Rate of Force Development: What It Is and Why You Should Care

No, sorry, this is not a post on how to become a Jedi by increasing your rate of using the Force. Shucks.

The Rate of Force Development (RFD) we're going to talk about is that of muscles and is *kinda* important (read: essential to athletic performance). Today's post will enlighten you as to what RFD is and why one should pay attention to it. Next post will be how to train to increase RFD. So grab something delightful to munch on (preferably something that enhances brain function, like berries.) Caveat: There is a lot of information and other stuff that I’m not putting into this post, sorry, this is just a basic overview of why RFD is important for everyone.

What is RFD?

It is a measurement of how quickly one can reach peak levels of force output. Or to put it another way, it’s the time it takes a muscle(s) to produce maximum amount of force.

For example, a successful shot put throw results when the shot putter can exert the most force, preferably maximal, upon the shot in order to launch it as far as humanly possible. She has a window of less than a second to produce that high force from when she initiates the push to when it's released from her hand. Therefore, it is imperative that the shot putter possess a high rate of force development.

Where does RFD come from?

motor unit

Well, let me introduce you to a little somethin’ called a motor unit. Motor units (MU) are a motor neuron (the nerve from your brain) and all the muscle fibers it enervates. It can be anywhere from a 1:10 (neuron:fiber) ratio for say eyeball muscles, which have to produce very fine, accurate movements. Or 1:100 ratio of say a quad muscle which produce large, global movements.

There are two main types of MUs: low threshold and high threshold. The low threshold units produce less force per stimulus than the high units. For example, a low unit would be found in the postural muscles as they are always “on” producing low levels of force to maintain posture.  A high unit would be in the glutes, to produce enough force to swing a heavy bell or a baseball bat (even though the bat is light, the batter has to move that thing supa fast in order to smack a home run).

Also note the different stimuli required for the different units: small posture adjustments vs. a powerful hip movement. A low stimulus activates low threshold units and a high stimulus activates the high units.

Now, MUs are not exclusively low or high; MUs throughout the body are more like a ladder, low MUS at the bottom, with each successive rung being a higher threshold MU than the one below. And, like a ladder, you can just all of the sudden find yourself at the top of the ladder without having to climb the lower rungs. Unless of course, you’re a cat:

High MUs rarely (if ever) activate without the lower MUs activating first. So, the rate of force development is dependent upon how quickly the lower rungs of the MU ladder can be turned on to reach the highest threshold units (which produce the most force per contraction)… Not only that, but all those units working together produce more force than just the higher ones by themselves, so it's a good thing that the lower ones must activate too. The muscular force produced is the sum of all the motor units.

Why Care About RFD?

Since those higher threshold units won’t be active until the lower ones are on, force production will remain low until the higher ones can get their rears in gear, therefore, going up the MU ladder faster will result in more force produced sooner in any sort of movement.

Let’s take the example of two lifters, A and B. Both are capable of producing enough force to deadlift 400lbs. However, lifter A has a higher RFD than lifter B. Lifter A can produce enough force to get the bar off the ground in about 2 seconds and lock out (complete the lift) in about 3-4 seconds. Lifter B takes 3 seconds to get the bar off the floor and another 5 to get it near his knees. For those who don't know, a deadlift should be roughly 4-5 seconds TOTAL (typically, most people's muscles give out around then if the lift hasn't been completed). B-Man is going to fail the lift before he gets that bar to lock out and will hate deadlifting forever. Bummer.

Or, utilizing a Harry Potter for my analogy for this post, it is analogous to the rate of spell development; how quickly and how powerfully a wizard's spell is performed. In a duel, the faster and more forceful wizard will win. For example, when Professor Snape totally pwns Gilderoy Lockhart:

Hence, if one wants to get stronger, increasing the rate of force development is essential! Moving heavy weights is good (and high RFD helps with that as we saw with Lifters A and B from above); moving heavy weights FAST is even better when it comes to stimulating protein synthesis aka: muscle building. Possessing a high RFD is vital in order to move those bad boys quickly.

Next post, we’ll delve into training methods that can help increase the RFD so you won’t be these guys and skip deadlifting because your rate of force development is less than stellar…

Off-Season Training: Overhead Athletes

kiss

Last week, we laid out some general guidelines for athletes heading into their off-seasons. You should read it, if you haven't already. Today, we'll delve into some specifics for overhead athletes (i.e. baseball, softball, javelin, shot put, swimmers (though it seems as if they never have an off-season), etc.). Shoulders are rather complicated and annoyingly fickle joints that can develop irritation easily which is why proper attention MUST be paid to shoulder mechanics and care during the off-season. There is nothing "natural" about throwing a heavy object (or a light one really, really fast) and shoulders can get all kinds of whacky over a long, repetitive season. I'm going to keep it sweet and simple.

1. Restore lost mobility and improve stability

- Hips: they get locked up, especially on athletes that travel a lot during the season (helloooo long bus rides). Restoring mobility will go a long way in preventing hip impingements, angry knees, and allow for freer movements in general. Locked up hips will prevent safe, powerful throws and batting, thus, now is the time, Padawans, to regain what was lost!

- Lats: Usually tighten up on the throwing side and create a lovely posture that flares the rib cage and makes breathing not-so-efficient. Loosen up these bad boys!

- Breathing patterns: Those need to be re-trained (or trained for the first time), too. Breathing affects EVERYTHING. Learning proper breathing mechanics will do a lot to restore mobility (T-spine, shoulder, and hips), increase stability (lower back and abdominal cavity), and create a more efficient athlete (more oxygen with less energy expended to get it). I've written about it before HERE.

- Pecs and biceps: These guys are gunky and fibrotic and nasty. Self-myofacial release is good, finding a good manual therapist would be even better, to help knead that junk out! One caveat: make sure that as you release these two bad boys, you also add stability back into the shoulder. This means activating lower and mid-traps and the rotator cuff muscles to retrain them to work well again. Why? Most likely, the pecs and biceps are doing a LOT of stabilization of the shoulder (which they shouldn't be doing so much) so if you take that away through releasing them, one of two things will happen: 1) injury will occur since there's nothing holding stuff in place, 2) no injury, but the pec and/or bicep will tighten right back up again as your body's way of producing stability. So, mobilize then stabilize!

2. Improve scapula movement and stability

Along the lines of restoring mobility everywhere, the scapula need particular attention in overhead athletes as they are responsible for pain-free, overhead movements. Below is a handy-dandy chart for understanding scapula movements:

shoulder-scapular-motions

Now, over the course of the season, an overhead athlete will often get stuck in downward rotation therefore at in the early off-season (and throughout really) we want to focus on upward rotation of the scapula. Exercises like forearm wallslides are fantastic for this.

Eric Cressey notes that the scapula stabilizers often fatigue more quickly than the rotator cuff muscles. This means the scapula doesn't glide how it should on the rib cage, which leads to a mechanical disadvantage for the rotator cuff muscles, which leads to impingements/pain/unstable shoulders.

We need a freely gliding scapula to get overhead pain-free.

As we increase the upward rotation exercises, we want to limit exercises that will pull the athlete back into downward rotation, i.e. holding heavy dumbbells at their sides, farmer walks with the weight at sides, even deadlifts.(whoa now, I'm not saying don't deadlift, but limit the volume on the heavy pulls for a few weeks, and like I said in the last post, training speed work will limit the amount of load yanking down on those blades.) Instead, athletes can lunge or farmer carry in the goblet position (aka, one bell at their chest). 

There is more to be said, but let us move on, shall we?

3. Limit med ball work

At SAPT, we back off on aggressive med ball throwing variations for the first couple weeks post season as the athletes have been aggressively rotating all season. Instead, we'll sub in some drills that challenge the vestibular such as single-leg overhead medicine ball taps to the wall. (I don't have a video, sorry.)

Or, stability drills such as this:

If we do give them some low-intensity throws, we'll have them perform one less set on their throwing side than on the non-throwing side.

4. Limit reactive work

We don't usually program a lot of sprint work or jumps the first few weeks. If we do program jumps, we'll mitigate the deceleration component by adding band resistance:

5. Keep intensity on the lower end

As mentioned in the last post, instead of piling on weight, we enjoy utilizing isometric holds, slow negatives, and varying tempos to reap the most benefit from the least amount of weight. We also maintain lower volumes over all with total program.

There you have it! Tips to maximize the off-season and lay a strong, stable foundation for the following season!

Build Muscle: Top 5 MUSTS!

How is it some build muscle with, seemingly, little to no effort? Putting meat on the bones comes easy for some: they’ll do a couple curls and drink a glass of milk then BAM, they’re swole.  For the rest of us, it can feel like we have to grind and suffer day in and day out for an ounce or two of muscle.  The methods used and the advice given can sometimes become overwhelming.

Do this program... “Take these supplements... Eat 22.75 grams of protein every 76 minutes... Train each bodypart once every ten days.”

Sometimes you’ll hear fitness experts give advice that can be contradictory or confusing, or just plain unreasonable for you and your lifestyle.

Amongst the sea of information on the quest for building muscle out there, here are my top five tips for beefing up.

1. Make Strength a Priority

If your goal is purely to build muscle and you couldn’t care less about your deadlift max, that’s great!  Good for you, and to each their own.  However, understand that as you get stronger you can increase the muscle building stimulus by utilizing greater loads.  We know we need time under tension via resistance training to stimulate growth, but if you continue using the same loading schemes over a period of time your body will eventually adapt and the stimulus dies.

How do we avoid this?  Focus on getting stronger!  Have a handful of “indicator lifts” to use to track progress.  These lifts are ideally big compound lifts that you strive to become stronger in.  Personally I use the the biggie compound exercises: back squat, deadlift, bench press, and overhead press to track my progress in strength.  Other good options to use are any squat exercise variation (front, box, goblet), push-ups, pull-ups, single leg movements, row exercise variations, prowler work, or farmer’s walks.  Heck, if your goal is to grow enormous biceps focus on getting stronger at the curl.

The point is we want to look back at our own records after months and years pass and see that we are capable of throwing more weights around.  If you make awesome improvements in strength over a significant length of time I’d be willing to bet that you’ve made progress in your lean body mass as well.

2. Volume

This is where we see a big difference in the typical comparison of how a bodybuilder trains versus how a powerlifter By joining a RED franchise, you could earn in excess of ?1,300 more per year than at other national truck driving schools – and significantly more than if you choose to operate as an independent instructor. trains.  The bodybuilder, whose primary goal is to build muscle, will utilize a ton of volume into their training.  A bodybuilder"s workout for his (or her) chest may do something along the lines of the following:

Bench Press	4x8
DB Incline Press	3x10
DB Flyes	3x12
Pec Deck	3x15

The powerlifter, on the other hand, may work up to a heavy single on the bench, do a few sets of rows and go home.

Now this is a very simplified comparison of the two training disciplines but you get the message: if mass is your goal, you need more volume in your workouts.

More volume, however, does NOT necessarily mean that you have to be lifting in the 10-20 range for each exercise.  If you did that, you’d be sacrificing too much tension to get those reps in.  Try some different set x rep schemes that will allow for significant volume with moderately heavy weight.  7 sets of 4, 5 sets of 5, and 4 sets of 6 are all good options, especially for your “main movement” of the day.

3. Eat Better

This is a problem for a lot of younger athletes that stay very active year-round.  You need food to live, and you need food for energy, but you need even MORE food to build muscle.

Be honest with yourself!  You want to be bigger and stronger but all you had for breakfast was… nothing?!  Re-think that strategy.

The nutritional side of muscle gain is underestimated too often, and it needs to be a consistent effort everday.  If you eat like an infant all week, but binge at a Chinese buffet on Saturday it doesn’t count.  Eat a lot of good food every single day.

Sometimes it’s not an issue of eating enough food, but eating enough of the right foods.  A diet consistent with cookies and cokes probably won’t be the key to building a big strong body that you work so hard for.

Keep a food log and make sure you’re eating right.  If your still confused and overwhelmed, just have Kelsey analyze your diet and she’ll tell you everything you’re doing wrong.

4. Aim for a Horomonal Response

Your hormones are the key to growth.  Without them we’d be nothing.  No need to go into a complex physiology lesson right now, but here are some quick tips you should keep in mind.

Testosterone: Stimulated by lifting heavy weights.  Hit it hard and heavy, and get adequate rest between sets.

Human Growth Hormone: Stimulated by moderate weights, higher volume and lower rest periods.

Cortisol: Evil. Catabolic stress hormone that doesn’t want you to gain muscle.  Keep it low by getting enough sleep and doing whatever helps you de-stress your life.

5. Be Aggressive!

Building muscle takes hard work and focus.  You can’t just casually hit the gym once every couple of weeks and expect huge gains.  Lift and eat with a purpose, and be stubbornly consistent.  If you hit a plateau, change something up and keep grinding.

Make your goal important, and put in the necessary effort it takes to make it happen!