light-headed. If this feeling is overwhelming, get down from your elevated position and recover before starting again. You should feel a stretch in your hamstrings, glutes, lumbar fascia, and even low traps. You should NOT feel pain in your lower back.

Programming Jefferson Curls

After about 6 months of experimenting with body-weight training, we’ve determined that there are three really good ways to incorporate Jefferson Curls into a rugby-focused strength and conditioning program.

There are 3 times we suggest you do Jefferson Curls.

1. At the end of leg day

This is a technique used by powerlifters to ensure they stay limber after heavy squat and clean sessions. The idea is that after you’ve put a huge amount of pressure on your lower back in a squat position, you need to loosen everything up using a weighted stretch.

If you’ve lifted heavy using our rugby leg workout or a similar strength/power program, you’re probably not going to want to do 30 sets of J-Curls. But 4-5 is probably more than enough.

We suggest following this short program of J-Curls at the end of your leg session:

  • 0:00 mins
    • 3 J-Curls
    • 10 side-leg squats
    • rest
  • 3:00 mins
    • 3 J-Curls
    • 10 side-leg squats
    • rest

Doing 5 sets in this fashion will add 15 mins to your leg day but will also dramatically improve your lower-back and hamstring flexibility which are limiting factors in developing lower body strength and power.

2. Super-setted with Pullups

The worst and most awesome strength training session ever is a 1-hour marathon of super-setted pullups and J-Curls. This session falls right in line with our thinking on prioritizing strength over bulk. Start with sets of 2. Do 2 pullups immediately followed by 2 slow Jefferson Curls at a low weight. Start a new set of pullups every 3 mins.

So the workout looks like this:

  • 0:00 mins
    • 2 pullups
    • 2 J-Curls
    • rest
  • 3:00 mins
    • 2 pullups
    • 2 J-curls 
    • rest

And so on and so forth. As you improve, your aim should be to get to 4 pullups and 4 J-curls every 2 mins. Depending on your body weight, getting to this point will likely take you around 4-6 months to achieve. So be patient, because this doesn’t happen overnight and doing 30 sets of pullups is enough by itself without adding the J-Curl. Remember, if you feel any pain at all in your lower back, stop immediately. There’s no point getting injured in your 26th set of pullups and not being able to train for the next 3 weeks.

3. Before rugby training

Remember we talked earlier about hamstring strains being the #1 injury sustained during rugby training? Well, the J-Curl might well be an answer to this soft-tissue epidemic. If you have a set of bleachers, a big tire or even a low bench at your rugby club or training grounds, we suggest doing 5 sets of 3 Jefferson Curls in the 10 minutes before rugby training. This should only take you 10 minutes. 40 seconds for each set, 80 seconds of rest between sets. That’s a perfect 1:2 ratio of work to rest. 10 minutes people! Can’t you spare 10 minutes to prevent recurrent hamstring injuries? Please.

20-1-20 PROGRAM


A Note on Limiting Factors

After doing Jefferson Curls for about 4 months, there are a couple of things you should know about them and some things to watch out for in your training. Particularly as it pertains to limiting factors. Because the Jefferson Curl involves such a large range of motion (a range of motion you’re always working to increase as well), you’re going to find various different sticking points beyond which you can’t quickly progress. For example, your mid-back. As a rugby player who has done plenty of deadlifts and pullups, I thought I’d be just fine with moving up weights fairly quickly. I found that my progression was limited mostly by the strength of my mid-back.

As you stand up from the bottom of the curl, you’re shifting the pressure from your lower back to your upper-back. I was able to get off the bottom of the curl fine and stand up tall fine, but the part in the middle was rough. For anyone over 6 feet tall, I suspect this is going to be a limiting factor for you too. So if you feel good when you’re standing up tall holding the weight, I suggest going down 5lbs or more. The middle of the curl is deceptively tough, especially when you’re just starting out. Err on the side of caution and go light with your weight. 

The second limiting factor is likely to be your grip strength. If you work in a blue collar industry, you might find this isn’t a problem. But for those of us who sit at desks and lift little more than a business card or a coffee through the day, you’re likely to find your grips give way before your core strength. For this reason, I wouldn’t suggest super-setting J-Curls with any other bent over movement like a bent-over row or a single arm dumbbell row. 

Finally, Hamstrings. Hamstring flexibility, or a lack thereof, is going to be one thing that prevents you from progressing quickly with the J-Curl. Don’t get discouraged. You’ll find that progression goes in stages. You won’t notice any improvement for three weeks and then all of a sudden something will click and you’ll add a couple inches to your range of motion. Stick with it for the first month and you’ll be amazed at the change.  


The Jefferson Curl is a fantastic exercise to stretch and strengthen your entire posterior chain. Always error on the side of caution, and begin this exercise with light weights or no weight at all. Focus on articulating your spine one vertebrae at a time when performing Jefferson Curls. Measure your progress in this movement in terms of months, not days or weeks.




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Training Team

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