Reporter's notebook: My 24 hours locked inside a metabolic chamber

ABC News' Mara Schiavocampo shares her experience in isolation for 24 hours.

It was an offer I couldn’t refuse: The opportunity to spend 24 hours locked inside a metabolic chamber. Yes, I was actually excited about this.

So when "Good Morning America" approached me about doing this story, it was a no-brainer. The chamber, at New York’s Mount Sinai St. Luke’s Hospital, measures oxygen consumption and carbon dioxide production to determine exactly how many calories you’re burning the entire time you’re inside. That includes while you’re sleeping, exercising or just hanging out. It can even tell if you’re burning carbohydrates or fat so that you can figure out the ideal fat-burning workout for your body. Pretty cool, huh?

Not so cool? Spending 24 hours inside the equivalent of a hospital prison cell. The 9-by-11-foot room is vacuum-sealed, which means once the doors shut, you’re in until the test is done. No human contact, period. Inside, there's a small desk, a futon, a mini fridge, a sink, a treadmill and, of course, a toilet. And keep in mind, it’s a hospital, so they're not exactly luxury accommodations. They suggested I bring my own sheets and blankets. I didn’t. I wish I had.

Periodically my producer or someone from the hospital came around to check on me. Even though they were inches away, we had to talk on the phone because we couldn't hear each other through the glass. Every five hours, they could pass me things I needed through a vacuum-sealed window. I was immediately lonely. And bored. I’d expected to enjoy the free time much more.

As it turned out, there wasn't much free time at all! I had a lot of work to do. I had to complete three different workouts so we could measure their effect on my body: yoga, a long run, and a high-intensity interval workout. As luck would have it, I didn't feel like working out that day, of all days. But that’s why I was there, so I dragged myself up and got it done.

I’d brought a bunch of books thinking this would be a mini getaway. It wasn't, and it wasn't exactly fun, but it was really cool. Best of all, it will teach me a lot about how my body works, a gift that’ll last a lot longer than 24 hours.