Running with a weight vest can improve your speed

By Owen Anderson, Ph.D.

A famed Finnish exercise scientist recently reported some fascinating new research results for runners, part good news, part merely strange. The good news is that you can boost your leg-muscle power and speed in just four weeks. The strange news is that no special workouts are needed. In fact, what you wear when you run is far more important than how you actually train.

This doesn't mean you need to slip into polypro pants, a paisley singlet or energy-return shoes, however. According to the new research, simply wearing a weighted vest will do the trick. If this sounds a little offbeat to you, perhaps it's because you're no rocket scientist. Those who are, the NASA experts, have long realized that weightless space travel weakens leg muscles, while jumping around on Jupiter (the planet with the most gravity) would build leg power.

Finnish Researcher Helkki Rusko didn't have a large enough budget for interplanetary travel, so he opted to test the gravity-leg-strength connection by strapping weighted vests onto his subjects, 12 well-trained athletes. Each vest weighed 10 percent of the subject's total body weight, forcing leg muscles to work harder, even during routine activities like standing and walking. Rusko's subjects wore their vests all day long for four weeks and during at least three of their eight weekly workouts.

The initial results were negative. After four weeks: the runners needed more oxygen to run at a given pace (that is, their running economy had deteriorated). Similarly, their leg muscles were producing more lactic acid, a possible sign of muscle fatigue.

Fortunately, Rusko didn't give up at this point. For the next two weeks, he asked his subjects to take off their vests and continue training as usual. A retest at the end of this two-week period produced far different results.

This time, lactate threshold was 2 percent higher (meaning that the runners produced less lactic acid), and max V02 had also increased by 2 percent. Two other important measures also improved: Endurance while sprinting soared by 25 percent, and stair running speed, a good indicator of leg-muscle power, increased by 3 percent.

These improvements in speed and power occurred because weighted-vest running altered the test subjects' basic running mechanics and activated the fast-twitch muscle fibers in their legs. Only the group's running economy remained slightly depressed.

The bottom line? Wearing a weighted vest has the potential to strengthen your leg muscles, make you faster, improve your kick and make you a better hill runner. However, it's important to bear in mind the following points:

* If you decide to try using a vest, wear it as much as possible during your daily routine. Wearing a vest only for workouts may not provide enough stimulation of fast-twitch muscle fibers.

* Wear the weighted vest during some, but not all, of your training sessions. The vest actually slows your average speed during training, so constant use would eventually teach your muscles to work at a slower rate.

* You'll have to stop wearing the vest for several weeks before you see positive effects. Your body needs a "furlough" to recover from the extra stresses of vest wearing.

* Don't try to substitute hand weights for a vest. Hand weights may slightly increase your oxygen consumption, but they won't do anything for your leg muscles or increase your max V02 to any significant degree.

* Don't attach weights to your ankles. The extra poundage could cause injuries and may wreck your running economy.

* Weighted vests will probably prove most beneficial to middle and short distance runners. Distance runners may be able to improve their lactate threshold, max V02 and kicking ability by using a vest, but they must guard against loss of running economy. You can buy weighted vests in some sporting goods stores.

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