Tuesday, March 2, 2010

Core Strength

About a year ago I posted a blog on this same topic. It's a topic I have given lots of thought to recently and so decided to return to it again. I'm still learning what the impact of poor core strength on cycling and swimming may be and so would appreciate any insights from readers.

We read a lot about core strength training any more, but I’ve found most people really don’t know what it means. Most seem to think it means strong stomach muscles. It goes well beyond that. Core strength could be called “torso” strength. It has to do with small and big muscles from your armpits to your groin. These core muscles stabilize the spine, support the shoulders and hips, drive the arms and legs and transfer force between the arms and legs. It’s very much akin to the foundation of a house.

When a triathlete has poor core strength it may show up in several ways. It’s most obvious in running. Poor core strength is evident in a dropping hip on the side of the recovery leg with the support-leg knee collapsing inward regardless of what the foot may be doing. Especially in running, injury is common when core strength is inadequate.

In the two sets of screen shots here you can see two athletes on treadmills running barefoot (click to expand the pictures). Notice first of all the waistline of the shorts of each runner. It indicates what the hips are doing. You’ll see that the woman’s left hip is dropping quite a bit while the man’s stays quite level to running surface. Also note the woman’s slightly collapsing right knee. The man’s is very stable. But the big surprise is their right feet. The woman’s foot has very little pronation and would be considered a stable foot. The man’s is excessively pronated (see the third screen shot).

This is backwards from what we have always been taught to believe about the foot and what happens up the chain. Excessive pronation is supposed to cause unstable knees and hips. Stable feet should not result in hip drop and medial knee wobble. The difference is core strength. The woman’s is poor and so even her feet can’t help. The man’s core is strong and overcomes a foot that would normally cause all sorts of injury problems. And in this case the man is known to have no history of injuries and is an accomplished marathoner. The woman, despite her excellent foot stability, has experienced illiotibial band injuries. Core strength is the difference. The man has it; the woman doesn’t.

For swimming and cycling it is less obvious. Poor core strength in swimming may result in “fishtailing” – the legs and hips wiggle from to side as the hand and arm “catch” is made. Sometimes this is due to faulty stroke mechanics, so it’s hard to differentiate. But poor stroke mechanics may even result from poor core strength in thi case.

In cycling poor core strength can show up as a side-to-side rocking of the shoulders and spine when the pedal is pushed down, even when the saddle is the right height and the rider is not excessively mashing the pedals. This is generally most evident when climbing seated.

There is little doubt, even if it’s not always obvious, that poor core strength results in a loss of power in all three sports.

How do you know if your core strength is adequate? One way is to have a physical therapist do a physical assessment. Find one who works with endurance athletes and tell him or her that you would like a head-to-toe exam to pinpoint weaknesses and imbalances that could reduce performance or lead to injury. And also find out what is recommended to correct any problems found. These fixes may be strengthening exercises, flexibility exercises or postural improvement. This is perhaps the best way of finding out, but there is a cost. The exam generally takes about an hour. I have each of the athletes I coach do this every winter. It’s provides a great start on core strength training.

While quite a bit less effective, another way is to have someone video tape you while running looking for the dropping recovery-side hip shown above. You’re likely to miss the details as for the untrained eye there appears to be little difference in techniques even when the movement faults are gross. Use a treadmill and shoot the video from the back. Tuck your shirt in so you can watch the waistband of your running shorts on the video to see if it dips when the recovery leg swings through. And check the knee of the support leg to see if it is buckling in slightly. You will probably have to view this in slow motion several times to see the unwanted movements if there are any.

If you go the self-help route and determine that you need to improve core strength I’d recommend picking up Core Performance Endurance by Mark Verstegen. This is one of the best books I’ve found on core strength training for endurance athletes.

Special thanks to Mark Saunders, physiotherapist and Director of Physio4Life in Putney, UK, for the pictures and introduction to this concept.



At March 2, 2010 10:25 PM , Blogger Sean in DC said...

Hi Joe. I've been thinking about this topic a lot lately so your advice is quite timely. I often read about accomplished triathletes doing lots of "core work," but without ever getting into any specifics. It's my perception that the average athlete (myself included) is over-saturated with various core exercise information to the point where we can no longer distinguish between helpful, hurtful and just plain weird. I think I could almost simulate 100 different ways to work my abs, obliques and lower back. And we all see those people at the gym doing hundreds of straight crunches.

With that in mind, I've been trying to assemble a smarter regiment of core exercises that maximizes payoff while stripping away unnecessary or redundant actions. My definite favorites include planks, side planks, flutter-kicks/leg raises and a superman position where I alternate leg/arm raise + holds. Other than those, I'm never sure if I'm doing something productive or just spinning my tires.

During racing season, I really just want my core to be one of my assets and not a liability or excuse. Great post Joe and thanks for the very helpful insight.

At March 3, 2010 1:41 AM , Anonymous Anonymous said...

Excellent post Joe. Unfortunately I know from personal experience how poor core strength affects us all. I'm a cyclist and once I'd come to the conclusion that my position was good it took a lot of research on my own to pinpoint poor core strength as my problem. The hardest part I find is actually doing something about it - time constraints etc. It seems to me that this is one of the least understood and under diagnosed problems in sports generally.
Thanks for the blog by the way - keep up the good work!!

At March 3, 2010 4:03 AM , Blogger Tom said...

I am doing Pilates right now. Good mix between Core Strengh exercises, stretching and relaxation.

At March 3, 2010 7:29 AM , Blogger plum said...

Joe I find this recent resurgence of interest in core strength fascinating.

As a cyclist I think its easy to tell if you have a core strength deficiency. You can simply feel it. You can tell that the prime movers are really working, but you simply don't feel that solid connection between upper and lower body. When you're really digging deep you sense it the most; you feel like you're trying to bridge a total body connection with jello.

I've had lower back issues my entire life, and the cause was unknown until last year, when it was discovered that I had a leg length disparity. My corrective therapy just so happens to be a core regimen.

This year I have been very diligent about core - twice a week, 30 minutes at a time. The difference in my cycling is profound. It's the easiest, biggest bang for buck change I have ever made to my training.

As you mentioned, when most think of core they conjure images of tireless bouts of situps. Even one trip to a personal trainer can set you up with a core program that can be done at home, incorporating a great variety of exercises, using little more than an exercise ball. This will give you a unique workout to address your personal deficiencies.

Not into the personal trainer approach? Crack open this month's issue of Bicycling magazine. They have a pair of very effective core workouts, well illustrated and ready for a half hour of your time.

At March 3, 2010 9:17 AM , Blogger Mark Thompson said...

Thanks for the book recommendation. I’ve recently changed my swim stroke and found if I tie my stroke to my body roll (my core strength) then my shoulders are stressed less and my forward momentum seems greater. However, I didn’t know how to properly strengthen my core, I’m sure the book will really help.

At March 3, 2010 9:26 AM , Blogger Eric Johnson said...

david wardon, one of joe's TB coaches, covered part of this topic recently on tri-talk.

here's a good series of exercises for weak glute medius that david referenced in the podcast.


the glute medius is a big contributor to IT band and medial knee pain.

i love how joe's posts always seem to precede or coincide with new information i'm finding in my own reading! thanks joe.

At March 3, 2010 2:11 PM , Anonymous Jan said...

I've always thought that in cycling poor core strength means resting (some part of) your torso weight on your hands. Or am I completely wrong?

At March 3, 2010 8:21 PM , Anonymous Bill G said...

Thanks for the post Joe! In my experiences as a triathlete and now also a coach, I have found proper "core" strength training to be indispensable. Surprisingly, I have found it has helped most in the water. (Maybe because the biggest gains were available there.) Specifically, as a previous post pointed out, a strong core will help a swimmer lengthen the stroke by driving it forward all the way from the hip through the shoulder to the hand as the swimmer rolls. A strong core make this complicated movement more powerful and stable. In effect, you can reach out farther and grab more water. On the bike, the benefits seem have been well described.

I think of it strategically the way you have described strength training gains - as a way to have more in the tank late in a race, by increasing efficiency of movement and thereby enhance endurance. Injury prevention most likely goes up also. In the season, I try to find race/sport specific ways to do "core" work.

Off do to some planks...

At March 4, 2010 2:20 AM , Anonymous Nick de Meyer said...

As a Personal trainer and core strength specialist, i see a lot of triathletes and endurance athletes with weak core muscles, and more importantly those who don't know how to activate their deep stabilising muscles, even after doing a pilates class, (ie, transverse abdominus, multifidus, internal obliques, and pelvic floor muscles). Most people can activate and strengthen their "outer unit" muscles with side planks, front planks etc, but this is not necessarily what is going to improve their core strength. Its the deeper muscles that athletes need to work on, and will only learn in a 1-2-1 session.
I take a client from floor based core stability exercises, to activate these deep core muscles, then progress them onto the swiss ball for core strength, and then onto the TRX Suspension system, where your core muscles (inner and outer unit) work with every movement. All are working with posture and to achieve good biomechanics in the joints from being in the correct anatomical position.
I also use a BOSU a lot for building ankle and lower limb stability and strength, and for core strength for the upper body, plus a number of pre habilitation exercises for the shoulder and injury prone sites for endurance athletes on the "stabilising muscles" which support your joints, effectively helping you to produce more power when swimming, cycling and running, and subsequently less lactic acid. Try and cycle on the computrainer Spinscan holding efficiency at 90% for a minute at a time and you will know what i mean...

There was a recent article in Triathlete about core strength, with a mention for Chrissie Wellington's core strength and posture, which would be due in no small part to her work with Mark Saunders @ Physio 4 life in Putney.

There was a Report by Andrew Hamilton in Peak Performance 224 "cycling special" on how Torso stabilisation increases
cycling efficiency, summarised below:

In cycling exercise studies that have been used to evaluate
muscle metabolism and energy output, it has always been
assumed that any metabolic changes are due to the muscles
actually involved in cycling. But new research conducted by US
scientists at the University of Utah has thrown this assumption
into doubt.
The goal of this study was to determine whether a torso
stabilisation device would reduce the metabolic cost of producing
cycling power – ie increase cycling efficiency and lower energy
expenditure for the same cycling power output.
Nine male cyclists cycled on a Velotron cycle ergometer at
power outputs that produced 50, 75, and 100% of their
ventilatory thresholds (the exercise intensity that produces a
sudden jump in breathing rate). Three different pedal cadences
were used: 40rpm, 60rpm and 80rpm. Each cyclist was tested
with and without torso stabilisation (a device to limit movement
in the torso when pedalling).
The metabolic costs of these different intensities and pedalling
cadences measured with and without the stabilisation device
showed that not only did torso stabilisation reduce the metabolic
cost of producing sub-maximal cycling power (ie increase cycling
efficiency) but that this reduction was also related to pedalling
cadence. The overall reduction in metabolic cost was around 1%,
with the greatest reductions at lower pedalling rates where
pedalling force was greatest (-1.6% at 40rpm, -1.2% at 60rpm,
-0.2% at 80rpm).
The researchers concluded that ‘muscular contractions
associated with torso stabilisation elicit significant metabolic
costs, which tend to be greatest at low pedalling rates’. The
implications of this study are potentially significant for cyclists.
Not only does high cadence pedalling appear to increase
efficiency by reducing the amount of energy required to stabilise
the upper body when cycling, but there’s also the possibility that
cyclists with efficient torso stabilising muscles (ie greater core
stability) may have an energetic advantage over those with weak
stabilising muscles.
Can J Appl Physiol Aug 2005; 30(4):433-41

At March 4, 2010 7:58 AM , Anonymous Anonymous said...

In my view, the best core book available is Joanne Elphinston's Stability, Sport and Performance Movement. I also have Verstegen's book, but Elphinston does a much better job of explaining why you need to increase functional stability. After detailed explanations comes a comprehensive chapter on self-assessment, followed by a number of chapters with different levels of exercises.

At March 5, 2010 3:32 AM , OpenID Iano said...

Hi Joe

Thank you for an interesting blog. I really am enjoying your your articles, which are so topical!.

I've been encorporating core workouts into my gym sessions for a number of years now, but have been strugggling with the time required to do a full proper session.

I've had to cut back my triathlon activities the last few years due to a growing family and time commitments, so have only really been focusing on running and in particular the Comrades Marathon. Last year I din not have an ideal race. This year I've decided to work only on my core and not overall body fitness.

Bobby McGee has a great core workout session that takes about 15 mins in his "Running Essentials" booklet and I have been following that, with some work on the Powerplate (I'd be interested to hear your thoughts on the effectiveness of Powerplates).

I have also just started reading Danny Dreyer's book, Chi Running http://www.chirunning.com/ which emphasises the core as the most important muscle.

It appears to be working, as on Wednesday, I had a breakthrough run where I ran way above my abilities and managed to keep up with the "big dogs".

Time will tell.

Thanks for the great articles - keep them coming.


At March 5, 2010 11:03 AM , Anonymous Marshall Hance said...

I'm surprised the extent to which you are prescribing to the core strength kool-aid given your platform on specificity. You've done well resisting the electrolyte mythology; why this?




At March 5, 2010 12:01 PM , Blogger Fortunateson said...

I had a gait analysis done by a physical therapy group. Looked pretty much like your video. I started by working on hip flexors and that helped allot. Also a good water areobics class is good core toning

At March 22, 2010 5:42 PM , Blogger Neeraj Engineer said...

Building core strength was one huge factor that helped me with improving performance and still staying injury free while running and cycling. I followed the "inner unit" stuff recomended by coachr.org.
Any thoughts on that?

What surprised me the most was that not a lot people talk about core strength and it's importance for running and cycling.

Btw, the other factor that helped with running was "Evolution running". thanks


At March 24, 2010 7:46 PM , Anonymous Ed said...

Expanding a bit on the nice comments about inner unit and outer unit: it is important to understand that movement occurs in the context of stabilization. If you want to lift something with your arm, muscles of the rotator cuff first stabilize the shoulder (scapula/humerus), and other muscles stabilize the scap on the shoulder. In this context, the arm moves, gaining strength from its firm, stabilized base. Stabilization of the torso (lumbopelvic hip complex) gives a base for leg is another example. The local muscle system provides the stabilization while the global provides movement.

I think the essence of a core training program is the general absence of movement of the targeted stabilizers. Other things might move, though, for example, engaging abdominal stabilizers that hold the hip/torso stable while moving a leg. You may have seen the "wood chopper" exercise. Do it with a moving torso and it is a strengthening exercise for the torso but not much good for stabilization. Do it again with no torso movement but only arm movement and it becomes more effective as core development. This is just saying, 1) training is specific 2) performance is more than strength, it is strength plus skill (control) and for you to develop the stabilization that Joe illustrates in the runner or the stabilization mentioned in the article, you need to practice the skill of stabilization of the appropriate structures. That's why crunches don't help you (amongst other reasons). I'd argue that hip hikes also aren't the right thing- that's movement and strength. Instead, learn to stabilize the pelvis lying supine on the floor doing a simple marching movement (one foot lifts, knee bent, small distance), then two feet, then one foot but leg straight, etc. Somewhere along the way, try standing, engaging core to stabilize pelvis, then bending one knee so you're standing on one foot, hip at 90, knee at 90. When you can do that without hips wagging around, progress to staying on one foot and then extending at the knee, flex knee back to 90, extend, etc. (so reps are done continuously standing on one foot). Compare this with the hip hike. That's strength while this standing exercise (part of D'ROM from Bob Gajda many years ago) is stabilization (and active development of hamstring range of motion).

Sorry this got long...wanted to give what, in my opinion, is a metric you can use in selecting exercises so that you get the core training (stabilization) that you need. You'll come to see that core training is present in every movement you make IF you put your mind in it and pay attention to the stabilization portion of the movement.

At April 2, 2010 11:24 AM , Anonymous Core Cambridge said...

Thanks for the good read and training tips. I've also taken a few Pilates classes in Cambridge to supplement my core strength and even focus on specific running muscle groups.


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