Walkers do not lose contact with the surface upon which they are traversing. A walker’s advancing or striding foot lands before the rear foot leaves the ground. The rear foot supports the weight of the body while the advancing foot is swinging forward. During a brief period, both feet are in contact with the ground simultaneously. At slow speeds the normal walking gait, with its relaxed arm swing, is an efficient form of locomotion that actually conserves and reduces energy expenditure. To some extent this is a drawback to developing physical fitness, but research indicates that walking efficiency decreases and energy expenditure increases as walking speed increases.
The faster you walk, the more calories you burn. This is not the case with jogging, in which speed is irrelevant. Jogging a 10-minute mile is much more comfortable, yet burns about the same number of calories as jogging a 6-minute mile.
Body weight also has an impact on energy expenditure for both walking and jogging, as these activities are of the weight-bearing type. Weight-bearing activities are any sustained exercises performed against the force of gravity. By way of comparison, walking and jogging are classified as weight-bearing, whereas swimming and stationary cycling are non-weight-bearing.
Walkers can use certain techniques to increase the aerobic challenge as well as the energy they expend per workout. The simplest way to accomplish both is to quicken the pace, but this must be done slowly, progressively, and systematically. If you have only 30 minutes to exercise, a slightly faster pace will allow you to cover more distance, it will improve your aerobic capacity, and it will burn more calories.
A second option is to use interval training techniques, in which the pace is alternated between your regular speed and a faster speed. The faster speed should allow you to talk, but only a few breathless words at a time. You should integrate faster walking speeds systematically and slowly. In the beginning the ratio of your regular speed to the faster speed should be about three to one. For example, if you can sustain the faster pace for 1 minute, you should sustain the regular pace for 3 minutes. The cycle should be repeated until you cover the required distance or the time allotted for the workout ends. As you become more physically fit, you should increase the time spent walking faster and decrease the time spent walking slower until they eventually even out.
Studies have shown that the average preferred walking speed of healthy young adults is 3.24 miles per hour (mph), and healthy elderly people (about 70 years of age) prefer to walk at 2.9 mph. Physically active people seem to prefer faster average walking speeds of 3.5 to 3.7 mph. Speeds that are measurably faster than the average for each group would constitute the faster walking intervals for each.
The energy expenditure of walking also can be increased by swinging the arms vigorously or by swinging handheld weights. A word of caution: Vigorously swinging hand-held weights can result in shoulder soreness or injury. It also might lead to abnormally high blood pressure if the weights are gripped tightly. Vigorously swinging the arms without weight is safer, and the difference in caloric expenditure and fitness development between the two will not be significant.
Many walkers have tried ankle weights as a means of increasing the intensity of walking. These devices are not recommended, though, because they may produce injuries, primarily by distorting the walker’s natural gait.
