Mechanics

Professor Edward M Winter

Welcome to today’s Webinar

Edward M Winter BEd MSc PhD DSc FBASES FafPE

Professor of the Physiology of Exercise

Terms and Nomenclature to Describe Exercise

Mechanics

Professor Edward M Winter

About today’s webinar

Today’s webinar is part of a series being produced jointly by the British Association of Sport and Exercise Sciences (BASES) and Human Kinetics.

It scheduled to last for about an hour and will be recorded and made available for download and playback.

You will automatically receive an e-mail containing a link to the recording when it is available. All microphones and phone lines are muted so we ask that you submit questions by typing them into the question box, located in the lower right-hand corner of your screen and click “send.”

We’ll collect any questions sent throughout the presentation and Edward will answer as many as possible during a Q&A segment at the end of the session.

Mechanics

Professor Edward M Winter

About today’s speaker

Professor Winter was a founder member of BASES, co-designer of the Association's accreditation scheme and until recently, was accredited both for research and scientific support in physiology. He has authored more than 200 publications, been involved in the review of more than 2000 manuscripts and abstracts for all of the major journals in sport and exercise, has extensive experience of supervising and examining DSc, PhD, MPhil and MSc-by-research candidates and still plays county-standard squash. He is resolute in his determination to ensure that sport and exercise science upholds the principles and practices of science.

Sport and Exercise Science

The scientific study of factors that influence our ability to perform exercise

Quantify the ability to perform exercise Correctly apply mechanical constructs Frequently this does not occur In spite of Newton and the laws of physics In spite of the SI

Classical mechanics

Definitions of Exercise

Repetitive, purposeful movement Fails the first characteristic of science i.e.

observation In sport, movement can be deprecated In activities of daily living, isometric muscle

actions occur deliberately and purposely

Definition of Exercise

A potential disruption to homeostasis by muscle activity that is either exclusively or in combination, concentric, isometric or eccentric.

Function of Muscle

Muscle contracts No it doesn't!

Function of Muscle

Muscle contracts No it doesn't! Muscle activity

Function of Muscle

Irrespective of the type (skeletal, cardiac or smooth):

The function of muscle is to exert force It does so by attempting to shortenHence, concentric, isometric or eccentric

activity/actions

Concerns

Adamson and Whitney (1971) Knuttgen (1978) Winter Winter and Fowler (2009) Knudson (2009)

Concerns

Force Work Velocity Power Efficiency Work-energy and impulse-momentum

approaches

Concerns: mass and weight

Mass: amount of matter (kg) Weight: the force that that mass exerts

under prevailing gravity (N)

Concerns: velocity and speed

Velocity: a vector (implies magnitude and direction)

Speed: a scalar quantity (only magnitude)

Concerns: work

Mechanical work is done when a force moves its point of application such that some resolved part of the displacement lies along the line of action of that force

Force (N) x distance (m) Nm: joules (J) Workload (abomination) Isometric muscle activity . . .

Concerns: power The rate of doing work Not the product of force and

velocity Not "work rate" (colloquial) Unit: watt (W) James Watt (1736-1819) Horsepower (1782) 33,000 (32,572) ft.lb/min 550 ft.lb/s 735-750 W

Concerns: power

Concerns: power

Concerns: work-energy or impulse-momentum?

Newton II Changes in momentum Projectiles Impulse (Ft) Endurance Total energy i.e. sum of translational and rotational

kinetic energies, potential energy, heat, acoustic . . .

How hard is someone exercising?

Intensity All forms of activity (m, s, N, Nm, m·s-1, W) Physiological responses to imposed

demands (%) Exercise performed (%)

Domains of Intensity

Moderate, heavy, very heavy, severe and extreme

Based on physiological responses to imposed demands

Critical power

50 years old A limit of tolerance to exercise Isometric muscle activity . . . Running, swimming etc. . . . Velocity and speed Cycling - internal and external components . . .

Sport and Exercise Science

The term "critical power" has at best limited application and should be abandoned

The term "critical intensity" applies to all forms of exercise, adheres to principles of classical mechanics, the SI and hence principles of science and should be used instead

Mechanics

Professor Edward M Winter

Any Questions?We have received quite a number of questions and we will try and answer as many as possible in the time remaining.

I’ll keep the Q & A session going as long as is practical and we still have an audience to address.

Any that remain unanswered will be forwarded to Edward and he’ll try and email you a reply in due course.

Mechanics

Professor Edward M Winter

ThanksThank you to everyone for joining us today and thanks also to Professor Winter for what I’m sure you will agree was a great presentation.

Please take a few moments when your webinar window closes to complete a short survey on today’s webinar – we appreciate your feedback as it helps us continually improve our webinars.

We will email everyone a link to the recording of today’s presentation, so you can view it yourself or pass it along to friends or colleagues.

Thank you again for your participation today and I hope you will join us on Wednesday, 23rd October at 9.00am, when Vicki Aitken will present “The Playing Attitude: Why we can’t think technically if we want to perform at our best.”.

Thanks and enjoy the rest of your day.