Looking and feeling young:
A recent study published in the January 2010 issue of
Journal of Aging and Physical Activity
showed that consistent aerobic training had a positive effect on muscle mass, power, and strength, which could keep people active and independent for up to two decades longer than a sedentary lifestyle.
Types of Cardio
Aerobic exercise has almost an unlimited number of forms. Typically, it is performed at a moderate level of intensity over a relatively long period of time, such as by running a long distance at a moderate pace. If you include a few sprints in this run, you will be performing both aerobic and anaerobic exercise. Cardio exercises include running, swimming, racquetball, tennis, bicycling, rowing, resistance training with no or very short rest periods, calisthenics, martial arts, stair climbing, jumping rope, cross-country skiing, and fencing—the list goes on and on and includes any activity that increases heart rate and oxygen uptake for a prolonged time period.
METs Matter
Obviously, not all exercises are created equal. Each type of aerobic exercise uses a different amount of energy. In addition, all exercises can be performed at different intensities, and for different durations. In order to figure out what you need to do in order to maximize the time you spend exercising and get the most health and fitness benefit from the exercises you choose, you’ll be using a standard list of metabolic equivalents, or METs.
A MET is a measure of how much oxygen we use in a minute when we are just sitting or lying down. It’s another expression of VO
2
. Or, stated another way, it’s the base amount of oxygen we need each minute to just stay alive. It’s essentially the same for everybody—3.5 ml O
2
per kg body weight per minute. A 2-MET activity requires twice the metabolic energy expenditure of sitting; three METs require three times as much energy as sitting, and so on. The maximum METs (METs
max
) healthy people can achieve are in the range of 7.1 METs to 22.9 METs, depending on a variety of physiological parameters, including age, sex, genetics, overall health, and fitness level.
WHICH IS THE BEST WAY TO LOSE FAT—MORE EXERCISE OR FEWER CALORIES?
The only way to lose body fat is to achieve a caloric deficit by decreasing intake of food and by burning more calories through exercise. Aerobic exercise is a great way to achieve a caloric deficit. It does not trigger the starvation response, but it increases metabolic rate, increases all of the fat-burning enzymes and hormones, targets body fat rather than muscle tissue for energy sources, and increases the sensitivity of all cells to insulin so that carbohydrates are burned for energy and stored as glycogen rather than being stored as body fat.
Your maximum exercise capacity or METs
max
plays an enormous role in your overall health and well-being. A recent study determined that men on average lose 4 to 7 ml/kg/min (1 to 2 METs) in their maximum oxygen consumption every 10 years of their life—unless they do something about it! Men whose maximum exercise capacity is less than five METs are twice as likely to die as those with a maximum exercise capacity of more than eight METs. There is a nearly linear reduction in risk of dying with increasing levels of METs
max
(fitness). If you have heart disease and train to a point where you can achieve 10 METs, your prognosis is as good as that of those who undergo bypass surgery. If you can achieve 13 METs you have an excellent prognosis. Sixteen METs make you an aerobic master athlete; at 20 METs, you are an elite aerobic athlete.
In healthy men and those with cardiovascular disease, peak exercise capacity is a stronger predictor of death than risk factors such as hypertension, diabetes, obesity, heart arrhythmia, high cholesterol, and even smoking. Poor fitness is the deadliest risk factor of all! With each 1-MET increase in your exercise capacity, there is a 13 percent improvement in your chances of not dying this year. Men who can achieve exercise capacities of greater than 10 METs have a 70 percent lower risk of dying than those who achieve less than five METs.
Exercise capacities of 10 METs are the predicted levels for a healthy, fit man younger than 43 years old. The goal for each and every one of us should be to have an exercise capacity of at least 10 METs.
The table below gives examples of the energy cost in METs for various activities. This can give you a good idea of what you need to do to achieve the goal of having an exercise capacity of at least 10 METs.
METABOLIC EQUIVALENTS (METS) FOR VARIOUS ACTIVITIES
CONDITIONING EXERCISE
Bicycling <10 mph, leisure, to work, or for pleasure
4.0
Bicycling, 10–11.9 mph, leisure, slow, light effort
6.0
Bicycling, 12–13.9 mph, leisure, moderate effort
8.0
Bicycling, 14–15.9 mph, racing, or leisure, fast, vigorous effort
10.0
Calisthenics, heavy vigorous effort
8.0
Calisthenics, home exercise, light or moderate effort, general
3.5
Circuit training including some aerobic movement with minimal rest
8.0
Weight lifting, power lifting, or body building, vigorous effort
6.0
Health club exercise, general
5.5
Stair-treadmill ergometer
9.0
Rowing, stationary ergometer, general
7.0
Ski machine, general
7.0
Stretching
2.5
HOME REPAIR
Automobile body work
4
Automobile repair
3
Carpentry, general workshop
3
Carpentry, outside house, building a fence
6
Cleaning gutters
5
Excavating garage
5
Hanging storm windows
5
LAWN AND GARDEN
Carrying, loading, or stacking wood, loading/unloading or carrying lumber
5
Chopping wood, splitting logs
6
Clearing land, hauling branches, wheelbarrow chores
5
Mowing lawn, general
5.5
Planting seeds, shrubs
4.5
Shoveling snow, by hand
6
Trimming shrubs or trees, manual cutter
4.5
Gardening, general
4
Picking fruit off trees, picking fruits/vegetables, moderate effort
3
OCCUPATION
Building road (including hauling debris, driving heavy machinery)
6
Building road, directing traffic
2
Carpentry, general
3.5
Carrying heavy loads, such as bricks
8
Carrying moderate loads up stairs, moving boxes (16 to 40 pounds)
8
Construction, outside remodeling
5.5
Electrical work, plumbing
3.5
Farming, baling hay, cleaning barn, poultry work, vigorous effort
8
Farming, taking care of animals (grooming, brushing, shearing sheep, assisting with birthing, branding)
6
Firefighter, general
12
Firefighter, climbing ladder with full gear
11
Firefighter, hauling hoses on ground
8
Forestry, ax chopping, fast
17
Forestry, carrying logs
11
Masonry, concrete
7
Masseur, masseuse (standing)
4
Skin diving or SCUBA diving as a frogman
12
Police, making an arrest (standing)
4
Shoveling, digging ditches
8.5
Truck driving, loading and unloading truck
6.5
Typing, electric, manual or computer
1.5
Using heavy power tools such as pneumatic tools (jackhammers, drills, etc.)
6
Walking, pushing a wheelchair
4
Walking, 3.5 mph, briskly and carrying objects less than 25 pounds
4.5
Walking or walking downstairs or standing, carrying objects about 25 to 49 pounds
5
RUNNING
Jog/walk combination (jogging component of less than 10 minutes)
6
Jogging, general
7
Running, 5 mph (12 minutes/mile)
8
Running, 6 mph (10 minutes/mile)
10
Running, 7.5 mph (8 minutes/mile)
12.5
Running, 10 mph (6 minutes/mile)
16
Running, 10.9 mph (5.5 minutes/mile)
18
Running, stairs, up
15
SEXUAL ACTIVITY
Active, vigorous effort
3–4
General, moderate effort
2–3
Passive light effort, kissing, hugging
1
SPORTS
Badminton, social singles and doubles, general
4.5
Basketball
8
Billiards
2.5
Bowling
3
Boxing, punching bag
6
Boxing, sparring
9
Fencing
6
Football, touch, flag, general
8
Football or baseball, playing catch
2.5
Frisbee playing, general
3
Frisbee, ultimate
8
Golf, general
4.5
Judo, jujitsu, karate, kick boxing, Tae Kwon Do
10
Orienteering
9
Paddleball, casual, general
6
Racquetball, casual, general
7
Rock climbing, ascending rock
11
Rock climbing, rappelling
8
Rope jumping, fast
12
Rope jumping, moderate, general
10
Rope jumping, slow
8
Rugby
10
Shuffleboard, lawn bowling
3
Rollerblading (in-line skating)
12
Soccer, casual, general
7
Softball or baseball, fast or slow pitch, general
5
Squash
12
Table tennis, Ping Pong
4
Tai chi
4
Tennis, singles
7
Tennis, doubles
6
Trampoline
3.5
Volleyball
4
Volleyball, beach
8
WALKING
Backpacking
7
Downstairs
3
Hiking, cross-country
6
Bird-watching
2.5
Marching, rapidly, military
6.5
Pushing or pulling stroller with child or walking with child(ren)
2.5
Pushing a wheelchair, nonoccupational setting
4
Race walking
6.5
Rock or mountain climbing
8
Upstairs, using or climbing up ladder
8
Walking, 2.0 mph, level slow pace, firm surface
2.5
Walking for pleasure
3.5
Walking the dog
3
Swimming laps, freestyle, fast, vigorous effort
10
Swimming laps, freestyle, moderate or light effort
7
Water aerobics, water calisthenics
4
WINTER ACTIVITIES
Moving ice house (set up/drilling holes, etc.)
6
Skating, ice, 9 mph or less
5.5
Skating, ice, general
7
Skating, ice, rapidly, more than 9 mph
9
Skating, speed, competitive
15
Skiing, general
7
Snowshoeing
8
APPRECIATING VALUES OF METS
MAX
Super Athlete
National Athlete
IM Athlete
Fit Man
Average Man
23+ METs
18.6–22 METs
14.3–18.6 METs
10–14.3 METs
5.7–10 METs
Using Heart Rate to Estimate Potential Energy Expenditure
Heart rate (or pulse rate) provides the most valuable information about your level of fitness and your response to exercise. For each of us, heart rate and oxygen uptake are directly related throughout a broad range of aerobic exercises. If you know this relationship, you can use your heart rate to estimate your oxygen uptake while you are training. This is important information you will need to make sure you are training at a level of intensity that will allow you to achieve improved cardiopulmonary health, aerobic conditioning, and fat loss.
HR
max
is the highest heart rate you can safely achieve. The most accurate way of determining your individual maximum heart rate and how it relates to your oxygen consumption is to have a cardiac stress test by a cardiologist or exercise physiologist.