Barack and Michelle Obama's relationship was put to the test during his eight years in the White House.

As the former President shared in his recently released memoir, his eight years in office were especially tough on the former First Lady, noting how he sensed an "undercurrent of tension in her, subtle but constant" and a "loneliness" so worrisome that it kept him up at night.

"There were nights when, lying next to Michelle in the dark, I’d think about those days when everything between us felt lighter, when her smile was more constant and our love less encumbered," he wrote, "and my heart would suddenly tighten at the thought that those days might not return."

While the Obama's marital struggles were previously hidden, he told People in a new hour-long interview that it "was the truth of our time in the White House." He added, "Michelle very much believed in the work I did but was less optimistic about what I could get done. [...] She's more skeptical about politics and more mindful of the sacrifices to the family."

Nonetheless, "I think we came out of it whole," he told the outlet. "There were great joys in the White House. There was never a time where we didn't recognize what an extraordinary privilege it was to be there. Most importantly, our children emerged intact and they are wonderful, kind, thoughtful, creative — and not entitled — young women. So that's a big sigh of relief."

He went on to briefly share some of the cause of Michelle's stress, saying “during the time we were there, Michelle felt this underlying tension. The pressure, stress, of needing to get everything right, to be 'on' at every moment."

"We did," he admitted. "It was like a big exhale right after we left office." Obama continued, "It took some time to talk about how she had felt. Once [the presidency] was done, there was possibility of her opening up ... but more importantly just her being able to let out a breath and relax."

Michelle "has been more relaxed and more joyful since we left office," he shared. "That allowed us to just enjoy the deep love that comes with a marriage this long. But also to be friends again."

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