File these under: Facts you wish you had known when asking for a puppy as a kid.

1. Pets relax your body and mind. One study showed that spending just 12 minutes with an animal lowered blood pressure, anxiety and the release of stress hormones among hospital patients.

2. Adopting a pet is good for your heart -- and not just in a warm, fuzzy way. Researchers say those who spend time with dogs have lower cholesterol.

3. You can skip the gym. Studies have found that dog owners are less likely to be obese than those without pets.

Want all these benefits without the related stress of paying vet bills? Volunteer at an animal shelter. Most organizations just require a one-day orientation, and then you can set your own hours. Your health will go to the dogs -- in a good way.

A recent study shows that spending money on other people leaves the spender feeling happier than spending it on him or herself. As little as five dollars spent on someone else boosted the mood of study participants by the end of the day. That means that donating your money to a worthy cause instead of that daily latte will have you feeling buzzier than any amount of caffeine.

Campaigns like Paul Mitchell's #GivingIsMyStyle are rewarding without being financially demanding. All you have to do is post a tweet or Instagram @PaulMitchellUS with the hashtag #GivingIsMyStyle, and say why you think it's important to give back or how you're making a difference in the world. In return, you earn a spot in their new Web site's "giving gallery," and they donate $1 (per person, up to $200,000) to one of the many charities they support, including Reforest'action, Boys & Girls Club, Waterkeeper Alliance, Grow Appalachia and Bright Pink. That could go a long way toward planting trees, creating brighter futures, improving water quality, developing communities and lowering the risk of breast cancer.

Creating an Instagram or Twitter account is 100 percent free, so you get all the benefits of donating money without spending a dime. Learn more at PaulMitchell.com.

Fact: Natural light elevates people's mood. Another fact: Those who exercise report feeling calmer, more energized and less stressed. Add these two findings together, and you have what researchers are calling "green exercise." A study at the University of Essex finds that those who are active outdoors notice improved mood and self-esteem within five minutes of being outside. Add a feel-good element like cleaning up your community into the mix, and you basically have a recipe for giddiness.

Volunteer efforts like beach, river or lake clean-ups combine all three elements -- plus, researchers found that being near a body of water enhances the mood-boosting properties of green exercise.

Anyone who's ever gotten sucked into an episode of "Hoarders" knows that clutter can take a psychological toll. According to a study by Princeton University, those shoes with tags still attached, your childhood collection of Beanie Babies and the clunky kitchen appliances you'll put to use "one day" are actually making it harder for your brain to focus and process information.

Clear your space (and your mind) by giving things to a local shelter or donation center. You increase your productivity and also gain a nice chunk of change in tax write-offs. Plus, recycling old things keeps them out of landfills, lowers the amount of resources needed to produce new products and creates jobs in your community. (Note: Watching "Hoarders" while de-cluttering is seriously motivating.)

All friends have benefits -- health benefits, that is. Researchers at Brigham Young University found that people with social connections have a 50 percent higher chance of survival than their isolated counterparts. The study found that being socially isolated is as bad for your health as smoking 15 cigarettes a day. Time to phone a friend!

To increase your social activity, volunteer your time to a bustling center of activity, like a hospital. Volunteers at hospitals can expect to partake in tasks like manning the gift shop (selling bubble gum cigars to new dads isn't a bad gig) or acting as a translator between hospital staff and patients who speak other languages.