Physiological Capacity: Run Fitness - Part 2.

 In Part 1 we looked briefly at how your body's systems need to be able to work together to allow you to to get out to run, get to the start-line of a race and the, if it's your goal, to get to the finish-line as easily and fast as possible.

The Key…Optimal Fitness…

Optimal means ‘enough to get the job done’. No more, no less.

It doesn’t mean maximal, nor flat-out.

 

At rest, optimal means maintaining basal or minimal levels to survive.

During training, optimal relates to elevated or raised levels of performance to complete and achieve the goal(s) of the session, or a series of sessions (in a day, week, cycle, block and/or phase).  

In a race, optimal equates to maximal maintainable speed, and minimal managed fatigue.

Your fitness - bottom-line - is how well you are prepared to complete a given task.

Whether for podium, performance, participation, prestige or pride: completing your first 5 minute jog, a 5km Park Run, a cross-country or trail race, or marathon all require similar capacities, yet each requires different fine-tuning – that is, different (run-relative) fitness.

Being a “good” runner is relative. For example, breaking the 30, 25 & 20 minute barriers is “good” for many, and is a measure of progress for others. Running 5km in 15 minutes isn’t close to good at higher (age-dependent) levels, and won’t qualify you for state, national or international championships.

Of course, if your initial fitness is low (and you can’t run 5km to begin with), improving it will likely help you with the physical and mental capacity to attempt or complete longer (run) distances.

In this sense, optimal fitness is relative – to individuals, to event, and to age.

Your body lets you build fitness – or prepare you to complete (run) tasks - in two ways:

 

(1) responses: sudden, temporary changes in function caused by exercise. These functional changes diminish after exercise. Responses relate to acute, single bouts of exercise – a run, a training session, or a race

(2) adaptations: more-or-less permanent changes in structure and function following training – repeated or chronic bouts of exercise. They allow your body to respond more easily during and after future sessions. Adaptations bring about structural and functional changes that have effects at rest, and during sub-maximal and maximal efforts. Adaptations make your initial loads or sessions easier, and build your maximal aerobic power and capacity – or ability to go faster and/or longer.

Ultimately, to improve performance you need to challenge your mind, body and skills – challenge it’s plasticity, or ability to change or adapt.

You run. You run regularly. You train. Your body’s physiological systems will alter their function (respond) in anticipation of, during and after each session. Over time, through repeated sessions their structure alters (thanks to nifty mechanical, chemical and genetic signaling systems) and, unless loaded inappropriately, function improves. Stop training and, at different rates, the improvements return towards their initial levels – you detrain.

Regular running optimises your body’s function in relation to (future) running, and maybe a few other tasks. Specific training optimises it for specific events and performance levels.

Depending upon your starting point, time-frames and goals optimizing your running (and training) can be see as optimising your energy and work.

These are the focus of part 3.

Physiological Capacity and Run Fitness - part 1

Ever wondered what goes on when you run? When you race?

Or how your body responds (to each repetition, set or session) and adapts (to multiple sessions - called training) to get better?

This is the first of a multi-part series on general physiological aspects of endurance run performance.

The next series will investigate specific physiological aspects of endurance (run) performance and how to improve them.

Getting to a run-race start-line is one thing. Negotiating getting to the finish-line as fast or as easy as possible is another.

An official entry, effective training, sound health and the right gear will get you to the start-line. Getting to the finish-line tests your health, training, good fortune, drive and fortitude.

How fast you get there will test your physical (and mental) capacity, and fitness. So too the course demands (duration. hills, surface, turns) and environment (heat, humidity, wind, smog/pollution, sun), your experience, and smart choices about pacing and managing fatigue.     

Your racing capacity is ultimately determined by your endurance training background, racing history, and genetic make-up – your unique physiological, mechanical and mental passport. And, to the extent you’ve developed the supporting bodily systems.

All Systems Go…

To get you to the line, red-lining, over the line, and lining up again requires a large - chiefly under-appreciated - complex and coordinated effort by all your bodily systems ...

System*	Main players	Important tasks
respiratory	·      lungs & airways ·      breathing muscles o   diaphragm o   intercostals	·      moving air in and out of the body ·      exchanging gases (mainly oxygen, carbon-dioxide) and water vapor with environment ·      speech
circulatory (& lymphatic)	·      heart ·      blood vessels ·      blood – cells, plasma	·      transport of nutrients, gases, chemical messengers (hormones), waste products, and protective bodies around the body ·      body temperature management ·      maintaining acid-base balance
integumentary	·      skin ·      hair, nails ·      (sweat) glands ·      receptors	·      barrier to foreign substances ·      prevent loss of excessive fluid from cells ·      temperature regulation ·      sensory information – pressure, hot, cold, pain ·      communication – touch, emotion
nervous (and senses)	·      brain ·      nerves ·      specialised organs ·      chemical transmitters	·      relationship with outside environment ·      regulation of other systems ·      abstract thought, learning & memory, reason, emotion ·      integration – judgments made from lots of information ·      movement – with muscular
Endocrine (hormonal)	·      hormones ·      special glands such as: adrenal, reproductive, pancreas,	·      works very closely with other systems, particularly nervous, digestive, reproductive ·      transport of chemical messengers – hormones ·      regulate growth, nutrient use & storage, adjustment of water & electrolyte balance ·      metabolic rate
digestive (& urinary)	·      stomach ·      intestine(s) ·      liver ·      pancreas ·      kidneys ·      bladder	·      breakdown of large food particles ·      absorption of macro- and micro-nutrients ·      absorption of water ·      formation of blood proteins ·      storage site for vitamins & minerals ·      carbohydrate storage & metabolism ·      detoxification ·      maintain blood sugar levels ·      maintain normal composition of body fluids ·      removal of waste
skeletal	·      axial o   skull &vertebrae o   sternum & ribs ·      appendicular o   shoulder girdle & arms o   pelvic girdle & legs ·      joints	·      support: tissues, organs & muscle attachments ·      movement: joints, muscles ·      protection of vital organs ·      blood cell formation ·      storage of minerals
muscular	·      muscles ·      tendons ·      specialised receptors	·      posture, mobility and stability: static, dynamic ·      movement ·      heat regulation ·      assist blood flow
* the direct system(s) involved with reproduction, development, and genetic control & inheritance aren’t included

To run, function or perform at your best, you and all bodily systems must function optimally. 

The systems have different yet complex interactions within and amongst themselves:

(a) to keep you up and about – alive

(b) for growth & development, repair & recovery

(c) to cope successfully with the daily stress and stressors of your environment, lifestyle and training (d) to protect against invaders and failing systems, and

(e) pass on your genetic passport

Part 2 will explore Optimal Fitness for running.