Take strength training. Most major gyms offer a line-up of resistance machines. Train your low back with torso rotation and extension machines. Choose one of many crunch machines for the abs. Use leg extension machines for the front thigh muscles and leg curl machines for the hamstrings. Hit the hip adductors and abductors with those inner and outer thigh machines that should be reserved for the obstetrician.
No wonder people are bored and don't have time for strength training.
And then there are lunges. The hip and quadricep (front thigh) muscles must generate force with most of the weight on one leg. Controlling momentum of the body (plus any additional loading like dumbbells) requires the abdominal and back muscles to stabilize the pelvis. The hip adductors (inner thigh muscles) and abductors (outer thigh/butt muscles) balance the leg so that you don’t tip over.
Lunges require no equipment and work all of these muscles functionally, rather than isolated along fixed lines of motion. Proper lunges help prevent problems and improve balance, walking, and running efficiency.
Why use five machines to train in a less efficient, less functional manner when better results can be had with just one exercise? Do you really think that a giant "seated bicep curl" machine that's been specifically engineered to match the leverage of the elbow offers your tiny biceps something that some heavy iron can't?
Lunges and rows and chin-ups and pretty much anything that involves simple you and gravity and a maybe a little iron are uncomfortable. And plain better.
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