The contestants on The Biggest Loser work hard. They spend the majority of their day in the gym working with very talented personal trainers. For a brief period their life is focused around losing weight. We all know that just isn’t how it works in the real world though.
Even if we could have access to such a phenomenal gym and experienced trainers, sometimes exercise machines just do not translate well into real world fitness. And honestly, you do not need machines to complete an effective workout. The Biggest Loser actually proved that in season 11 when they brought in two new trainers who had more experience with mixed martial arts, CrossFit, and boxing than they did with fancy treadmills and cable equipment. The teams who worked in the non-traditional, no machines setting actually seemed to have better weight loss and strength results than those who stuck with treadmills and machines.
There are several reasons machines don’t translate well into real world fitness. First, they are designed to isolate muscle groups rather than work the body as a unit.  This can lead to muscle imbalances and potential injuries if agonist and antagonist muscle groups are worked evenly.
Second, exercise machines rarely allow you to move at a speed that motions occur in the real world.  Upper slow movements have low carryover to activities of daily living.
Third, exercise machines typically lock you into one movement plane. For example, leg extensions allow you to lift your leg at the knee up and down. That may be fine as part of a rehab program, but for real world fitness you’d perform walking lunges with trunk rotation side to side.  This would give you a more dynamic multi-plane movement.
Other limitations of exercise machines are:
Complete home gyms can cost several hundred to a few thousand dollars. The alternatives to home exercise equipment are much less expensive.
Exercise machines take up a lot of space. This is especially important factor to consider if you live in a small place. Even models that slide under the bed need to be slid out and set up somewhere. While we can all dream, not everyone’s “real world” includes an extra room in their house dedicated to fitness equipment.
Exercise machines don’t travel well. You can’t just pop your Buff Body 3000 into your suitcase and head out on a business trip. Real world fitness needs to work for you, not against you. Since you can’t take your machine with you, you might not work out. There’s no reason to make travel harder than it has to be. Creating and keeping fitness routine that can go on the road with you will make it more likely you actually follow through on it when you are out of town. Many people who travel regularly prefer to use bands and sneakers to get their workouts in. Even the hand weights get left at home in these days of overweight luggage fees. Exercise bands are extremely light weight, come in several different levels of resistance, and can even be tucked into your sneakers to save space in your luggage.
Finally, if you are short on time, exercise machines won’t help you get through your workout as quickly as other types of fitness equipment. You will need to stop between each exercise to reconfigure your machine. These pauses in your workout every 1-2 minutes really kill the effectiveness of your workout. The ideal workout keeps going and never lets you bring your heart rate below your personal baseline. You just can’t accomplish this with an exercise machine.
If you want an effective workout that is easy to duplicate whether you are home or traveling, then ditch the machines and look for fitness tools that actually work in real world fitness.