Which aerobic exercise mode is best?

Compare each mode relative to the following criteria- Degree of overload on cardiorespiratory system (Consumer

Reports Mar 2002, p 13)(Fitness Management August 2000, p 1-3)

- 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:HR while exercising at similar RPE

Comparison of Aerobic Ex Modes:VO2 while exercising at similar RPE

Comparison of Aerobic Ex Modes: Vertical Ground Reaction Force

Comparison of Aerobic Ex Modes:How long does it take to burn 200 calories?

Consumer RepMarch 2002, p 13, citing data from MSSE August, 2001.19 subjects exercising at similar RPE’s

Comparison of Health Rider and Treadmill on VO2 Max

From website: http://www.isu.edu/departments/dpot/research/healthrider.html

Methods:- Max ex bouts on each exercise type- 15 college males & 15 college females- Measured several variables indicative of overload on

cardioresp system- VO2, VE, RER, Resp Rate, METS, HR, ratio of VO2/HR

Results:- Treadmill produced superior results for all variables,

including VO2 max (53.8 ml/kg/min vs 38.1 ml/kg/min)

Approximate Cost of Aerobic Exercise Equip at Rec Complex

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

Cross-country ski simulators

Advantages- Potential for high energy expenditure- Good off-season training for skiing competition- Can talk or listen or watch- Non-impact

Disadvantages- Not easy to learn to use- Need to develop skill- None have capability to convert exercise effort into

repeatable intensity- Most models have poor feedback on work intensity

Stationary cycles Advantages

- Inexpensive, compact, portable- Can listen, talk, and watch- No heel-strike forces (.6 g)- Good feedback on work rate and energy expenditure- Easy to use

Disadvantages- Sore butt can be a problem- Boring- Only works the legs – those with poorly conditioned leg muscles

will fatigue quickly- Low carryover to ADL’s- Higher RPE than treadmill or ellipticals

Treadmills Advantages

- Good carryover to locomotion- Can get good aerobic overload- Can control speed and slope and can be programmable and

reproducible- Weight bearing – high GRF’s- Easy to learn how to use- Greatest incidence of use in homes- Lower RPE than most other aerobic ex machines

Disadvantages- Expensive- Impacts and high VGRF may exacerbate lower extremity problems- Not portable and compact- Noisy

Hybrid: Elliptical Exercisers Advantages

- Can get good aerobic overload- Cheaper than treadmills & stepping machines- Lower RPE for same workout intensity - Low impact – less stress on lower extremities while allowing a weight-bearing

exercise- Easy and safe to use- No motor- less noisy than treadmills- Can control speed and slope and can be programmable and reproducible

Disadvantages- Low impact and lower VGRF than treadmills- Movement is less similar to normal locomotion pattern than treadmills- Many models do not allow sufficient stride length for taller people

Rowing machines Advantages

- Uses large muscle mass than cycling- Greater energy energy expenditure than cycling- Can talk or listen or watch- Non-impact- Cheap- Easy to learn how to use

Disadvantages- Limited capability for incrementing and reproducing

workload- Untrained rowers may fatigue quickly- Low carryover to ADL

Stepping machines

Advantages- Low impact - Can talk or listen or watch- Easy to learn how to use- Relatively inexpensive

Disadvantages- High knee torque and patellar compressive forces

(hard on knees)- Minimal trunk and upper body involvement- Can be boring

Exercise Equip of Questionable Value

Devices which purport to provide great benefits with little effort

Devices to vibrate, melt, or massage away fat Stretching, pulling, or pushing devices Wearing or carrying weights Others that you can think of?

Other websites on exercise equipment

Source for exercise equipment:- Fitnessquest home page- http://www.exerlopers.com/

Sites including exercise equipment research :- ISU Dept of OT- Precor research page- Sportscience journal

Methods for Resistive Equipment Selection

Apply relevant scientific principles to evaluate claims- Biomechanical- Physiological- Psychological- Use it yourself at conferences or health clubs

Product reviews in fitness magazines (Club Industry, Athletic Business, Fitness Management)

Try it yourself and take a tall or short person with you Consult with experts who supervise its use, or other

professionals (e.g., professors in area of expertise) Look at research available, if any Evaluate quality of research

- Who sponsored research?- Peer-reviewed presentation?

Relevant Questions for Resistive Equipment Selection (Criteria)

Can you apply specificity principles appropriately?- Type of contraction, movement pattern, speed- Carryover to living in gravitational environment?

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?

Resistive Exercise Equipment Simple and handy devices (plastic bottles, rubber tubing,

springs)- adv - cheap, convenient- disadv - no versatility in direction, force, speed

Constant resistance training devices (free wts, body wt) - adv – convenient to use, cheap, balance needed, portable, motivation - disadv - safety, inconvenient to change wts, no versatility indirection,

speed Gravity-dependent resistance machines (circular pulleys)

- adv - safety, convenient to change wts, versatility in force direction, motivation

- disadv - cost, balance not required

Gravity-dependent Resistance Wt Machine

Concentric and eccentric contraction of agonists only!

Resistive Equipment (cont’d)

Variable resistance wt machine (CAMS or roller on bar)- adv - variable resistance as well as direction of force app, motivation- disadv - cost, no versatility in speed

Isokinetic devices (same speed)- Adv - speed specific, vary force during movement (great for rehab)

- Disadv – most devices involve only concentric contractions,

motivation, cost Computer-assisted devices (can control either speed or

resistance) - adv - variable resistance & speed, motivation, permanent record - disadv - cost

Variable Resistance

Weight Machine

Concentric and eccentric contraction of agonists only!

ComputerizedExercise Machine

Agonists and antagonists Concentric contraction only!

Pneumatic Resistance(air, two-way)

Agonists and antagonists Concentric contraction only!

Isokinetic (accomodating) Resistance (one-way)

Agonists concentric contraction only!

Hydraulic Resistance

Agonists and antagonists Concentric contraction only!

Elastic Resistance

Bowflex: Soloflex:

Agonists only, concentric & eccentric contraction

Exercise Equipment of Questionable Value

Devices to vibrate, melt, or massage away fat Stretching, pulling, or pushing devices Wearing or carrying weights Evaluation of several types of ex equip:

- American Council on Exercise Research Page- Fitness Equipment: Index- Exerlopers Fitness Systems - Home Page- Electrical Muscle Stimulator

Source for purchasing exercise equipment:- Fitnessquest home page

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