| Treadmills provided the easiest way to
burn calories of all other types exercise of machines. Researchers asked eight
male and five female young adults to exercise on six different types of indoor
exercise machines, including a cross-country skiing simulator, cycle ergometer,
rowing ergometer and stair stepper. They compared energy expenditure at ratings
of perceived exertion (RPE) levels of 11 (fairly light), 13 (somewhat hard) and
15 (hard), and found that subjects who exercised at an RPE of 13 burned
approximately 40 percent more calories per hour on the treadmill as compared to
the cycle ergometer, which produced the lowest energy expenditure.
Marketing research in 2001 showed that
the typical treadmill purchaser is likely to be female, 30-50 years old, and
mid-to-upper-income. 72% of all treadmill buyers are women, and 45% are over the
age of 45. However, treadmills are are increasing in popularity due to a
burgeoning senior population. While running has been a favoured activity of
Americans since the 1970s, walking has come into vogue in just the past five or
six years, in part because it's a low-impact exercise that older or less-fit
people can do easily. A treadmill lets you walk, as well as run. Walking and
running are activities that are simply easier to master than are other types of
exercise, such as biking, rowing, or using a stair-climber or ski machine.
Treadmills are probably the most
expensive piece of cardio equipment you can buy. Yet, they range in price from a
few hundred dollars to well over $5000. Decent quality home treadmills can be
bought for as little as $400. As a group, this type of machine either requires
the most maintenance or has the shortest life of all types of exercise
equipment. As of 2002 there are currently at least 36 different brands of
treadmills available.
There are still some cheap motor-less
treadmill models available that are driven by the user, utilizing inertia. They
are simple and more reliable; at least more reliable than the low end motorized
treadmills. The disadvantage of human powered treadmills is that they are slower
and more difficult to operate because if the exerciser begins to tire and slows
down, the belt gradually slows down too. Usually, non-motorized treadmills do
not have enough inertia to adequately keep the user moving at a constant pace,
so the user must actively maintain pace; just as if it were real unaccompanied
outdoor running.
OTOH, a motorized treadmill motivates
the user to keep up with the preset rate or programmed rates of the machine.
Powered models have electric motor drives that provide speed ranges as wide as
0-12 mph utilizing electric motors that are rated up to 3.0 HP continuous duty.
A brisk walking pace is about 4 mph, while at 12 mph you're clocking a
five-minute mile, roughly the speed of a world-class marathoner. One difference
in treadmill motors, which isn't always reflected in the product literature, is
whether the manufacturer lists horsepower in terms of continuous duty or peak
performance. Obviously this HP rating can be deceptive. If you weight more than
180 pounds, look for a motor that offers a minimum of 2.0 continuous-duty
horsepower. Most home units are DC, while commercial treadmills may have either
AC or DC motors. AC motors tend to be noisier and draw more power, meaning that
an AC treadmill will likely require a dedicated power line.
High quality frames are welded together
instead of using fasteners, and are usually made of steel or aluminium.
Two-ply belts are stronger and less
likely to curl at the sides than thinner one-ply belts. 20" wide belts are
common. Stay away from machines with belts narrower than 17". When testing a
treadmill in a store, the belt should not move from side to side from the impact
of moving feet.
Longer decks provide room for a more
comfortable stride than shorter surfaces. Size the machine for the height of the
user. Deck construction influences how smooth or hard the treadmill feels to run
on and how well it absorbs shock. You want a surface that gives a bit, but
doesn't bounce. Better quality decks are usually made of laminated wood, coated
with lubricants to minimize friction between belt and deck. Better decks are
also reversible, thereby doubling the life of the deck.
Treadmills for walking start at 0 or .5
and go up to around 5 or 6 mph, while those for jogging or running generally
start at 0, .5, or 1 mph and go up to 8-12mph.
Incline can range from a low of 2-4%, to
a high of 15%. Generally, the bigger the better; commercial-grade treadmills
often go as high as 25%. The most high-tech incline adjustment is the automatic
incline, which changes depending upon the exerciser's heart rate. For instance,
the Precor M 9.25 and M 9.45 treadmills measure heart rate via a wireless
monitor and automatically adjusts the percentage of incline to keep the person
within their target heart range. Other treadmills have electronic inclines that
can be altered by pushing a button on the console, while less sophisticated ones
have either a manual hand crank or other manual adjustment that has to be set
before starting to exercise.
Preset programs automatically change the
speed and/or incline of your workout and are a good way to alleviate boredom.
Some models also offer custom programs that essentially replay your favourite
workouts or enable you to duplicate the course of a known marathon or some other
race that you're training for, and a few will even adjust your workout according
to your pulse rate. A favourite feature for runners is the automatic warm-up
and/or cool down program, which helps reduce the risk of muscle pull.
An emerging technology that many
treadmill makers are adding is shock-absorption, to help spare the joints of
exercisers. Manufacturers use different techniques such as thicker (cushioning)
running belts, thinner running decks, rugs between the decks and belts, or shock
absorbers placed under the deck. Precor, for instance, has a patented "Ground
Effects" floating-bed technology (the bed sits on special springs). In the early
days, some of these floating-bed treadmills weren't so good. They felt as if you
were running on a trampoline, but they've improved the technology now.
You don't want to pay too much for a
treadmill, because they're like computers; more advanced features every year
make them obsolete before any part of them fails (unless they're low-end
machines). Even today's moderately priced machines are superior in both features
and reliability to the high end machines of 3 years ago. High-priced machines
will mean lower volume production, so they will also have high-priced
replacement parts and fewer distributors.
Treadmills are the highest maintenance
of all types of exercise equipment, so keep in mind lubrication and parts
replacement. Will you or a friend/relative/spouse be doing such maintenance
chores? I ask because it's a PIA to ship or transport the machine to a service
centre, and you don't want it to be out of service for a long time either.
Elliptical Cross-Trainer
A Primer for
Cardiovascular Exercise Machines
"Elliptical" is the hottest new addition
to the fitness vocabulary. This type of exercise machine is great for
stimulating your blood circulation and metabolism. Research comparing an
elliptical trainer to a treadmill, a stair stepper, and a cycle found no
significant differences in terms of oxygen consumption, calorie expenditure and
heart rate between treadmill running and the elliptical trainer.
Explanations
An ellipse is an oval shape, and this
roughly describes the path that the feet make when running. Actually, the path
the feet travel are a series of half-ellipses because the running motion of the
feet is intermittently stopped when they hit the ground, causing a rapid series
of impacts.
"Elliptical" cross-trainer exercise
machine is a misnomer. A more accurate description would be an "eggtical"
cycling machine, because of the egg-shaped path of the machine's pedals for a
complete cycle. The wide part of the egg-shaped path is generally on the side of
the pedal link where the crank is located, and the front-to-rear travel of the
pedals is always equal to the crank diameter. These machines allow your feet to
complete their noncircular path without impact. Like cycling, ellipticals offer
a no-impact exercise because the feet remain in contact with the pedals at all
times. Thus, individuals who suffer impact-related orthopaedic injuries may
benefit from elliptical cross-trainers. In addition, an elliptical machine
usually provides for movement of the arms, thereby spreading out the burning of
calories across a greater number of muscles and enabling a longer duration
(possibly easier) workout while toning more muscles. Another advantage of this
machine is that it allows the use of a backward-step motion. Though this
movement feels unnatural at first, it is beneficial since it works muscle groups
that don't ordinarily receive focused exercise. Consequently, an elliptical
machine combines some of the benefits of a step machine, a treadmill and a
stationary bike.
Design Differences
Ellipticals were introduced in health
clubs in 1995 and then home versions appeared in 1997. Originally the motion of
the better home elliptical machines mimicked that of running, so designs usually
had the crank to the rear of the pedal. However, since home treadmills continued
to gain popularity, most home elliptical designs have since evolved to become an
alternative to both stepper and cycle machines, mimicking a motion like that of
running uphill. These "climbing" type elliptical designs either have the cranks
or roller ramps to the front of the pedal links. Consequently, the popularity of
both steppers and cyclers has declined somewhat in recent years. Since steppers
require little floor-space, the trend toward home ellipticals that compete with
steppers is also manifesting itself in more compact elliptical machine designs.
Health club machines remain large but can usually provide a better quasi-running
motion than most home machines because the available stride is longer.
Elliptical models have a number of
design variations, so they each have there own unique feel because the shape of
their egg-shaped pedal paths are different or can be adjusted differently. Most
ellipticals can be driven in reverse motion, but some cannot. And some
ellipticals, including the most expensive health club models, do not provide for
arm motion.
There is an emerging trend started by
Icon Fitness to integrate leaf springs in the pedal links of their Nordic Track™
and ProForm™ brands for the purpose of reducing peak loads on the body. Leaf
springs do not eliminate impact; impact in elliptical machines was already
eliminated before leaf springs appeared. The design intent now is to soften the
forces on the body that accompany sharp changes in pedal direction for an
egg-shaped path. This is not a consideration in stationary cyclers because the
rotary motion of those machines' pedals is a circular (constant radius) path,
and so they cause no abrupt reactions to be felt on the body. Unfortunately,
metal leaf springs increase elasticity of the machine without imparting any
damping effects to compensate for increased vibration. Be aware that
elliptical machine designs without leaf springs already contain a significant
amount of elasticity, and these machines will shake at high speeds, which is
partly due to elasticity. The more elasticity that is built in, the more damping
that may also be required. However, currently there are no damping components
found in elliptical machines. One would think then that the newer more advanced
ellipticals with leaf springs would not be as stable at elevated speeds,
but compact ProForm™ models having roughly the same rear crank radius at the
pedal link: model 700 (leaf springs) and model 545s (no leaf springs).
There is no noticeable difference in vibration seen. Surprisingly, the
vibrations are not intolerable, and the machines stay in place on the floor
despite their equally small bases.
There are 2 subtypes of ellipticals. The
premium group has adjustable pedal path (usually via an adjustable inclination
ramp), and the other more economical group does not. Most models with the
adjustable pedal path have pedal links that are partially supported by rollers
that reciprocate on a ramp, and if these models have arm levers, then they will
also have linear bearing components (guide bushings) at the bottom of those
levers. These are additional parts that can wear out or become damaged, so this
roller-ramp group of machines is often (but not always) not as quiet in
operation as the simpler group. Commercial or health club ellipticals always
have adjustable pedal path and usually have one significant, albeit dubious
feature that is lacking in premium ellipticals for the home: that pedal path is
a motorized, on-the-fly, continuously adjustable feature. Conversely, there is a
simple new idea that has appeared in the latest ProForm and Nordic Track
ellipticals that provides an elegant way to accomplish adjustable pedal path:
adjusting the fore-aft location of the pedals on the pedal links. The pedals
simply have slotted holes for shifting the pedals either forward or backward for
less or more vertical motion in the path. Bolts clamp down the pedal to the
adjusted position. Frankly, I see the pedal path feature as a "set it and forget
it" adjustment that nobody would normally want to change their preference about.
It should be seen mainly as an adjustment to suit individual preferences for
different users. Because of the increased complexity and reduced reliability
(except for the slotted pedal models), adjustable pedal path should be
considered mainly if there will be more than one user of the machine and their
preferences are different. It is noteworthy though that an adjustable pedal
path can provide a monotony breaking benefit.
Oldie but Goodie
My own preference is the simple, quiet
ProForm model 485e (discontinued during 1999). Its relatively long, low pedal
path has a foot shuffling motion that is (was) one of the smoothest home
ellipticals to mimic running. Moreover, because the frame is adequately stiff
and pedal travel doesn't climb too high or too abruptly, the machine can be
sprinted at a high rate of speed without an intolerable level of shaking (if
done for short durations, or by a light-weight user). This sprintability not
only provides monotony breaking variation to the workout, but it is useful for
training the body to move quickly too; an athletic benefit that I found
particularly useful for tricky all-terrain downhill backcountry skiing. Newer
models of home ellipticals have shorter length pedal links, and/or ramping
beneath pedals, higher pedal travel, and smaller length frame bases; design
elements that effectively reduce the maximum speed. The 485e also provides for
arm motion, can be driven in reverse, and also has pedal links that are long
enough that the feet can be placed directly on the links at points just rear of
the pedals, thereby changing the path of the feet for greater vertical travel;
all beneficial for both minimizing monotony and exercising additional muscles.
Summary
Ellipticals, especially the models that
include arm motion, provide a versatile workout that can range in adjustable
resistance from easy to strenuous. Thus they are suitable for people of a wide
range of weight and strength, and the various models can be a good fit for
people of height 5'3" to 6'8". Good elliptical machines are appropriate for all
fitness levels, and are especially valuable to individuals with orthopaedic
problems that are aggravated by impacts. Moreover, I find ellipticals to be the
single best type of machine to train for downhill skiing on.
Suggestions
If you are non-athletic, then you will
probably be less demanding and thus find the greatest number of satisfactory
models to choose from. An athletic user should test each machine more rigorously
before purchasing; at maximum speed while at low/moderate resistance. Whatever
your athletic ability or fitness level, you should not purchase an elliptical
that you have not first tested yourself. With so many quiet, rigid elliptical
machines available, nobody should have to own a noisy one.
By Knack
Last revision June 22, 2002
Comments? Questions? E-mail
Many happy and productive
days ahead folks!
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