Even decades after its introduction on the market, the “Thigh Master” remains a popular piece of gadgetry, with its claim that it slims and tones the thighs.
One reason women fell for this was because the original pitch-person for this device was 1970’s TV star Suzanne Somers.
“I did aerobics ‘til I dropped,” Somers says in the original TV commercials.
Then she discovered the Thigh Master, she says in the ads, and is shown using the device and praising its results.
To use the Thigh Master (and subsequent similar copycat products), one lies on the floor or sits on the edge of a bed or chair and places the device between the thighs — as shown below.
One then squeezes the thighs towards each other, against the resistance of the device.
In other words, these gadgets are portable hip adduction tools.
Hip adduction is the joint action of bringing the hips towards the midline of the body. This engages the inner thigh muscles.
The Thigh Master (and copycats) works only the inner thigh (hip adductor) muscles, yet the claim is that this gadget trims and tones the entire upper leg.
There are reasons why the Thigh Master won’t trim your thighs.
Only the hip adductor muscles are worked; it’s an isolation exercise of very small muscles.
This is the worst recipe for optimal fat burning.
Working just one muscle group, and relatively weak muscles at that, won’t cause a fat-burning cascade throughout the body—which is the only way to slash fat in the thighs.
In order to promote major fat burning, you must work large muscle groups by doing compound movements. Below are examples.
This dramatically increases the body’s energy needs when one uses moderately heavy to heavy resistance, or intensity such as with high jumping.
When the body’s energy needs are dramatically increased, serious fat burning results—fat is pulled from fat cells throughout the body, including in the thighs—to feed exhausted muscle cells.
This process shrinks fat cells, which results in fat loss and a leaner appearance.
This incredible metabolic process doesn’t occur by just sitting in a chair and moving one’s legs in and out, even if the device is set at high tension.
The nature of the movement isn’t intense enough to burn significant fat. Hip adduction is not a power based motion.
The inner thigh muscles are not big power muscles, like the quadriceps, hamstrings and gluteus maximus muscles are. Movements that are not power based just don’t burn many calories.
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Why would working only one small portion of the legs result in trimming and toning the entire leg?
The inner thigh will get toned (while the layer of fat remains unchanged), but the quadriceps and hamstrings will not firm up.
The toning of the inner thighs by the Thigh Master does not mean that sufficient fat will be burned to convert heavy thighs into lean, buff thighs.
Do not believe the claim that this isolation exercise will tone and sculpt the entire upper leg.
This is impossible because, as mentioned, only one small muscle group gets worked with the Thigh Master: the hip adductors.
There are six of these muscles for each leg, but even all put together, they form a small, weak muscle group.
Think about the big power movements of the lower body: squatting, pressing, jumping and sprinting. There is minimal hip adduction action in these movements.
These movements are powered by the quadriceps, hamstrings and gluteus maximus—big, powerful muscles.
If one performs exercises that target these muscles, the body will be forced to burn large amounts of fat to subsidize recovery from these workouts.
So there they all are:
Reasons why the Thigh Master won’t trim or tone the main portions of the thighs.
To slash fat in the whole leg and sculpt or tone them, one must perform intense compound movements like squats, deadlifts, leg presses, weighted walking lunges, sprints, hill dashes and box jumping routines.
Lorra Garrick is a former personal trainer certified through the American Council on Exercise. At Bally Total Fitness she trained women and men of all ages for fat loss, muscle building, fitness and improved health.