Transcript Fitness Applications: Introduction (1)

Fitness applications - objectives
• To develop a knowledge and understanding of:
• The role of biomechanics in fitness programing
• Fitness objectives and conditioning principles
• Biomechanics principles in the design and conduct of resistive,
aerobic, and flexibility exercise
• Design, evaluation, and selection of resistive and aerobic
exercise equipment
• Exercises and exercise equipment of questionable value
Fitness Applications: Introduction
• References (on reserve):
– Kreighbaum & Barthels (1996). Biomechanics: A qualitatibve approach
for studying human movement. Chapter 8 – pp 245-271
– Baechle (2000). Essentials of Strength Training and Conditioning. Ch 3
• Role of Biomechanics in Fitness Programming
– Anatomical-mechanical analyses of exercise design (What exercises to do?)
– Anatomical-mechanical analyses of exercises (Technique, or how to do it?)
– Mechanical analysis of exercise equipment (Design and selection)
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Objectives of most fitness programs are to improve:
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Muscular Strength
Skeletal strength
Muscular Endurance
Flexibility
Cardiorespiratory Endurance
General fitness conditioning
principles
• Important conditioning principles:
– Progressive overload
– Specificity of training – SAID principle
• movement pattern, joint position, speed, type of contraction
• Remember which aspect of fitness you are working
on and apply the overload and specificity principles
appropriately
• What is the stimulus for improvement of each
fitness element?
Biomechanics of Resistive exercises
• Factors affecting force
application
– Force-velocity relationship
– Strength-joint position
relationship (combination of
angle of pull and force/length
relationship)
• Should we provide the same
degree of overload
throughout the movement? If
so, how do we do it?
Use of Cams in Ex Equipment:
Why?
Recommended forearm flexion exercise –
Variable resistance, NATURALLY!
Effect of speed on torque during exercise:
Torque = Wd + MOI x ang acc
Recommended Extension Exercise –
variable resistance, NATURALLY!
Effect of speed on torque during exercise:
Torque = Wd + MOI x ang acc
Developing Muscular Strength
• Muscular Strength - ability of segment to exert force (MVC)
– Overload stimulus is tension (use resistance equal to or greater than 10 RM )
– Factors affecting force application:
• Force-velocity relationship
• Strength-joint position relationship (combination of angle of pull and force/length
relationship)
– Focus on fundamental movements, antigravity musculature, and proportionate
development
– Specificity principle applies to:
• body position
• speed and type of contraction
– Concentric
– Eccentric
– Isometric
• range of motion
• movement pattern
• pre-contraction stretch condition (plyometrics)
Developing Muscular Endurance
• Mucular Endurance- ability to repeat or sustain
submaximal contractions
– Overload stimulus is work intensity
– Use load approx 60% of max strength, or < 10 RM
– Focus on fundamental movements, antigravity musculature, and
proportionate development
– Specificity principle applies to resistance, body position, speed,
cadence, ROM, and total number of reps
• Cardiorespiratory Endurance - Aerobic capacity
– Overload stimulus is VO2 max, Cardiac output, or Heart Rate
– Repetition and resistance relative to muscular strength/endurance
are important
– Remember specificity principle regarding gravity, muscles
involved
Developing Skeletal Strength
• Overload stimulus is strain (normalized deformation )
• Remember 4 loading modes
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Compression
Tension
Torsion
Shear
• Exercise in gravitational environment and emphasize
weight bearing and resistive exercises
• Skeletal strength is developed concomitantly with
muscular strength development
• The best way to prevent osteoporosis is to build up bone
mineral content (BMC) during childhood, adolescence and
early adulthood
Sample Resistive Exercise Program
• Basic Program - required
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Squat with heel raise
Trunk curl (goal is 30 reps)
Bench press
Sit or bent row
Upright press
Pull downs or chins
Optional exercises
– Back extension from prone position
– Forearm curl
– Forearm extension or dips
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Note: This program incorporates the principles of bilateral and agonisticantagonistic balance and focuses on muscular strength and endurance development
of the antigravity musculature. At least two sets (one with light weight for warmup), and preferably three sets, of each exercise should be completed at 10-15 RM.
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What exercises would you change or add?
Understanding questions related
to biomechanics of fitness
• Devise a series of exercises for strengthening the triceps brachii.
Recall its functions at both joints, its three proximal attachments, its
possibility for length-tension adjustments, and its potential for active
and passive insufficiency.
• What is the overload stimulus for development of each of the
following fitness elements? (1) Muscular strength, (2) muscular
endurance, (3) flexibility, (4) bone strength, (5) cardiorespiratory
endurance.
• Explain two ways that resistance changes during the movement of a
gravity-dependent exercise using free weights or the body as the
resistance.
• What is a variable resistance exercise machine? What is the reason
for their design and use?
Understanding questions
• Explain why it is so important to do gravity-dependent
resistive exercises slowly.
• Compare the difficulty of doing straight-leg situps with (a)
the hands beside the neck, (b) the arms crossed over the
shoulders, and © the arms at the sides. Explain the
differences in difficulty in terms of motive and resistive
torques and muscle groups being used.
• Name a flexibility test that you have taken in the past that is
biased for or against people with different body segment
proportions.
• Why is the timed situp test with the feet anchored ill
advised?
Criteria for Resistive Equipment Selection
• Can you apply specificity principles appropriately?
– Type of contraction, movement pattern, speed
– Carryover to living in gravitational environment?
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Is resistance enough to accomodate your strength?
Does it fit different sized people?
Is it safe?
Is it uncomplicated to use (user friendly)
Is there scientific evidence to support manufacturer’s
claims?
• Does the equipment follow a normal neuromuscular
pattern?
• If variable resistance, does resistance follow normal
strength-position curve?
• Does it have motivation-enhancing features?
Approximate Costs of Resistive Ex
Equip
• Free weights
– Benches $660; dumbbell set $1,300; Rack for dumbbells
$585; Olumpic weight set $1,650
• Plate loaded weight machines - $1,500-$1,700
• VRI station (variable resistance one axis) - $1,700$3,900
• VRII station (variable resistance, 2 axes) - $2,300$4,000
• Isokinetic (accomodating resistance) - $10,000
• Computer-controlled - $20,000
Relevant Questions for, or Criteria, for Aerobic
Exercise Type and Equipment Selection
• Exercise modes include walking, running, stair climbing, bicycling, rowing, skiing,
swimming
• Equipment simulates some activities using large proportion of total body
musculature
• Evaluate each mode relative to the following criteria
– Degree of overload on cardiorespiratory system
– Relevance to fundamental movements and ADL’s
– Proportion of total body musculature involved
– Degree of compressive stress on femoral head and lumbar vertebral bodies (sites
of most osteoporotic fractures)
– Compressive stress on patella and knee joint
– Range of motion and torque at hip, knee, and lumbar spine
– Motivational features (comfort, user friendly, feedback, RPE)
– Likelihood of continued usage
– Cost
– Other?
Comparison of Aerobic Ex Modes
Comparison of Aerobic Ex Modes
Comparison of Aerobic Ex Modes
Approximate Cost of Aerobic Exercise
Equip at Rec Complex
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Rowers
$1,000
Stationary Bikes (upright & recumb) $2500
Elliptical exercisers
$3200
SciFit Total Body Crosstrainer
$4000
Stairstepping machines
$4500
Hybrid – Cybex Arctrainer
$5000
Treadmills
$5000-$8000
Questionable exercises
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Hyperextended back
Good morning exercise
Straight leg deadlift
Deep knee bends beyond thighs parallel
Ballistic rotation movements of spine
Behind neck press
Bouncing and jumping with one-legged landings
Questionable exercises:
It depends on
how you do it!
Abdominal
Exercises:
When knees are straight, hip
flexors initiate the situp
movement by forward rotation
of the pelvic, exaggerating the
posterior lumbar curve.
Anchoring the feet enables hip
flexors to contribute to the
situp, lowering abdominal
muscle activity.
What is the effect of the inclined
board?