Science Friday: Why You Should Foam Roll Prior to Exercise

Over the last decade foam rolling has gained popularity as a self-myofascial release technique that works on the same principle as massage. Namely that it reduces any restrictions and adhesions between fascial layers (the connective tissue that surrounds muscles, tendons, bones, etc), but instead of a therapist providing the external pressure to the soft tissue, the user simply places their body weight onto a foam roller to exert pressure on their own soft tissue.

Despite the growing popularity there is limited research into the effectiveness of foam rolling. Proponents chiefly use this technique as a way of increasing range of motion (ROM) prior to exercise and/or to improve post-exercise recovery. Increasing ROM prior to exercise is important for athletes as they must be able to attain an optimal position to maximize their ability to safely produce force. After all, if an athlete can’t raise their arms above their head without compensating through hyperextension of the lower back, or internally rotating the shoulder, then how would they expect to safely press maximal weights overhead?

Traditionally static stretching has been used to increase ROM prior to exercise but several studies have shown that static stretching actually reduces the amount of force that an athlete can produce immediately after stretching. The study I want to discuss today entitled, “An acute bout of self-myofascial release increases range of motion without a subsequent decrease in muscle activation or force“, looked at the immediate effects of foam rolling on ROM and force production.

In this study the subjects were split into one group that foam rolled their quads for two 1 minute sessions with 30 seconds between sessions and another control group that performed no foam rolling. Knee joint ROM was measured before and after (2min and 10min) foam rolling and a number of methods were used to measure quad activation and force production. On average the subjects improved their knee ROM by 11 degrees and 9 degrees when measured 2 minutes and 10 minutes after foam rolling respectively. Obviously there was no similar improvement in the control group.

However, the most interesting part of this study was that there was not a significant reduction in quad force production or activation after foam rolling. In other words, subjects got the benefits of static stretching – increased ROM – without the negative side effect of reduced force production. The authors of the study postulate that this is attributed to the physiological differences between how the ROM is improved for static stretching versus foam rolling. The former places pressure at the insertion points of the muscle and may cause tissue damage while the latter reduces the fascial viscosity to a more gel-like state through mechanical stress of the tissue.

Conclusion: Foam rolling is an effective method for increasing joint range of motion prior to exercise without reducing your muscle’s ability to generate force. You should do it more often…

Originally posted by Jeff Pruitt of CrossFit 316

Science Friday: Should I do Strength & Aerobic Training on Different Days?

We’ve previously looked at a study showing concurrent training (i.e. resistance + aerobic training) as being superior to aerobic training alone. This week I’ll review a study that tries to answer which style or protocol of concurrent training is superior. For example, is it better to separate your strength and aerobic training into completely different days or will performing both on the same day give equal or superior results? According to the study entitled “Effects of Concurrent Exercise Protocols on Strength, Aerobic Power, Flexibility and Body Composition”, the answer is “it depends”. In this study the researchers split the participants into two groups:

Concurrent Distinct Endurance-Resistance (CDER) – 2 strength & 2 aerobic sessions each week performed on different days (i.e. 4d/wk)
Concurrent Parallel Endurance-Resistance (CPER) – 2 strength & 2 aerobic sessions with strength & aerobic on the same day (i.e. 2d/wk)

Each group was tested in numerous categories and the results are shown the table below. In nearly every category both groups showed significant improvement from pre to post tests. However the CPER showed better improvement relative to the control group in nearly every measurement except aerobic power and 60m sprint. And the CPER group showed a statistically significant improvement in body fat percentage compared to CDER.

Conclusion: Concurrent strength and aerobic training will improve performance and body composition. Unless you are a competitive track & field athlete looking to do every last thing you can to maximize aerobic power then you should perform your strength and aerobic training on the same day. This same-day approach will yield better strength and overall fitness when compared to doing strength and aerobic training on different days.  This is yet another reason (here are some more) why at CrossFit 316 we do strength AND metabolic conditioning every day…

Originally posted by Jeff Pruitt, owner of CrossFit 316

Aerobic Exercise + Strength Training = Optimum Body Composition Changes

Written and posted April 19, 2013 by Jeff Pruitt, CrossFit 316

There are a lot of women out there that think that aerobic exercise alone will produce the kind of changes in body composition they want to see. Images of bodybuilders and other strength athletes have them worried that lifting weights will make them too big and bulky. The study we’ll look at this week shows that lifting weights alone will not decrease fat mass and that aerobics alone will decrease fat mass but not increase lean body mass – not exactly new science here. However, a combination of the two led to greater increases in fat loss, lean muscle mass and a substantial decrease in waist circumference, and I think those are all things that women and men would be interested in.

The paper is a relatively controversial study entitled “Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults.” I say controversial because some of the conclusions drawn by the authors have sparked debate but are really immaterial to our review – we’ll simply look at the data and draw our own conclusions!

In this trial the authors randomly placed participants into 3 categories:

Resistance Training (RT) – 3 days/wk; 3×8-12 rep scheme
Aerobic Training (AT) – 12 miles/wk @ 65-80% VO2 max
Resistance Training + Aerobic Training (RT/AT) – combination of both of the above

The following chart shows data from each of these 3 categories. The measured data were weight and fat percent change, lean body mass and waist circumference change and thigh muscle area and fat mass change. This chart reminds me of the Verizon “Easy Choice” commercial where the Verizon rep presents a bunch of different charts to a focus group and they laugh because it’s obvious that Verizon is the best choice given the data presented.

It’s pretty obvious here which protocol is better. RT alone adds muscle mass but does very little for losing fat mass. Conversely AT alone produces fat loss but actually causes a loss in lean body mass which is kind of obvious if you look at the body composition of endurance athletes. The AT/RT group excels in every category – essentially it is a combination of the benefits of both types of training as one might expect.

Now the authors, instead of drawing the obvious conclusion that AT/RT is the optimal choice, argue that AT is better if you balance time commitments vs health benefits since AT/RT involves more workout time per week. This conclusion has been debated ad nauseum on the interwebs so I won’t rehash all those arguments but I will say that scientifically one must define and measure “health benefits” before drawing such a conclusion.

The authors failed to mention that despite the time commitment for AT/RT being 3hrs/week more than AT alone, the dropout rate for the AT/RT group was only 23% compared to 34% for the AT. And guess what the #1 reason for AT dropout was? Yup, time commitment, despite the fact that they were exercising significantly less each week than the AT/RT group. Could it be the monotony of AT training was the cause of the higher dropout rate? That would be my hypothesis given my own personal experience and from coaching others.

Conclusion: Weight training combined with resistance training produces superior body composition changes when compared to doing either mode of exercise by itself. Despite more than double the time exercising the dropout rate for those combining weight training with aerobic training is less than those doing only aerobic exercise. Constantly varied works after all – go figure. Get stronger, get more fit, look better – that’s our goal at CrossFit 316 and that’s why we lift weights AND perform aerobic conditioning…

Power is the Path to Fitness by Jeff Pruitt

Written by Jeff Pruitt of CrossFit 316

How many of you try and use the prescribed weight for a workout just to prove to yourself that you can do it? Let me be the first to tell you that prescribed weights suck. They’re fine for competition, or benchmark workouts to see where you rank among thousands of other CrossFitters, but they are definitely sub-optimal for improving your general level of fitness.

How do you pick what weight to use during a workout? For too many people it’s just a random decision and that’s unfortunate because while it may not be rocket science, there is a certain amount of science involved in getting more fit. I’m going to explain how and why to choose the appropriate weight in order to maximize the efficiency of any given workout.

In CrossFit we define fitness as increased work capacity across broad time and modal domains. In plain English that means improving your ability to do more work using different movements in workouts of varying times. And as anyone that has done a CrossFit workout will attest, increased work capacity comes via intensity.

Now the beauty of intensity is that we can measure it. Intensity, as we define it, is just the average power you produce during a given workout. We don’t need to make this overly complicated but just know that in physics average power equals the amount of work done divided by the time taken to do the work.

That means there are two paths to increasing the average power of your workout – the first would be to increase the weight used and the second would be to do the workout faster. Many people choose the first approach because it seems harder or because of some bogus notion of prescribed weights but this is often counterproductive. Many times dropping the weight and doing the workout faster will actually increase your average power and thus improve your fitness faster. The reason is because there is no work being done while you are resting and staring at the bar.

There are formulas that attempt to map the number of reps in a workout to some percentage of your one rep max and that is exactly why you’ll see those percentages show up on the whiteboard for certain workouts. But practically speaking, the weight (or scaling for gymnastics movements) you should use is one that allows you to do the workout unbroken but right on the edge of having to rest.

Now when we do strength work we are looking for a different stimulus and thus we increase the rest periods between lifts, but for metabolic conditioning there is simply no arguing with physics and physics says you need to pick a weight that makes sense in order to maximize your fitness level. So don’t just think about finishing a workout with a prescribed weight; think about maximizing average power by doing the workouts unbroken or with very minimal rest…

This post was originally written for Guerrilla CrossFit by Jeff Pruitt