• Swing your arms. One good option: bend them at 90° and pump from the shoulder, like race walkers do. Swing them naturally, as if you're reaching for your wallet in your back pocket. On the swing forward, your wrist should be near the centre of your chest. Move your arms in opposition to your legs—swing your right arm forward as you step forward with your left leg. Keep your wrists straight, your hands unclenched, and elbows close to your sides. The vigorous arm pumping allows for a quicker pace, and provides a good workout for your upper body. And you'll burn 5 to 10% more calories.

• Add some interval training. For example, speed up for a minute or two every five minutes. Or alternate one fast kilometre with two slower kilometres.

• Choose varied terrains. Walking on grass or gravel burns more calories than walking on a track. And walking on soft sand increases caloric expenditure by almost 50%, if you can keep up the pace.

• Walk up and down hills to build strength and stamina and burn more calories. Combine hill walking with your regular flat-terrain walking as a form of interval training. When walking uphill, lean forward slightly—it's easier on your leg muscles. Walking downhill can be harder on your body, especially the knees, than walking uphill, and may cause muscle soreness, so slow your pace, keep your knees slightly bent, and take shorter steps.

• Try a walking stick or poles. A walking stick is helpful for balance, especially for older people. To enhance your upper-body workout, use lightweight, rubber-tipped trekking poles, sold in many sporting-goods stores. This is like cross-country skiing without the skis. When you step forward with the left foot, the right arm with the pole comes forward and is planted on the ground, about even with the heel of the left foot. This works the muscles of your chest and arms as well as some abdominals, while reducing the stress on your knees. Find the right size poles by testing them in the store: you should be able to grip the pole and keep your forearm about level as you walk. Many poles are now adjustable.

• Use hand weights, but carefully. Hand weights can boost your caloric expenditure, but they may alter your arm swing and thus lead to muscle soreness or even injury. They're generally not recommended for people with high blood pressure or heart disease. If you want to use them, start with one-pound weights and increase the weight gradually. The weights shouldn't add up to more than 10% of your body weight. Ankle weights are not recommended, as they increase the chance of injury.

• Try backward walking for a change of pace. It is demanding, since it's a novel activity for most people. Even a slow pace (3.2 kilometers per hour) provides fairly intense training. "Retro" walking is also a good option if you're trying to vary your workout on a treadmill or stair-climbing machine. And if you're recovering from a knee injury, it may help. Be careful when going back-wards outdoors: choose a smooth surface and keep far away from traffic, trees, potholes, and other exercisers. A deserted track is ideal. If possible, work out with a spotter, a forward-walking partner who can keep you from bumping into something and help pace you. To avoid muscle soreness, start slowly: don't try to walk backward more than a quarter mile the first week. Elderly exercisers or anyone else with balance problems should not retro walk.

• Choose the right shoes. Avoid stiff-soled shoes that don't bend. "Walking shoes" have flexible soles and stiff heel counters to prevent side-to-side motion. But for normal terrain, any comfortable, cushioned, lightweight, low-heeled shoes will do.