When it comes to money, superstar tennis championSerena Williamsreveals she likes to spend smart.

“I don’t spend money — when I do it’s on my daughter. I usually invest my funds. I am the most boring spending ever,” Williams, 37, tells PEOPLE. “Don’t spend it, invest it,” she advises.

The tennis star even admits that she’s bad at spending her hard-earned cash on herself.

“I am really bad at treating myself, so I am learning how to treat myself more. I am working on it. I’ve thought about some jewelry,” she says.

Serena_Oct2019_0558B_flat

“Obviously the Wilson tennis balls are super important to me,” she says of the popular tennis ball brand — just one of the many tennis-themed items shoppers can purchase through the storefront.

“The resistance bands I also use as stretch bands and they are very essential,” she says of theAmazonBasics Pound Resistance Pull Up Bands, before explaining her travel training sessions.

“We travel with everything in a massive big training bag and we normally just throw a ball in there — I also like my beats headphones which I normally walk onto the court with,” she explains.

“I have a playlist that I always listen to … I try to listen to more motivational music and normally listen to more lyrics as opposed to just beats,” Williams says of her pre-match pump-up.

In addition to workout and sports-related items, such as theSchwinn Indoor Cycling Bikeand theAmazonBasics Extra Thick Exercise Mat, the athlete’s storefront also consists of some of her favorite mommy items for her daughter, Olympia.

Serena Williams.Matthew Stockman/Getty

Serena Williams, Maria Sharapova

Serena_Oct2019_0211B_flat

“Basically, everything from grabbing pampers on our storefront, or different medicines if she gets sick,” Williams says referring to her 2-year-old daughter, who she shares withhusband Alexis Ohanian. “One thing I really like isOlly’s, these little gummies for kids. It’s also a company I invested in. I grab them on the go. When it comes to Olympia, she basically has her own account on Amazon,” she jokes.

Williams’ storefront also features some relaxing downtime items such as theTriggerPoint Impact Handheld Percussion 4-Speed Massage Gunand theProsourceFit Acupressure Mat and PillowSet for Back/Neck Pain Relief and Muscle Relaxation.

And in the midst of the holiday season, most people will be doing more relaxing (and eating) than exercising. But the mother, tennis champion and fashion designer encourages everyone to get up and out in order to feel good and balance out all those holiday meals.

Serena Williams Amazon.

Serena Williams Amazon

“I say a half-hour out of your day to go for a walk or a run — it’s really not a lot of time out of your day,” she suggests. “Especially if you are eating a lot during the holidays — and sometimes I think about that during my off days, just go out for 20 minutes on a run, at least three days a week and it makes you feel better.”

Serena Williams Instagram

Serena Williams Instagram

“I am hands-on in everything I do, and this is no exception,” she said at the time.

“I basically don’t balance,” she said, laughing. “When I do something one day, it is 100 percent. Then when I am done, I am done and on to the next thing! I live and breathe fashion in the tennis off-season, but no matter what else I do, I am always a mom and I love every minute of it.”

Shop Williams’storefront here.

source: people.com