Common Sprinting Traits

Sorry about the current delay in the blog.  I decided change course and present a review paper on commonalities in sprinters and sprinting.  This will relate back to some of the acceleration blogs as well, but I will be doing more than concentrating on stride and step characteristics.  The review will include areas such muscle architecture and biochemical composition.  I will be looking for plenty of comments as well.

Acceleration: The Adjustable Leg Spring (Part 3)

The last 2 posts have dealt with energy supply, the curves dealing with velocity, acceleration, and jerk in sprinting, and how if we are to improve acceleration the distance in the race and amount of time are longer than in our previous competitive conditioning state.  This post is going to offer insights in the particulars of what is happening in acceleration and why we must travel further in distance and longer in time spent to improve acceleration.   Those particulars happen to be step rate, step length, contact time, flight times, range of motion during ground contact, and leg stiffness.

When a sprinter starts an acceleration the exhibit their slowest step rates, shortest step lengths, longest ground contact durations, shortest flight times, greatest range of motion during those ground contacts and the least amount of leg stiffness and as the sprinter accelerates to maximum or optimal race velocity the step rate becomes faster, the step length becomes longer, the ground contacts become shorter in duration, the flight times become longer in duration, the range of motion becomes shorter during ground contact, and leg stiffness increases.    The measurable attributes of acceleration show one important feature, the approach to a minimum or maximum value, aka in calculus this is referred to approach the limit of attribute X.  This further underscores why as we approach the limits to maximum or optimal race velocity from an initial velocity we are approaching zero acceleration from its peak acceleration.

How so?  As leg stiffness approaches the limits to the forces involved in acceleration the rate of change in velocity is slowed as step rate reaches it peak and then tails off slightly while step length continues to increase at slower and slower rates until it peaks before deceleration in the maximum velocity phase.   Which leads us to why does step rate peak before step length in and why does step rate slow before maximum velocity declines?   The answer is leg stiffness which depends on shorter ground contact times to increase or maintain stiffness for step lengths to still be increased which requires longer flight times, but flight times are relatively constant per the Weyand study of 2000.  Meaning the take-off angle is lower in faster athletes at the end of ground contact as take-off angle is related to vertical velocity and horizontal velocity and horizontal velocity.  This down regulation of step rate can also be related back to the CP energy supply problem as non support work during a stride requires mechanical work at maximal intensities, but with maximal power output bound to drop by more than 50% after 5 or 6s of work from the CP system, step rate has to be reduced and the system must rely on momentum and any current positive acceleration to extend maximum velocity and utilize the elastic properties of the legs to continue acceleration till maximum velocity or continue to hold maximum velocity.  This is where range of motion during ground contact comes into play, the smaller the range of motion and the shorter the ground contact the stiffer the leg spring.

So how does improving these attributes through training put us further in a race in distance and keep us longer in acceleration.  The answer is simple, if we changed the maximum stiffness one can reach while running and step rate cannot change appreciably with training because it helps control stiffness, because we are approaching a minimum in ground contact time, a higher velocity is reached with an improvement in step length and if we changed the initial impulse to which we use to start a race we are effectively starting out with a smaller leg stiffness value and this should mean that we cover more distance in the same number of steps and that the range of values that leg stiffness goes through is higher meaning that it will take longer in time till ground contact minimizes and stability is reached in the stride pattern which means maximum velocity is reached.

The outcome of longer step lengths and shorter ground contact times reflects directly toward the waveform formula of velocity, step length x step rate = velocity.  step rate is ground contact time + flight time, and step length is related to the parabolic ballistic trajectory of horizontal velocity and vertical velocity.  With flight times being relatively constant once acceleration ends between different velocities, step rate has a ceiling for optimal velocity and endurance of velocity which relates directly back to stiffness affecting the step length by harmonizing vertical velocity and horizontal velocity.  The direct affect on acceleration and its duration and length of distance it covers is dictated by leg stiffness and a stiffer leg means a longer distance and longer duration of acceleration which all reflect back to a higher velocity.

Acceleration: The Asymptotic Curves (Part 2)

I took a lot of heat from a commentator in the last blog about how acceleration gets larger and larger. It’s true to a certain extent that the average acceleration gets larger deeper into the race, but the average acceleration of the first three steps and the instantaneous acceleration of the first step are the largest accelerations a runner will experience in a race. However, lets look at relentless’s point of acceleration get larger with velocity.

I took the liberty of breaking down the splits of several races of different athletes below:

Figure 1:

As you can see average acceleration for 10m splits has peaked by 20m in even the best runners in the world. Also of note is the similar nature of the curves to those of other researchers.

This brings us to the point of time involved in acceleration and its relation to maximum velocity. To reach a high maximum velocity on the order of 11+ m/s a sprinter must have a decently large initial impulse and they must also have a controlled rate of jerk once positive acceleration has peaked. If Jerk is not controlled and acceleration goes from 3 m/s^2 to 0 m/s^2 in a matter of 10m or less than a second of time then a sprinter will have reached his terminal velocity in a race, but if that sprinter slows the decay in acceleration his velocity will go higher and higher albeit at smaller increments, thus extending the distance in race one is accelerating and the amount of time spent in acceleration.

Acceleration - The Sprint Velocity Curve and Energy Supply. (Part 1)

Much has been made lately of acceleration at websites, Elitetrack and Bearpowered , I frequent. So I decided to do a little review for all of us.

Acceleration in Newtonian mechanics is the rate of change in velocity. It’s the means to achieve as high as race velocity that is optimal or wanted in a sprint race. In a sprint race the energy we use to create acceleration comes from the ATP-CP system which combines free ADP with CP to form ATP. In what I consider a landmark study of acceleration dynamics in an article in Medicine and Science in Sports and Exercise in 1979, Volkov and Lapin discuss their findings of analyzing the sprint velocity curve the following.

Our results indicate that the maximal running speed is attained 4-5 sec after the start

This sets the precedent that maximal velocity has a finite time in which to be developed and the reasoning for this is stated as follows.

The energy supply of these first 5-6 sec is mainly carried out through the cleavage of intramuscular reserves of ATP and creatine phosphate (CP). For that reason, the maximal speed in sprint running may be considered as a mechanical equivalent of maximal rate of energy liberation in the alactatic anaerobic process (maximal anaerobic power). The time of maintenance of the maximal running speed will depend in this case on the overall storage of creatine phosphate in the working muscles, i.e. will be determined by the capacity of the alactatic anaerobic process.

While we have come along way since 1979 when this was published, these two researchers seem to be spot on about the limiting factors in acceleration and maximal velocity. Hochachka wrote in a 1985 review of Fuels and Pathways as Designed Systems for Support of Muscular Work for the Journal of Experimental Biology:

On short and long term basis, the amount of PCr available for burst work seems to be controlled by hypertrophy, not by concentration adjustments (Hollozy and Booth, 1976)

This seems to fit the guidelines of sprint athletes requiring more mass than their endurance counterparts set about with Weyand’s Structural Basis for Human Movement. However, Hochachka went to show that their seems to be a ceiling for phosphagen storage in skeletal muscle. This suggests that while hypertrophy is needed for phosphate storage the hypertrophy associated with phosphagen storage is also limited and “work based off the energy demands of the ATP-CP system are only possible for very short times, 5-10s in mammals.”

This brings us to K. Sahlin and others work entitled Energy Supply and Muscle Fatigue in Humans from Acta. Physiology Scandinavia in 1998.

PCr breakdown can contribute to ATP generation for more than 20s because ATP is supplied also from other energy sources and because energy expenditure decreases after a few seconds of contraction. After just 10s of maximal exercise the power output decreases. These first signs of fatigue correlate with substansial decreases in muscle PCr. On the basis of thermodynamic considerations, one would expect that the maximum rate of PCr breakdown (ATP Generation) would decrease when PCr decreases. Availability of PCr may therefore be a limiting factor for power output even before the muscle content of PCr is totally depleted. This may explain why the power output decreases after 5s of maximal cycling despite the fact a considerable portion of PCr remains in the working muscle.

Therefore we don’t even have to use all the creatine phosphate from creatine before maximal power output decreases. So what’s the big deal with the review? Nothing has changed from 1979 right? Wrong!

1. The time spent in acceleration in any 100m race yet has exceeded 7s for the winning runner in any race.
2. The role of mass and particularly that caused by hypertrophy has changed or needs to be reviewed in the context of the structure of the individual as a result of training and not to be training for added mass.
3. We don’t use all the intramuscular phosphates we haved stored in the muscle and muscle power outputs related to energy from ATP drop after 5s regardless.

Now lets get back to acceleration and the mathematics involved. If we do everything right we have just less than 7s to reach the highest velocity we can. If we accelerate for 6 seconds at maximal volition in all likelihood we will attain a higher velocity than accelerating for only 4 or 5 seconds. To accelerate for 6s maximally we need a higher initial impulse than we do for accelerating for 4 or 5 seconds. This is due to the impulse-momentum theory were force times time equals mass times change in velocity.  Hence a greater production of force and with it a greater acceleration requires a greater impulse which leads to a greater velocity.  In a very simplified view, from the start of our acceleration which is the largest change in acceleration we have during a race the amount of positive acceleration drops on each consecutive step till acceleration reaches zero which indicates that maximum velocity has been reached.  This suggests empirically that a sprinter must limit the rate of decline in acceleration to maximize velocity and not just to reach maximum velocity as quick as possible but to do it in the least jerky way (jerk is the rate of change in acceleration) with the largest impulse.   This is how acceleration is extended beyond the 4-5s range to the 6-7s range.   To put it mildly a sprinter with who accelerates only 4s would need 50% more of the initial impulse to the velocity of  a sprinter who accelerates for 6s.  As f x 4 requires a 50% larger f to equal f x 6.  This is the double edged sword of acceleration.

Are Angles Important?

A while ago on the site Elitetrack.com there was a heated discussion about the merits of technique training.   On one side of the debate you had Vern Gambetta whose blog started this debate, Mike Young, David Kerin, Carl Valle, myself and others, on the other side of the debate was Ken Jakalski and Barry Ross of BearPowered.com.  While there is agreement between both sides on the importance of forces during ground contact there is little agreement about angle of attack and if this can or cannot be changed through technique training.   The side of the debate I was on was pro-technique and while we all may not agree on what technique training constitutes we agree that direction of force is just as important as magnitude of force in the role of running/sprinting speed and we don’t believe in Mach and Form drills as technique training.   The bearpowered side took on a very simplified view of Dr. Peter Weyand’s work on the role of vertical support force in the role of sprinting speed and that technique cannot be taught.  Although I believe when we wrote about technique the bearpowered advocates would counter with how do you get precise angles, etc..?   while pointing out studies of the Mach A and B drills.  Inevitably, it became a strawman against strawman argument as meaning of the word “technique” means different things, but one thing I did write about in one post on the thread was the importance of angle of attack and joint stiffness.  Again I was refuted, because how do you train precise angles?  Technique training equals specific training in my book, the more specific the training is to the event/task/skill then more technical that training is and to the bearpowered group technique means slow movements and drills.

So when I was reviewing older research articles relating to the spring mass model of running.  I ran by a statement in one of the articles by Dr. Claire Fairley who worked at the same lab with Dr. Weyand for a period and both of whom are influenced by some of the greatest biomechanists of our time Drs Chester Taylor, Thomas McMahon, and Norm Heglund.  In the Farley’s article on “Mechanism of Leg Stiffness Adjustment” Dr. Farley references the Davita and Skelly article on “Landing Stiffness on Joint Kinetics and Energetics” which was the foundational paper in my Advanced Biomechanics graduate school course at Illinois State University under Dr. Steve McCaw who presented a presentation with Dr. Devita at the International Society on Biomechanics in 2005 on joint torsional stiffness. The reference was to leg geometry and specifically I quote as follows from the Farley article on page 1045 who was interpreting Devita and Skelly from 1992.

When humans land from a jump, the stiffness of the landing appears to depend on knee angle at landing.

13 years passed since the Devita and Skelly article to 2005 when this time McCaw & Devita make the same statement as Devita did with Skelly in 1992.

While increased joint stiffness is evident
at the hip, knee and ankle, the disproportionate increase in
knee joint stiffness suggests modulation of knee joint stiffness
is the primary mechanism of adapting to a landing on one leg.

Furthermore, the McCaw and Devita presentation referenced back to another Farley article.

suggesting neuromuscular control strategy adjustments
according to the number of limbs available to absorb energy.
Quantifying leg stiffness and individual joint stiffness allows
evaluation of neuromuscular control strategies [2]. When
hopping in place, leg stiffness adjustments to alter hopping
frequency or height occur primarily by adjusting ankle joint
stiffness [2]

then they go further to again reference the Devita & Skelly article

Landing differs from hopping since landing does
not require a subsequent flight period. Landing research
identifies the knee as the primary contributor to energy
absorption, but the ankle contribution increases if a “stiffer”
landing technique is used [3,4].

This made me think and to think critically like Dr. McCaw stressed to do in his classes. My first thought was were was this article hiding or buried during the argument on the thread on the Elitetrack website? Granted I have to make some assumptions to link hopping, landing, and running together, but Drs. Farley, Weyand, McMahon, Heglund, and Taylor had already linked hopping and running together. So now with Devita & Skelly linked to Farley and McCaw & Devita relating back to each other I have the link between landing and hopping.

How so? When we prepare to land we alter our limbs to absorb the impact. In doing so we alter the stiffness of the leg as a whole from the foot to the torso and at each joint. If we are going to just land as a gymnast does the tendons/ligaments/bones/muscles dissipate the force and don’t return it like they do when running, sprinting, or jumping. Running has forward momentum this forward momentum is maintained by reducing braking forces on ground contact. A stiffer leg on ground contact has a shorter contact time with the ground. It will also produces higher vertical force readings on a force platform. So if the angles of the limbs are important to with respect to stiffness, they are also important to the creation of higher vertical forces, velocity, and maintenance of that velocity.

Therefore a whole range of questions now arise, how do affect the attack angle of the leg? I believe this is answered by increasing muscular strength eccentrically, isometrically, as well as concentrically from the core muscles on down the kinetic chain. It also has a lot to do with dynamic flexibility and mobility about the hip, knee, and ankle joints along with the specific and general strength of the muscles surrounding those joints. However, one key feature was left out of this debate and that was the issue of accelerating to maximum or optimal race velocities. This to affects our ability to run fast, because you can only sprint or run as fast as your acceleration capabilities can propel you.

Quantity and Quality

Everyday in coaching circles I hear or read how this coach has a more quantity based training program and that coach has a quality based program. Sometimes I hear how quantity is bad and quality is good or how quantity prevents injury and quality causes injury. All of this is nonsense as quantity and quality are not opposites but linked. There is no such thing as quantity over quality or quality over quantity. For a proper adaptation to occur in training one needs both quantity and quality.

In training athletes, quantity of work is quantitative (something we can measure objectively or empirically) and quality of work is both semi-quantitative and semi-qualitative (subjective rating based on observable traits). There is no single way to objectively measure the quality of a workout, but there are traits we can effectively measure and relate to quality such as pace, distance, reps, but what each of those is different for every individual athlete.

In practice quality is easy to identify as the quality of work should regulate the quantity of work being performed. When you see pace dropping rapidly, an athlete struggling to lift a weight or throw, or athletes are showing a lack of skill at tasks they have completed skillfully before then the workout is lacking quality. Don’t allow this to happen, stop the workout and re-evaluate the training plan for the next couple of days or even 2-3 weeks and back off on quantity of work and focus on looking for improvements in quality of completing work.

Quality as a function of exercise prescription in program design is related event specificity. The more mechanically and physiologically an exercise is related to the event or task used in competition the higher quality of work it is. In sprinting this means sprinting is higher quality work than bounding which is higher quality work than skipping which is higher quality than hopping. However does a 3 mile run have more quality than a set of hopping exercises for a sprinter? That depends on intensity and duration of the hopping. Should 400m specialists do 30-40m acceleration drills constantly? Should 800m runners be running 20 miles at least one day a week? Should a 10k/marathoner be running 100m sprints on a regular basis?

Building a better athlete is about having the athlete be able to do both higher quality work and more of it. It takes time and patience, speed, strength, power, endurance, stamina, balance, coordination, etc… they all take time to develop.

Core Misconception

Almost every time an athlete moves their “core” muscles are being worked and stressed. If the athlete is doing an event specific task or skill then they are working their “core” muscles with related event specific demands. So why is it coaches and athletes set aside time to specifically train the “core” muscles on non event related tasks? The “core” is the foundation on which we move and thus is highly important to athletic success. This presents a major problem in most training programs for several reasons, the “core” tends to be overworked and fatigued more so than the rest of body, loss of valuable practice time that can be done working on event specific training, and most “core” work is done either isometrically in a static hold and/or concentrically in a dynamic, but slow and controlled manner. However, “core” strength and power in sporting activities also comes from fast, dynamic, and very forceful movement utilizing all 3 types of muscular contractions are used, eccentric, concentric, and isometric.

For the sake of brevity, I will only focus on a couple of movement patterns, jumping, running, and throwing to illustrate my point. When an athlete jumps, either from a static position or a dynamic movement such as a run up, the “core” muscles perform a stretch-shortening cycle (SSC) to take-off. The stretch-shortening cycle involves both eccentric and concentric contractions to produce the necessary force required to take-off. When the athlete lands, the athlete utilizes eccentric contraction to absorb impact forces as well as initiate a SSC to produce a concentric contraction and they also utilize isometric contractions to stabilize the posture. When athlete runs, the “core” muscles prepare for landing and take off in the same manner as jumping and when an athlete throws with all the twisting of the torso and the hips in opposite directions and back towards each other which creates the corkscrew effect we again have eccentric and concentric contractions to make this happen. So why in the world are we setting aside 15-30 minutes 3-5 days a week doing static stabilization holds, crunches, swiss ball activities, russian twists, etc… ? To be honest I don’t have a clue, except Coach A does it so Coach B does it and so on and so forth. I didn’t come to this conclusion as if I never set aside training time for “core” training. I came to this conclusion because I did set aside time to do “core” training and then about 2-2.5 years ago I started questioning the benefits and it wasn’t till last summer I decided I was through specifically working the “core” muscles.

About 3 years ago at this time of the year I had an epiphany. I asked myself how do I make my sprinters and jumpers run faster and jump farther? I always question my training plans and philosophies at this time of year and relate them to my goals, so this was nothing new. However, I came to the realization that I need more specific training of higher quality. I couldn’t lengthen the season allotted training date range and I couldn’t alter the training time in a day so things had to be removed from my training sessions. Low and behold about 6 months later “core” training segments within training sessions were going to be eliminated at all cost. “Core” Exercises were going to remain in the form of general strength activities and circuit training either as replacement for tempo endurance, part of general conditioning, or as part of warm up and cool down routines. Emphasis was no longer placed on body parts, but on movements and energy system training. As a coach such an epiphany instantly made me a better coach as I became more aware of the capabilities of my athletes and how to fix deficiencies while still building a better all-around athlete with respect to event demands. I was no longer causing a new deficiency or two while trying to correct an old one.

In this time I also came to the conclusion that the “core” doesn’t just consist of the muscles in the mid torso, but it also consists of the hip flexors, extensors, adductors, and abductors as well. This is another key area of “core” muscular development many coaches and athletes miss out on. 20 years ago, if an athlete did situps they were working their “core” nowadays, most would argue you are not working your core, because the situp requires greater use of the muscles which cross the hip. Situps are probably the best non specific “core” exercise an athlete can do, because it’s a cyclical ballistic movement pattern which requires a large range of motion and has a SSC (Eccentric followed Concentric contraction). So I decided what should sprinters and jumpers do to work on core strength through situps and I decided sprinters and jumpers needed to perform situps and work on doing as many situps as possible in a specified time frame which ranged from 10-40s in duration. What do I get out of doing situps this way, is better hip mobility and dynamic flexibility about the hip, energy systems training, and eccentric work done on the “core” muscles. Do I make athletes do situps every day? Not even close, but on a day when weather dictates we cannot run outside I know I can still stress the “core” muscles with eccentric contractions it’s likely to face in an event specific setting. Nowadays, my “core” training consists of a balance of eccentric, concentric, and isometric contractions in non event specific work, to push the “core” muscles beyond the constrained stress allowed by event specific work.

The Circuit - Something besides general strength work.

I developed a circuit a couple of years ago that was successful in keeping my sprint athletes conditioned during the winter time when they could not run outside do to weather and I did not want them pounding around indoors in the hallways.  “The Circuit” as it is called mixes a few different training modalities into one big circuit.   It’s part general strength, plyometrics, core, and explosive power.  Some would say this is a no-no to mix such training modalities, but isn’t sprinting and jumping a mixture of general strength, plyometrics, core strength, and explosive power.   Exercises can be substituted in and out the routine to add variety.   I would suggest even occaisonally substituting in an exercise which is a ballistic general strength exercise like a jumping jack or burpee or something similar as a core, plyo, or general strength exercise since they do overlap onto all 3 of those.   I like substituting both ankle hop exercises for drop landings and tuck jumps.   It all depends on the mobility and stress you want to get from the circuit.  I would take a 5-10 minute break between sets and do 2 or 3 sets.  Try it out and comment please.

THE CIRCUIT
1. 10 Pushups
2. 20s Prone Stability
3. 20 Sit-Ups
4. 10 Lateral Ankle Hops
5. 20 Mountain Climbers
6. 20s Left Lateral Stability
7. 15 Leg Lifts
8. 10 Split Squat Jumps
9. 10 Good Mornings w/ medball
10. 20s Right Lateral Stability
11. 15 Russian Twist Sit-ups w/ medball
12. 10 Burpees w/pushup
13. 15 Medball overhead Presses
14. 20s Medball Overhead hold
15. 15 Reverse Crunches w/ Medball
16. 2x Ankle Hop Dot Pattern (Form a square in one direction, then the opposite direction)
17. 10 Lunges
18. 20s Pushup stability
19. 15s Superman stability
20. 5-5-5 Squats

Power Endurance: An Alternative Approach to Standard Periodization? (Part 2)

As stated in part 1 of this theme on power endurance, power endurance is simply work-capacity.

So lets look at how we measure it. We can measure Power with lifting 1RM with as fast as movement possible with something like an olympic lift, the distance of a standing long jump, vertical jump, or medicine ball throw, or the time to complete a short distance in runningsuch as 30m or 40yd dash while an athlete is still accelerating at the time they cross 30m or 40yd mark. All these measurements give a coach a standard from which to work with. So what about the endurance part? Well that’s the kicker, you don’t need to measure the endurance or volume. You train your power-endurance by doing more work in less time, by working at intensities appropriate for your event or events by paying attention to duration of a set of work. To boost your power-endurance you simply do more work in the same time as other sessions by adding sets or repetitions of work or increasing the power involved in those sets.

The goal of power-endurance training should be to increase the power output in a given workout without sacrificing work completed for a set time. It also provide a coach a new means with which to structure periodization in their training programs.  As the competitive season approaches the power output to a repetition of competition specific work should become similar to the power output of expected in competition.  This is hardly a new concept as it has been practiced by the best coaches in track and field for many years.

In track and field, Clyde Hart’s Baylor 400m sprint program progresses from longer distance/duration repetitions to shorter distance/duration repetitions.  Hart’s program is a classic long to short program.   Numerous coaches have used short to long programs or ends to middle where endurance for event specific work is the culmination of all physical activity performed throughout the season.   All 3 types of programs have been used effectively in building great runners.   What none of the successful implementations of these programs seem to have is a maximum strength or bodybuilding phase in them.    Hart’s “strength building” phase is really a muscular endurance phase based on hitting certain times exactly over certain distances making it power-endurance.

The preparatory phase of standard periodization is about building power-endurance for event specific work. There is no need to go from Body Building to Max Strength to Power work, they should be part of training process throughout the preparatory and competitive phases.   It does a coach no good to build an athlete who can squat 400 lbs and clean 200 lbs in the preparatory phase and come the end of the competitive phase the same athlete can barely squat 300 lbs or clean 185 lbs.   Just like it would be counterproductive for the same athlete to run 100m in 11.3s at the end preparatory phase and then at the end of competitive phase for this athlete to run 11.5s for 100m.   A coach can work maximum strength but still focus on power, just as he can work on endurance and focus on power.   Improving power output relative to specific events is how an athlete improves performance.   Stressing the biological systems during training which are stressed in a competitive event allows the body to adapt those systems to demands of the event based on the abilities of the athlete.

None of this is new, in fact it’s all old, it’s just that we have been enamored by the guru’s who are selling fool’s gold based on faulty/deceptive interpretations of scientific literature, inventive exercise routines, and short term adaptations that produce improvements because they have never been used before, but the long term development of the athlete slumps after diminishing returns of the new guru program doesn’t help the athlete attain/maintain event specific proficiency as previous long term adaptations have diminished in favor of the newer short term adaptations.

Power Endurance: A new approach to Work Capacity training? (Part 1)

Work Capacity is often used in coaching circles. However, there seem to be many definitions of what Work Capacity means.

Vern Gambetta wrote on his blog in article title Train for Work Capacity Not Endurance

Work Capacity is the ability to tolerate a high workload and to recover sufficiently for the next workout or competition.

Here’s an example of an interesting definition.

Amy Deem, Head Track and Field coach at the University of Miami, in a presentation for the USTFCCCA described work capacity training for sprinters as.

• Circuit Training
• Extensive Tempo
• Intensive Tempo
• Special Endurance

So what is work capacity? well if a coach is from the old exercise physiology school, it is likely their definitions are closely related to Astrand and Saltin and to the etiology of the words involved. Work is just force x distance and capacity is volume, therefore it is the limit to the amount of work one can perform. Generally this is known as endurance. Work capacity is mathematically expressed as:

W_max = F_avg x d_max

Force (F) is technically strength and Distance (d) roughly translates to endurance therefore work capacity is a measure strength endurance. If we are focused on accomplishing getting an X amount work done without regard for time then Strength Endurance training is the way to go. However, athletes, firefighters, military personnel, freight loaders, field workers, etc… all have certain time requirements involved in their activities. In the case of the athlete, if any two athletes have the same work capacity the produces the higher average power output will win.

Power is Work divided by Time (P=W/t). So lets introduce a new concept it’s called power endurance, the ability to produce a certain amount work over a given period of time. No matter which you cut it, time and distance are both values which measure endurance. Power on the other hand which is both time and distance dependent is a rate which provides a measure of intensity. Intensity together with Volume gives Load and training Load in this instance along with rest gives us adaptations. Remember Coach Gambetta’s quote about high workload.

Given the definition provided earlier Power Endurance is simply Power x Time which reduces back to Work completed. This is where many coaches get lead astray, they focus on work completed without regard for time when stressing work capacity. How many distance coaches do you know whose focus is solely on mileage? How many football or throws coaches are stressing 1RM squat, deadlift, or bench numbers? How many jumps coaches stress # of ground contacts each day? How many sprint coaches are stressing # of reps or intervals each day? If you are a coach think about the feedback and cues you are giving your athletes do they involve only a distance, only a certain number of reps, or only a certain time from start to finish? Athletes take heed of the same things. If you are only focus on distance, or repetition, or time then you are training wrong. Sometimes there is a need to focus only one parameter those are active rest days.

Power-Endurance is built through paying to attention all the parameters involved (# of Repetitions, Force required/involved, Distance covered, and Time). In essence we want to build the amount of work output by changing the power output involved. Each event has a different amount power and endurance required to complete the event task. Sometimes those events are very short in nature like the jumps and throws, but require high power and long warm up times and consist of multiple efforts while others such as long distance running require lower constant power-outputs with generally shorter warmup and cool down periods.

Power Endurance Durations:

1. Very-Short Duration (1-6s), for Sprinters, Jumpers, Throwers, and Multis with training that consists of sets of 1-3 reps with weights, medicine balls, jumps, bounds, throws, and acceleration and max Velocity sprint work.

2. Short Duration (6-15s), for Sprinters, Jumpers, Throwers, Mid-distance and Multis with training that consists of 3-8 reps with weights, medicine balls, jumps, bounds, hops, skips, throws, max Velocity sprint work, speed-endurance.

3. Short-Medium Duration (15-40s), for Sprinters, Multis, and Mid-distance with training consisting of
speed endurance, special endurance I, extensive, and intensive tempo running and lower intensity throws, jumps, hops, and skips.

4. Medium Duration (40-90s) for Long sprinters, Multi’s, and Mid-distance with training consisting of special endurance II and intensive tempo runs and lower intensity throws, jumps, hops, and skips.

5. Medium-Long Duration (90s-4 min) for Mid-distance and long distance athletes with training consisting of repetition or interval running to boost VO₂Max, generally 400m-1000m.

6. Long Duration (4-30 min) for Mid-Distance and long distance athletes with training consisting of longer intervals of 1K-1mile or repetitions of 1 mile to 3 miles or continuous tempo runs.

7. Very Long Duration (30+ min) for Long distance athletes with training consisting of extended continuous tempo runs.

If a coach is monitoring the change in power output in his “work capacity” training and those athletes are producing high power outputs then those athletes are adapting, but if those power numbers are not geared towards the event durations at which the athlete competes then progress will be slow in turning those adaptations into better performances.

In the next part, how to effectively measure power endurance or “work capacity” will be covered with some applications of how to apply this type of training specifically to a group of athletes. Please take the time to go over each of the links provided and start to figure out how and when to apply this training.