Which Sex Is Stronger? It Depends On the Test

If the battle of the sexes was reduced to a tug-of-war with a line of 100 men on one side of the trench and 100 women on the other, the men would win.

Likewise, male Olympic gold medalists consistently outperform their female counterparts. Carl Lewis, the 1984 winner in the men’s 200-meter dash, outran Valerie Brisco-Hooks by a solid 2 seconds. Alessandro Andrei of Italy won the gold for the shot put with a distance of 69 feet, 9 inches, while Claudia Losch of West Germany scored with one of 67 feet, 2 inches. Across the board, the male Olympic competitors beat the women in tests of speed, endurance and power.

However, an answer to the age-old question of whether men in general are stronger than women calls for specific, objectively measurable definitions of strength. A basic definition of strength is the maximum force or tension generated by a muscle.

Because of the variables in composition of men’s and women’s bodies, arriving at a measurement to compare men and women is not an easy thing to do.

If you measure the amount of tension in relation to muscle cross-section--usually per square centimeter of muscle tissue--you will find that men and women have exactly the same strength per unit of muscle. Yet most men’s bodies have proportionately more muscle mass than women’s. (Women generally have more body fat and less muscle than men; the female body actually stores fat more efficiently. Women’s propensity to store extra fat may have evolved from the need for energy reserves for pregnancy and breast feeding.)

In absolute terms of total force exerted--as in the tug-of-war example--men are stronger than women. Studies indicate that among a group of men and women, each weighing 140 pounds (to even the odds somewhat), the women’s upper-body strength will be about half of what the men’s is. Women’s lower-body strength is about 30% less.

But such findings hardly tell the story. If you account for men’s and women’s differences in size and body composition, you will find that the strength differences decrease noticeably. When you measure strength relative to lean body weight--essentially, muscle and bone mass--the differences in strength between men and women actually is slight. Studies in which strength was calculated per kilogram of lean body weight seem to show that women are a bit weaker in their upper bodies but that their leg-press strength is actually greater.

Ultimately, then, male and female bodies in the same condition with similar proportions of muscle to body fat will exhibit similar strength levels.

Physiologists measure muscle strength by methods that, basically, fall into two broad categories: static, or isometric, measurement, in which the muscle is tested as it contracts against an immovable force; and dynamic measurement, in which the muscle works against a moving resistance.

The tried-and-true way to measure one’s dynamic strength is by the one-repetition maximum (1-RM) method. It is fairly accurate and uncomplicated and can be done using either free weights or resistance machines. Simply put, you would lift the heaviest weight you can one time as you maintain the proper form. In practice, though, the measure is more likely to be arrived at through trial and error. That is, you would try lifting 100 pounds, find it too easy, rest a few minutes, then try 120 pounds.

With modern technology, however, strength testing has entered the computer age. Computer-assisted electromechanical and iso-kinetic methods can rapidly assign numbers to muscular forces generated during a variety of movements. These instruments measure the force, acceleration and speed a body segment exerts. Some even provide graphs of the changing tension in a muscle as it performs a full range of motion. An isokinetic machine such as the Cybex tests muscle tension at various speeds of contraction. This method is especially valuable in testing an athlete recovering from an injury.