After losing 40 pounds, becoming a bikini cover girl at age 48, and writing a bestselling book about drug use and the painful breakup of her marriage to Eddie Van Halen, Valerie Bertinelli has bared quite a bit in recent years. And when she joins Rachael in the studio she reveals even more; from how she avoided the sex talk with her son Wolfie to a "granny panties" vs. "floss up your bum" panty dilemma, nothing is off limits! "When panties are below the belly button, they can't be granny panties," Valerie protested when her boyfriend Tom gave her underwear a failing grade. Rachael agrees: "They're not granny panties because I'm not a grandma to nobody!"

Recently, Valerie's former One Day at a Time co-star Mackenzie Phillips shocked the world with revelations about the relationship with her father. "I've always known her to be this tortured soul," Valerie says about the friend she's known for 30 years. "She was always hurting herself; the drugs, the alcohol - she couldn't stay sober. Now, by hearing what we hear, we know why. It all totally makes sense to me now. She has made such a difference in so many people's lives because she's putting a face to incest, and incest survivors are coming out and they're feeling like they have a voice now."

"I know now," Valerie continues, "without a doubt in my mind, that she's going to stay sober because she's of service to people now. I'm proud of her."

Valerie's own struggle for years was her weight, and even after losing 40 pounds she admits that her journey is not over. "This whole maintenance thing is totally different than losing weight," she explains. "I've lost 40 pounds before, so now it's like 'Oh, I have to keep it off. This isn't as interesting and it's a little bit challenging in a different way.' Every day is different and it's about figuring out why I gained so much weight to begin with, and the chaos that was in my life and to get rid of that."

One of the tools Valerie uses to stay in shape is her trainer, Christopher Ross Lane, who demonstrates a few of the techniques he uses to help her stay looking fabulous. Watch the video above to see Rachael try a couple of these exercises.