The information provided is for educational purposes only and is not intended to serve as medical or physical therapy advice to any individual.  Any exercise has potential to cause injury or pain if it is incorrectly done or is not the right exercise for an individual’s medical or physical problems. You should consult with a physical therapist or medical provider for individualized advice.

I would imagine that if Usain Bolt ran the 100 or the 200 with his hands in his pockets, he most likely would not have set a world record in each. As stated, before and then again, a successful runner is all about the incremental.  In this case, for this discussion, the incremental is contained in the following areas, namely:

1. stride length: : : a function of scar tissue removal in the hip flexor and hip extensor area (aka flexibility; aka range of motion), properly recruited muscle, and proper system mechanics.
   
   
2. turnover rate : : : at minimum, a function of recruited muscle, and proper system mechanics.
   
   
3. endurance : : : a consistent or desired turnover rate over a specific distance, which is in turn a function of heart rate recruitment, muscle recruitment, range of motion of the associated muscle/joint groups, proper system mechanics, system biochemistry, core temperature, and previous system recovery. 
   
   
4. injury avoidance : : : when flexible, the entire system shares the load vs selected muscle groups.

Let's say at present you run the 100 meters in 60 strides (100 meters divided by 60 strides  = 1.67 meters per stride).  Ok, how fast will I be if I improve each stride by 0.0762 meters (or 3 inches)?  Simple math:  step one:  60 strides in the 100.  Stride improvement is 0.0762 meters per stride, or 3 inches.  60 strides times 0.0762 meters equals 4.572 meters improvement.

So, if you do a race pace 100 meters and you only focus on your number of strides you have now run 104.57 meters in the same amount of time. Well, what will my time improvement be?  Simple math:  (100m minus 104.57m) or 4.57m.  Take this 4.57m and then divided by 100m or (4.57m/100m =0.0457 times 100 (and then multiply by 100 and you obtain 4.57%. Ok, now what? Let's say you run the 100m in say 14 seconds. Simply put, you run 4.57% faster.  The math is again simple:  14 seconds times (1 minus 0.047) equals 13.342 seconds. This is your new 100m time as you are running with less strides and covering the same distance for the same energy expended.

Note:  Bolt does the 100 in nominally 43 strides 

Tip:  Video yourself for your entire event(s) and count the strides.

Now, the same untrained 100m runner is now going to run the 10k.  You take this same logic as above and apply it to the 10k (6.25 miles).  The runner’s stride length for the 10k is 1.25-meter vs 1.667 in the 100m (1.25 meters is about 4 feet 1”).  For a 10k that amounts to 10,000 meters divided by 1.25 meters per stride or 8,000 strides.  A 0.0762-meter  improvement means (for the same energy expended) 8,000 strides times 0.0762 equals 610 meters not needed to be run.  610 meters divided by 10,000 meters and then multiplied by 100 equals 6.1% improved time aka faster - - - all else held equal.

But, before you attack any or all the above, get a base line.  This means, take your cell phone,  put white tape every six inches on the track over a span of 10 meters or 30 feet and then video yourself running either at sprint pace or race pace or both.  Now you have a base line.  Then video yourself running towards the cell phone and then away from the cell phone.

Tip:  You cannot stop what you cannot see (ice hockey goalie saying)/You cannot fix what you cannot see (engineer saying)/You cannot hit what you cannot see (baseball saying).  Thus, seeing is believing. 

These are the basics elements of running mechanics, or you might say where the spikes are digging in first:

1. Bounce or Vertical Oscillation
2. Forward Lean/Foot Plant
3. Arm Drive/Upper Body Twist
4. Cross over
5. Knee Lift/Stride Angle/Stride Length
6. Bounce or Vertical Oscillation:

Bounce of Vertical Oscillation:

Bouncing while running, is also known as vertical oscillation (VO), refers to your body’s up and down movement while running. The larger your VO, the more energy is taken away from propelling you forward. Just how much power is lost or for that matter time?

There has been over the years much “hooey” concerning vertical oscillation.  So, lets simplify it using known engineering/physics principles.  Oscillation is going up while you are striding going out, you are sort of like a “shot” cannon ball, aka, aimed with an arc. You need to be more like a “shot” arrow, aka, aimed with not much of an arc. 

Example:  Bob and Billy are identical twins. Bob and Billy have identical mechanics.  Bob and Billy have the same mile time to the thousandth of a second.  Bob is always more tired than Billy.  Bob has a 3” VO and Billy does not. Bob, when measured, has higher hip flexor strength and hip extensor strength that is greater than Billy. 

Observation:  Bob is the ball and Billy is the arrow. 

This begs the question, why?  Bob is running with an arc whilst Billy is not.  Thus, Bob is running farther than Billy but landing in the same stride length location even though their takeoff points are identical. This is explained with the difference in hip flexor and hip extensor strength.

Goal: Get Bob faster than Billy.

Remember, the shortest distance between two points is a straight line - - spoiler alert - - - an arc aka parabola is not a straight line. Ok, fine, show me the simple science.  If their stride lengths are both 60 inches and Bob has a 3” VO, then at the mid-point of the stride length or 30” Bob is 3” above the centerline.  Using the Pythagorean Theorem, the height is “a” or 3” and the base is 30” “b” - - - so the distance travelled “c” to reach the 3” high point is:  c = a^2 + b^2.  Doing the math “mumbo-jumbo” you get “c” to be 30.1496 inches.  Now multiply that by two as a parabola is symmetrical and the total length Bob actually travels is 60.299 inches. 

Now that difference of 0.299 inches don’t sound like much, but over a mile here is where the law of large numbers rears its ugly head.  Bob and Billy both stride 1,056 times (5,280 feet/5 feet = 1,056).  Now take that 1,056 and multiply that by 0.299” and you get nominally 316 inches or about 26 feet or about 8.8 yards.  That is why Bob is tired as he ran farther, but he matched Billy’s time as he is stronger than Billy.  Now if we keep Bob from bouncing, for the same energy expended he will now be faster than Billy by 8.8 yards or about 1.1 seconds or if he chooses brotherly harmony he will stick with Billy and not get tired.

The implication on distance running is linear.  Meaning, let’s say Bob wants to outshine Billy in the two-mile, the 5K, the 10K, the half, and the full Marathon.  All things being equal, Bob will be approximately 2.2 seconds faster in the mile, 3.4 seconds faster in the 5k, about 6.9 seconds faster in the 10k, 14.4 seconds faster in the half marathon, and finally 28.8 seconds faster in the marathon.  Bob will now be momma’s favorite.

Now some folks contend that vertical oscillation (VO) is like bouncing up a flight of stairs in terms of energy expenditure.  Spoiler alert, it’s not, as running has both a vertical and horizontal kinetic energy component (without getting lost in the engineering weeds). 

Sprinters typically have little to no VO.  VO starts to manifest in 400m and up to, but not in, the 400H. From Takahashi et al., to clarify the factors causing oscillopsia (which is the correct technical term for VO), he investigated head movement, gaze stability, and perception under various situations. The present study suggests that oscillopsia represents a perceptual inability to detect spatial orientation during head or body movements (Takahashi, 1991).

From Tilikete et al, Oscillopsia may result either from impaired ocular stability or impaired compensation or suppression of afferent visual information resulting from normal eye movements (Tilikete, 2011).

Simply put:  VO is caused by a lack of a horizon and to some extent impacted by the inner ear – visual system, termed the vestibulo-ocular reflex.

From Bos et al. A non-linear brain mechanism integrating visual and vestibular information may explain why the least sickness was observed when subjects were blindfolded.  This implies the possibility that if one runs blindfolded the bounce potentially goes away (Bos, 2005).

From Dunlop et al.  A blindfolded fowl rarely walks spontaneously but may be made to walk in a normal manner by being guided by the experimenter's hand. But even in this case there are no conspicuous head movements, thus demonstrating rather convincingly that compensatory head adjustments, at least those varieties considered above, are prompted almost exclusively by visual stimulation (Dunlap, 1930).

Rogge, by default, explains why there is no bounce with 400H runners with the theory that blindfolded balance exercises are important (Rogge, 2021).

Some additional resources for VO:

TIP:  This is assuming that you don’t have access to a flat screen and a connection to a digital camera and you can then just measure it by hand.

How do you measure vertical oscillation?

There was a time when we could only measure vertical oscillation in the lab or give a rough estimate using the visual eye test. Thankfully, technology has evolved, allowing many mobile devices to provide us with a run VO value.  For example, but not endorsed, many Garmin Running Wearables measure run cadence, stride length, ground contact time, and vertical oscillation. These running wearable devices and a heart rate monitor measure “VO” by tracking the number of centimeters your torso moves from a fixed point during each stride. Garmin then provides you with a vertical oscillation ratio which is vertical oscillation divided by stride length. Stride length is your movement horizontally, while VO is your movement vertically.

Many running coaches believe that lower vertical oscillation is more economical, because less energy is wasted going up and down. Garmin has researched many runners of all different levels. In general, more experienced runners tend to have lower vertical oscillation. However, faster paces often come at a cost of somewhat higher vertical oscillation. Vertical ratio (see below) takes this into account. Another advantage of lower vertical oscillation is that it typically means less stress on the lower body at impact.

Reference: https://www.garmin.com/en-US/garmin-technology/running-science/running-dynamics/vertical-oscillation/

Just an interesting FYI on calculating vertical forces is found here.  This is important as it indicates the forces associated with high jump, long jump, triple jump, and to some extent pole vault.

Reference: https://www.youtube.com/watch?v=dysMoBgQKF4

Further equations are provided by Sayers in the Cross-validation of three jump power equations (Sayers, 1999).       

A few good overall summaries are found here:

1. https://sunriserunco.com/do-you-bounce-when-you-run/
   
   
2. Is There an Economical Running Technique? A Review of Modifiable Biomechanical Factors Affecting Running Economy (Moore, 2016)
   
   
3. Running Technique is an Important Component of Running Economy and Performance (Folland, 2017)

FORWARD LEAN/FOOT PLANT:

How often do you see a runner running with their head back?  How often do you see a runner, running straight up and down?  Then you observe, a few RUNNERS that are leaning backwards.  Then you see some of the best runners in the world without a forward lean.  What gives is a rational question, let’s explore this. 

Since this engineer loves simplicity, the proper forward lean angle forces you to run on the front third of your foot.  NOT your toes and not your heels and not flat footed!  This front third is the proper place to plant your foot regardless of you running the 100 or the marathon.  Just an FYI (not to promote) that is most likely why the Newton running shoe is designed the way it is, and why zero drop or low drop at the heel shoes are increasing in popularity. 

Reference:  https://www.youtube.com/watch?v=dABRVg5DgOg

Ok, what if I don’t run on the front third of my foot?  Well, two very not nice things have the potential of happening.  First you run heel to toe.  At minimum that induces shin splints as you are shocking the leg from the ankle to the knee.  Second, gone on long enough, it induces stress fractures. Why? The repetitive shocks eventually compromise bone integrity and the goodness of adhesion of the tendons to the bone. Heel to toe running can also occur during over striding.

TIP:  running heel to toe is like putting the brakes on with every stride and as such your running efficiency is compromised. Meaning, you don’t go quite as far as you would like, aka, your endurance is negatively impacted. Also reference the following:

https://www.youtube.com/watch?v=wlgt_SPE_d4

Flat-footed running shocks your whole body which is not good and does not allow for efficient push off, thus speed is compromised. From observation, flat-footed runners typically come from ice hockey. Why? Well, in ice hockey their ankle/foot is encased in a rigid boot, and they stride by placing the foot flat onto the ice. So, to teach an ice hockey player to run you must induce ankle and foot recruitment and coordination. 

Running on your toes is equally not smart. Much like as outlined above with heel to toe running, running on your toes induce a plethora of foot and ankle issues over time.  Ok, what is a good forward lean angle?  The range is nominally 4 degrees to 8 degrees.

TIP:  the knee to ankle angle is also critical and it also is nominal 4 degrees to 8 degrees.  Meaning, the torso forward lean angle (the angle from the shoulders to the hips) should match the knee to ankle angle more or less.  “Do the video”.

So, what does that look like?  I say it looks like you are running like a chicken.  Now comes the question, what is right for me? 

Simple test.  Take a small digital level and tape it to your spine with the level oriented in the direction of your spine.  Have a friend help.  Now put your ankles together and stand straight up.  Then start to lean forward from your ankles.  You will fall forward and catch yourself with your dominant foot aka leg. Just as you are falling and about to have the forward foot plant have your friend call out the angle in degrees.  Note it.  That is YOUR natural angle, aka, forward lean, not anyone else.

Reference:  https://www.youtube.com/watch?v=zbL4y6fQiiY

Reference:  https://geeksonfeet.com/run/forward-lean/

Ok, how do I correct this if not with shoes?  As you are running, slightly roll your shoulders forward.  This will change your center of mass enough to force you onto the front third of your foot.  This is where video’s NO POSSESSIVE HERE come into play big time.  You are not going to correct this overnight but, in a month, or so you should be fine.

TIP:  Mechanics require feedback, and a video is the best at doing just that.

TIP:  Use a goniometer (angle ruler) to measure your angles on the flat screen.

Reference: https://www.youtube.com/watch?v=o_69XzzrVoU

Reference: https://www.ncbi.nlm.nih.gov.

ARM DRIVE/UPPER BODY TWIST:

As stated earlier about Bolt. You cannot run fast with your hands in your pockets. Take a look at the following video analysis of Prefontaine. Simply put, arm drive, in part dictates stride length and overall mechanical stability. Look at the other runners and their forward lean, stride angle, and arm drive.

Reference:  https://www.youtube.com/watch?v=EZh5D_8H7rg

TIP:  Prefontaine’s arm drive is compensating for his short legs.

So, how are we supposed to use our arms so-as-to maximize performance?

1. Arms at 90 degrees (hands NOT at your pecks or upper chest - - - don’t look like T. Rex running in Jurassic Park)
   
   
2. Hands loose and gently swing with your arms (don’t make a fist)
   
   
3. Always point your arms in the direction you want to go.
   
   
4. When you cross your arms in front of you - - - you shorten your stride length.  (the best example is that of an ice hockey player trying to run)(I still am a hockey player, and it took me three months not to do this way back when).
   
   Reference:  https://www.youtube.com/shorts/ba1d7a9jkqQ
   
   Reference:  https://www.youtube.com/shorts/Lu6RLswUJwE
   
   
5. Some runners twist their shoulders instead of swinging their arms (their arms are at 90 degrees typically but don’t swing in the direction of travel). This too shortens your stride length.
   
   
6.  Drive your arms back to at or near 90 degrees with every stride (don’t have still arms or any other arm angle less than 90 degrees). Now, some of you might think if I am running a 10k why should I drive my arms like a 100? Simple, you maximize your stride length.  Then you say OMG my shoulders get tired - - - well work out with shoulder focus always keeping in mind the 90-degree range of motion required of the arm/shoulder system - - so stretch. 
   
   TIP:  In lieu of a perfect 90-degree angle, use the thumb rule which is make sure your thumb stops mid-point on your rib cage on your back swing and when swinging forward the elbow stops mid-point on your rib cage. 
   
   Tip:  If you really want to maximize your arm drive and you are just plain weak (which is quite true for most) stand in front of a mirror and do arm swings five minutes on five minutes off for a total of 15 minutes of arm drives three times a week for a month using two-to-five-pound weights in each hand. After a month you should be fine.
   
   Reference: https://mensrunninguk.co.uk.
   
   
7. Video yourself front back and from the side at least once a week.

CROSS-OVER:

Cross-Over is the situation where you place one foot in front of the other when you run.  It’s as if you are running like a person modelling clothes on the “fashion runway”.  This deliberate cross-over technique is referred to as the “catwalk”.  Take a look at the following.

Reference:  https://www.youtube.com/watch?v=IEYQ4TvlQZ4

Simply put, this leg motion shortens your stride length and it’s not uncommon in runners.  This is solved by training the brain.  How is quite simple.  Start with a brisk jog on the track with either the right or left foot landing on the lane marker and the other not landing on the lane marker.  Alternatively, have your feet on both sides of the lane marker.  Do this 20 minutes a day, three days a week for a month.  In theory after a month, you have retained your brain. 

TIP:  Video yourself before, during and after for the visual feedback.

KNEE LIFT/STRIDE ANGLE/STRIDE LENGTH:

No pun intended but this is where the spikes meet the “mondo” or the rubber meets the road. There has been so much written about this topic, in Latin, one would say we are at the point of “ad nauseum”. So, as an engineer I am going to attempt to apply Occam’s Razor (OZ) to the subject at hand. For clarification, the Razor has nothing to do with shaving. OZ, which is a problem resolving method, is best paraphrased this way, the simplest explanation is typically or usually the best one. In the modern engineering world this is sometimes referred to as Root Cause Failure Analysis or Analytical Problem Solving. Remember, simple is in the eye of the beholder and based on sound science and effective observations and logic.

TIP:  Don’t oversimplify.

Ok, let’s get started.  Knee lift is just that, how high you can lift your knee with or without support.  Knee lift is a function of scar tissue or adhesions of the fascia in your Hip Flexor and Hip Extensor area and how much Hip Flexor and Hip Extensor muscle you have recruited. Without significant knee lift you cannot run fast.  Just look at Bolt.

TIP:  Scar tissue adhesions limits your range of motion as it acts as a blocking mechanism.

Consider Alberto Juantorena in the following:  https://archives1.sundayobserver.lk/2022/03/06/sports/cuba%E2%80%99s-alberto-juantorena-only-athlete-bag-400m-800m-double-olympics

Start with taking a digital picture of the athlete at either sprint pace or race pace.  Then project the picture onto a flat screen.  (Then, to measure the knee lift, it is combined with the measure of stride angle).  Using the same example of the above, using a Goniometer, on the flat screen, do the following.  Put the center of the meter on the center of the hip.  Then draw a straight line from the hip to the knee and from the hip to the foot.  Adjust the meter so that centerline of each arm follows each line.  There you have it.  Stride angle, which has as its major component, knee lift.   

Reference the following excellent overview of the method. 

Reference:  https://www.youtube.com/watch?v=pVZID4kWDCk

TIP:  The greater the stride angle the greater the speed all else held constant.

TIP:  As you train your stride angle should increase.  This angle is an objective      feedback loop relating to training.  So, chart your progress.

Comment:  Ok, I cannot run a 5k like a 400.  Yeah, I get it.  But, if at a sprint you are say at 120-degree stride angle - - - - - you at normal 5k race pace will be at nominally a 90-degree stride angle. The flip side to this is if you are at a 90-degree stride angle at a sprint you most likely will be at a 70-degree stride angle for your race pace 5k. Its Bob and Billy all over again, but this time it’s not muscle recruitment and VO but stride angle. 

Ok, I get it, now how do I get rid of the scar tissue and recruit muscle?  Really simple.  Other than some very specific deep tissue massage techniques, the next easiest method is the Hurdle Drill developed by Dr. Tatiana Zelentsova which resulted in two world records (drug free) for her and eventually many championships of her athletes she coached. 

Reference:  https://www.youtube.com/watch?v=Rgcej5VkBsk

Reference:  https://www.youtube.com/watch?v=kFjhNGigBi8

Per Dr. Zelentsova (personal conversation), when you hyper extend a muscle group, such as walking over a hurdle you break up scar tissue or injured fascia. When you work out you generate micro-adhesions.  This means that one should do the hurdle drills every day so as to prevent accumulated range of motion injuries and range of motion issues (aka less knee lift and stride angle) that negatively impact performance. She also went on to point out that when you hyperextend a muscle group under light load you recruit more muscle without creating bulky muscle groups and the associated scar tissue (aka, adhesions).

How often do you “do” the hurdle drills?  A reasonable routine is M, W, F with weights and T, T, S without weights, aka the cardio day, with Sunday being a rest day. 

TIP:  It’s all about recovery not the workout.

TIP:  For specialty athletes like pole vaulters, M, W, F with weights, and T, TH for specialty mechanics.  Saturday would be cardio, and rest on Sunday.

What about weights?  Well, first off don’t run in ankle weights.  That is a no-no.  Second, let’s assume you only have access to the school’s hurdles.  Then let’s assume that the lowest point of the school hurdle is 30”, and your inseam is around 30”.  This means you realistically can only use the 30” and 33” setting.  For folks with greater inseams could go up as high as 36”. 

Begin the process with no weights.  Set 10 hurdles at 30 inches.  In month one “do” 500 hurdles MWF.  Some folks would start at 30”.  Then in month two go to the next button up on the hurdles or 33”.  Now, if you can, in month three go to the next button  setting 36”.  If not, stay at the month two setting.  Ok, now you have broken up your scar tissue and you should realize a stride length improvement of between 3 inches and a foot.

Observation:  After three months you should see a speed improvement of between 3% and 5%.  

On month four you go to 2 lbs. on each ankle.  Weights on M, W, F.  Now on the T, Th, S you do the hurdles without weights, and you add cardio (see cardio tile).  If you can only do two hurdle heights, then month three is identical to month two.  If you can do three hurdle heights all the better.  Now comes month four of weights.  Now, at this point, you then go to two more pounds on each ankle (now at 4 lbs. on each ankle) and back down to the starting hurdle height and then repeat as before.  

TIP:  It’s about 8 lbs. per ankle per year.

You are thinking what is the upper limit to the weights? It appears the limit is what you can strap to your ankle and shin and that appears to be about 30 lbs. on each ankle.  If you physically cannot do “that much” increase the number of hurdles you can do with the weight that the maximum for you. 

TIP:  if you “feel the burn” stop and go down one pound as you are tearing tissue which quickly generates adhesions.

This now brings us to stride length.  Again, break out the cell phone and the flat screen, some white tape and a tape measure.  Every month do a race pace and a sprint pace stride length to measure progress.  Simply put, the stronger the hip flexors and hip extensors are the longer the stride length (toe off to touch down) assuming the absence of scar tissue and the presence of good mechanics.  The alternative is to measure a distance such as 20 meters and count how many strides you have over that distance.  The math is simple:  distance in meters divided by number of strides.

Note:  stride angle maximum is nominally 125 degrees.  Bolt was at 114 degrees (sort of). 

TIP:  work at running in such a fashion that your heels brush against your glutes even if you run distance. 

Reference:  https://www.youtube.com/watch?v=ZrCm6UA2U1k

In the end, it’s all about the incremental. Occam’s Razor at its best or as I said for many years in engineering, it’s the 80/20 rule.  Meaning you obtain 80% of the results with 20% of the input.  This is also known as the KISS (not the rock group) Principle. 

Good luck and keep in touch.

References

Barry CM. c2014. "Who sharpened Occam's Razor?". Irish Philosophy. Cited 2022 Aug 5.  Available from https://research.wou.edu/c.php?g=551314&p=3785531

Bos JE, MacKinnon SN, Patterson A. Motion sickness symptoms in a ship motion simulator: effects of inside, outside, and no view. Aviat Space Environ Med. 2005; 76:1111–1118

Dunlap K, Mowrer OH. Head movements and eye functions of birds. J Comparative Psych.  1930;11(1):99–113. https://doi.org/10.1037/h0075905

Folland JP, Allen SJ, Black MI, Handsaker JC, Forrester SE.  Running technique is an important component of running economy and performance. Medicine and Science in Sports and Exercise.  2017;49(7):1412–1423. https://doi.org/10.1249/MSS.0000000000001245

Moore IS.  Is There an economical running technique? A review of modifiable biomechanical factors affecting running economy. Sports Medicine.  2016;46(6):793–807. https://doi.org/10.1007/s40279-016-0474-4

Rogge AK, Hamacher D, Cappagli G, Kuhne L, Hötting K, Zech A, et al. Balance, gait, and navigation performance are related to physical exercise in blind and visually impaired children and adolescents. Exp Brain Res. 2021;239:1111–1123. https://doi.org/10.1007/s00221-021-06038-3

Sayers SP, Harackiewicz DV, Harman EA, Frykman PN, Rosenstein MT. Cross-validation of three jump power equations. Medicine and Science in Sports and Exercise. 1999;31(4):572–577. https://doi.org/10.1097/00005768-199904000-00013

Takahashi M, Okada Y, Saito A, Takei Y, Tomizawa I, Uyama K, et al. ‘Roles of Head, Gaze, and Spatial Orientation in the Production of Oscillopsia’. J Vest Res.  1991 Jan 1;1(3):215 – 222.

Tilikete C, Vighetto A. Oscillopsia: causes and management. Current Opinion in Neurology. 2011 Feb;24(1):38-43.  DOI: 10.1097/WCO.0b013e328341e3b5