Marchi et al, 2013 tested the integrity of the blood brain barrier in American football players’ pre and post-game to determine what, if any, changes could be determined. We know that blood brain barrier disruptions are implicated in Alzheimer’s, stroke and multiple sclerosis. One of the primary problems when the barrier is disrupted is the nervous system encounters proteins it has never seen before and literally creates anti-bodies to proteins in your own brain.

Blood was drawn pre game, 1 hour post-game and 24 hours post-game. The blood was tested for S100B, a protein found in astrocytes and for S100AB, the anti-body the body generates when it leaks out of the brain and into the body. Head impact was monitored by video replay and athletes completed a questionnaire about the effects the impact had on their short and long term abilities. Computer cognitive testing was also used to determine any immediate changes in brain behavior and processing.

They showed that even sub-threshold hits resulted in elevation of S100B and S100AB. This is not conclusive evidence that the brain blood barrier is critical in concussion but it demonstrates that the central nervous system can be attacked by the immune system after even minor head impacts. Given the auto-immune considerations in many central nervous conditions- head impacts now become a major concern.

We know from studies in soccer that many sub-threshold hits can accumulate and lead to long-term cognitive deficit. This is another nugget of evidence that head trauma is a major problem. At some point we are going to have a side line saliva test for this but until then, take care of your brain.

Earthing also called grounding, is sleeping with a blanket that is electrically grounded. The idea being that an exchange of electrons occurs between you and the earth.  Users cite our evolutionary heritage where we slept in contact with the Earth for over 95% of our species evolution. Wever, 1970 at the Max Planck Institute recorded that exposing men to different electric fields affected their circadian rhythms. It has been documented by Jeff Spencer, Doctor of Chiropractic Medicine and the medical specialist of the US Tour de France team, that once Earthing blankets were used during competition, not only was sleep improved but tendonitis was reduced and wound healing improved during the race.

This anecdotal evidence was enough to get me to look at what literature was available. Brown, et al 2010 looked at how earthing blankets affected muscle soreness. The authors were clever in that they blinded the study to the subjects- this is relatively unusual in these types of studies because blinding is generally not possible. He had 8 men 20-23 years old with healthy BMI train eccentric heel raises with 33% of bodyweight. 4 subjects slept with grounded blankets and 4 slept with grounded blankets that had wires that did not conduct.

Blood samples, saliva, MRI imaging and pain protocols were all measured. This was repeated 3 times a day for 4 days. Results were quite interesting. 5 of the 6 white blood cells groups dropped by greater than 10%! Blood glucose dropped by 15% and bilirubin decreased by more than 25%! Creatine Kinase dropped by over 86%, aspartate transaminase increased by 17% and saliva cortisol increased by 13%. Blood tests for trace minerals also showed an increase, generally above 10%. Finally, soreness decreased by over 80% post workout. Overall, 30 of the 48 markers measured demonstrated greater than 10% change. If nothing else, this raises some interesting questions.

Cheavlier, et al 2013 found that when 10 subjects wear  a grounding patch on their legs for 2 horus a day they lowered overall blood viscosity by a factor of 2.7. This is not huge but again raises increasing questions. Several other studies have shown cortisol (by saliva and blood) drops significantly within a few days of beginning earthing.

We are not completely sold nor are we indicating that people should buy these but this is an interesting approach to recovery and seems to have sufficient evidence to bear investigation. It should be noted that if it does thin blood, anyone taking blood thinners should present evidence to their doctor before beginning an earthing protocol.

Until now, our way of measuring fatigue has been rate of perceived exertion- basically asking from 1-10 how tired are you? If one were a smarter coach, they would also ask 1-10, how recovered are you from our last session –forcing the athlete to consider the overall training arc.

Michael, et al. 2012 has gone far beyond this. Using 9 recreationally trained cyclists they simulated 10h of activity. Upper body exercise, lower body exercise and cycle ergometery were all performed. Each hour of the study, saliva swabs were taken and analyzed for two peptides. The ratio of these peptides appears to accurately reflect the level of fatigue the athletes were reporting P<.05

The same lab performed another experiment in 2011. Kalns, et al. 2011 completed a survey of participants entering the elite US Air Force tactical air combat controller training pipeline. The training is approx. 20 months long with a failure rate of 80%. The goal of the study was to monitor various physiological and psychological variables to see what could be used to determine successful completion of the course in future classes.

126 candidates had 55 variables collected divided into 5 broad categories; 1- demographic, 2- psychological compositions, 3- physical performance, 4- physical activity questionnaire and 5- salivary biomarkers for fatigue (as the above study did for the cyclists).

Of these 55 variables, 4 variables were found to predict successful completion of the course. Total runtime for a 1.5 mile course, average weekly miles run for the last year, height and the fatigue biomarker index. In fact, the ideal candidate with the greatest chance of passing the program could run 1.5 miles in under 10.4 minutes, ran >8.5 miles/week for at least 1 year, had a biomarker rate of less than 3.5 (or greater than 103 depending on units) and was at least 71 inches tall- they would very likely complete the program.

This particular program was only during the initial indoctrination portion of the training cycle or 13.5 weeks. During that time period 48.3% of applicants failed. If these 4 criteria had been applied to the group beforehand, it was determined that failure rate would have been 23%. Thus this combination can predict half of the failures in the indoctrination part of the program! Given that height is fixed in adulthood, 1.5 mile run time is easily obtainable (particularly in the military), previously run weekly distance is easily checked in training logs and saliva swab analysis is not out of reach of most people- tests of this nature can predict physical and mental resilience and be easily implemented. For those interested, Hyperion Biotechnology is the company who owns the lab where the saliva analysis is done. Should you wish to determine if you are fatigued and what you need to do to recover properly, I’m sure these guys can help.

Gorsuch, et al. 2012 compared Division I college cross country runners. 10 male and 10 female runners performed their 10 rep max for 6 reps in the parallel squat and the partial squat hooked up to an EMG machine. The EMG was hooked up to the rectus femoris (for quad recruitment), biceps femoris (for hamstring recruitment), erector spinae (for back recruitment) and the lateral head of the gastrocnemius (for calf recruitment).

Interestingly, male and female runners displayed a different quad to ham ratio. As discussed previously, high school girls are far more likely to injure their ACLs in the same sports than boys because of their q-angles and the best way to prevent this is to strengthen the hamstring until the quad to ham ratio is 4:3.

Rectus femoris and erector spinae displayed much higher activation in the parallel squat compared to the partial squat while the gastrocnemius and hamstring were stimulated to similar levels. So if you are running uphill or require spinal stabilization during your running, parallel squatting should be used in your training, nor partials.

Brayton, et al. 2012 had 11 strength trained men perform squats at 50-90% of their max load at partial, parallel and full depth. The exercises were performed in a motion analysis laboratory to determine relative muscular effort. It was found that hip flexor activation increased both with load and depth. Knee extensor activation increased with depth but not load and that ankle plantar flexion increased with load but not depth.

Clearly, depth and load have a role to play in squatting and their carry over to sport. Depending on the goals of your current program, adjust appropriately. We would strongly caution though, partial squats lead to partial results- the deeper you go, the more you grow.

Let’s not kid ourselves, sprinting requires tons of energy. It is hard on the nervous systems, on the muscles and joints and taxes the cardiovascular system. The goal of sprinting (if you are not a sprinter) is not to sprint but to improve your ability to play your sport. If it leaves you so fatigued you are unable to do other forms of training- what’s the point?

Farzad, et al; 2011 cut a wrestling team in half. 7 wrestlers performed the normal 3 practices a week, 2 weight training sessions and 1 plyometric session. 8 wrestlers from the same team performed all this and 2 sprint sessions per week.

The sessions were warm-up, then 6x35m with 10 second break. Not a very long workout but very intense.

The wrestlers who had added sprinting demonstrated a decrease in cortisol by 13% and an increase in total testosterone by 19%! Clearly, changes were occurring. Maximal oxygen uptake also increased by 5%, peak oxygen by pulse by 8% and time to exhaustion by 32%!  Their Wingate test peak and mean power outputs increased by over 8%.

A properly managed sports program can include interval training and will benefit most athletes. No detrimental effects should occur if an athlete knows how to sprint and takes the time to eat and sleep properly following the workout (which they should be doing anyway).

The endocannabinoid system is a group of neuromodulatory ligands and their receptors. They play a role in appetite, pain sensation, mood and memory. Cannabis has clearly been shown to affect these systems. The question becomes what are exercises effects if any? Among other things, animal models of the endocannabinoid system have demonstrated a homeostatic effect on metabolism. Insulin sensitivity, liver function, pancreas function, atherosclerosis, and even intestinal health have been implicated.

Raichlen, et al 2011 decided to test humans, dogs and ferrets on a walking and high intensity running test for plasma levels of anandamide, and 2-arachidonylglcyerol, 2 well known endocannabinoids. 10 fit humans, 8 dogs and 8 ferrets had pre exercise blood drawn for analysis. Heart rate for running averaged at 73% while walking heart rate was 44%.

Humans and dogs showed increases in both markers with a P=0.89 correlation after the run but no change from baseline after the walk. Ferrets showed no change from baseline for either. This tends to indicate that long-distance running at moderate-high intensities cause endocannabinoid responses in mammals which run long distances. Further, this activity helps modulate metabolic activity beyond pure caloric expenditure. This raises the real question of using neurotransmitters to help with therapeutic treatments derived from exercise. Now it is not merely correlation (exercise reduced mil to moderate depression), now mechanisms begin to fall into place and chains of events with the cell and among different systems become more evident. This type of research can really take us into a whole new direction.

Train hard and train safe.

A major hypothesis in rehabilitation has been earlier intervention will decrease long-term disability. Matuseviciene, et al 2013 set out to determine if an extra visit with an expert and written documentation would change long-term disability.

The authors selected the Rivermead Post-Concussion Symptoms Questionnaire to determine levels of disability in the subjects. Participants with a Glasgow coma scale 14-15 were randomly placed in 2 groups (n = 97), standard treatment or standard treatment plus extra information and a visit with a concussion rehabilitation expert. Questionnaires were completed 10 days post injury and 3 months post-injury. 83% of subjects completed the study.

It was found that depression, headache, disability and other symptoms second to the injury were lower in both groups 3 months post-incident. Neither group had a statically different result. This would indicate that information alone will not change outcomes. Consider a sport like soccer where most concussions are mild, most athletes will be fine. Cumulative damage must be monitored but individual incidents seem to show good recovery.

Looking at populations such as Inuit who only had access to a sedentary lifestyle post-WWII and looking at Amish populations, he points out that increasing non-exercise activity has huge implications as literally everyone can take the stairs, park farther from work and the mall, etc.

He concludes with a simple recommendation, on top of your physical activity regimen (whatever it may or may not be), add in 150 min/week of non-exercise activity. The easiest way to do this would be to add a few small walks into your daily routine but he points out that simply walking 10 min from your car, up the stairs, to your desk twice a day is already 20min/day or 100min/week. Finding 10 extra min to move during the day should not be too difficult.

This is old advice but it merits repeating in our society as we continue to become more sedentary- get up and move. No one is responsible for your body except you, so just do it.

Thirty six Futsal players (mean age 17.3 ± 0.7) were randomly assigned into an experimental (EX) (n=18) and control group (n = 18). The EX group performed the 11+ twice per week for 12 weeks.

Results showed that the EX group significantly improved a number of strength measures including (p < 0.05) concentric quadriceps strength (14 – 27%), concentric hamstring strength (9 – 13%), and eccentric peak torque (12.7%). In terms of acceleration & agility, 5m & 30m sprint times were significantly improved by 8.9% and 3.3% respectively (p < 0.05). Finally, two explosive power measures also showed performance improvements as squat jump and countermovement jump improved by  13.8% and 9.9% respectively (p < 0.05).

The results are interesting to note, and the experiment was perhaps performed on a group without prior training. Nevertheless, the results do indicate that a short, time efficient warm-up comprising of a mix of strength, acceleration & explosive movements does have beneficial conditioning & injury prevention effects. The 11+ is a must for any serious athlete!

The authors reviewed different studies. The literature currently demonstrates that while a single bout of lower extremity strength training can decrease running economy severely (20-30%), repeated bout effects and adaptation mediate this decrease. Adapted strength training athletes lose 0-5% of their running economy, depending on the type of training they are performing.

Similarly, downhill running for overspeed work has been incorporated in many running programs but is also known to create soreness from the eccentric activation.  Studies again showed that running for 30 min at a -15% grade generated a 20-30% drop in running economy in athletes unaccustomed to downhill running. Once adaptation had taken place, the drop in performance was 0-7%.

Given that high intensity weight training can produce >90% VO2max while downhill running was measured to average at 65% of VO2max, it has been hypothesized that the 2 mechanisms involved are separate and require different adaptations.

This study provides a basis for what athletes and coaches have known for ages. When integrating a new component into your training, everything suffers for a bit. As you get better and more accustomed to the new stimulus, your whole game comes back and has the potential to improve.