Strength Shoes: The Current Bottom Line!

Frederick C. Hatfield II, MS, MFS, CSCS

"Cranky scientists"? Scientists are indeed "cranky", but they are so out of necessity. When they conduct research they have many controls to try to control plausible rival hypotheses. Good idea on the surface, but it doesn't always work. Training is an integrated process that involves several factors. Many are often purposely eliminated in a research setting. In an athletic setting, a study on weight training and gains in mass and strength is going to be influenced by conditioning regimens, nutrition, supplementation and other external factors.

Another factor is the practice of looking at data without considering how it was collected. During the review process, methodology is scrutinized, so it shouldn't be a source of concern. In the case of the strength shoe research studies, however, some were poorly designed. I summarized a 1996 study (Porcari et al, 1996) as follows:

"In the recent study, 72 college-age men not previously involved in athletics or fitness training were randomly assigned to three groups of 24: a control group who did no training, a control group who trained in regular shoes, and a group who trained in Strength Shoes. The training groups trained three times a week for 10 weeks. They followed identical programs prescribed by the manufacturer. All subjects were pre- and post-tested for 40-yard sprint, vertical jump, standing broad jump, and right and left calf girth.

"There were two dropouts in the no-training group, eight in the regular-shoe group, and 10 in the Strength-Shoe group. Seven of the Strength-Shoe dropouts and one of the regular-shoe dropouts were due to injury that could be attributed to the training.

"The changes in performance and calf girth are summarized in the table. Both training groups showed a tendency to improve their sprinting and jumping by 0.5-1.6%. The Strength-Shoe group tended to do better than the regular-shoe group in the sprint and vertical jump, while the trend was reversed for the broad jump. There was also a tendency for the Strength-Shoe group to develop bigger calf muscles. None of the differences between any of the three groups was statistically significant, so we can't say whether any of the observed differences are likely to be true for athletes in general."

Later in my review, it was written:

"You should also check out an amusing, no-nonsense report of a less formal experiment with these shoes by seventh graders. It's part of CBC Television's award-winning Street Cents site. Their conclusion: borrow a book about training if you want the most cost-effective way to enhance your performance.

I have had considerable experience with athletes using the Strength Shoes. My impression up until now has been that these shoes might enhance performance of experienced athletes if they are used with the right kind of training program. But the research to date indicates that the right kind of training program might produce even better results with normal shoes. I cannot recommend Strength Shoes."

With the exception of the sentence, "I have had considerable experience with athletes using the Strength Shoes," none of these words are mine! The reviewer added the conclusions. At the time I knew nothing about an amusing, no-nonsense report. "My impression" still remains the same, which is that the strength shoe can indeed help enhance performance of experienced athletes when integrated with other training methods. Furthermore, I recommend Strength Shoes under the appropriate conditions.

Ads for the Strength Shoe have claimed that up to 0.2 seconds can be taken off the 40-yard time, nine inches can be added to the vertical jump, and calf girth can be increased by two inches. I don't believe these results can be guaranteed, but I do believe that proper use of the shoes can indeed yield results that warrant their use. The strength shoe is just a tool in your overall training. Used exclusively, it won't make you a great athlete. I can say the same thing for squats, sprints, agility drills or any other exercise. It is an integrated approach to training that brings about peak performance.