For some people, its hard to believe that the oldest millennials are fully approaching midlife. Individuals in this generation encompass those born between 1981 and 1996, according to the Pew Research Center , making the oldest millennials 43 and the youngest 27.

Its easy for those in this age range to feel like they have their whole lives ahead of them (because they do!), but the practices they do now are actually what set them up for health success as they get older.

What can millennials do now to age well? There is probably no one better to answer that question than millennial doctors. Below, physicians from different parts of the country and medical fields share their rules for staying healthy now and as they age. (And honestly, its probably advice all of us should be following not just millennials.)

Get regular physical activity.

For me, physical exercise drives everything, said Dr. Kenneth Koncilja , a geriatrician at the Cleveland Clinic. When Im more active, I eat healthier, I drink less alcohol, I sleep better. So for me, that is my foundation.

Koncilja said he prioritizes time in the gym, particularly in fitness centers that have some sort of childcare or activities for his kids.

Dr. Rene Rodriguez Paro , a pediatric cardiologist in California, said she fell out of her exercise routine for a while and started to feel less happy and more burned out as a result. About 10 years ago, she slowly got back into her exercise habit.

Just a little bit of exercise a day ... it really just changed everything, and it sounds ridiculous, but it did make me feel better, Paro said.

I have a consistent exercise routine that I do six days a week and give myself one day of rest. Ive run 13 marathons ... I also strength train, because I definitely know the huge importance of muscle mass and ... having mobility in the long term, she continued. I use the Peloton bike as cross training, have done some swimming, have done a triathlon, but my main exercise routine is running.

Dr. Joshua Levenson , a cardio-oncologist and director of the Center for Cardio-Oncology at the University of Pittsburgh Medical Center, emphasized the importance of maintaining muscle mass.

For those who already feel healthy, strength training for women especially is definitely one of the modifiable factors that readers can and should focus on now, Levenson said. We start to lose muscle mass over the age of 35, so keeping strength up now will pay off decades down the line.

Lean into a plant-forward diet.

Most recently, Ive been trying to be better about doing things that we were taught as kids, like eat more vegetables, eat more fruits, so now Ive been doing a lot of plant-based eating as much as possible, said Dr. Kelly Cheung , a resident physician in Los Angeles.

Although practicing a plant-based diet is definitely challenging because theres a lot of meat ... in our culture, Cheung noted that research shows the diet can lower your risk of cancer.

Paro said she also focuses on a plant-forward diet.

Im not a vegan or vegetarian. I eat various different proteins, but I really try to focus on trying to get at least one serving of fruits and vegetables in with every meal and snack time, she said.

Care for your mental health.

I think another thing is mental health . I think were more likely than prior generations of physicians to be open and willing to discuss therapy, Koncilja said. Seeing different therapists and mental health providers are helpful for me to be more resilient day to day in my career and to relate to my patients who deal with their own stressors, depression and anxiety.

All generations have pressure and cope with it in different ways, Koncilja added, but being open about mental health care and taking an active role in their own treatment is something he and his fellow millennial colleagues do.

Paro also shared that stress management is important for her.

I have a daily mindfulness practice where I have a gratitude journal. I do a three-to-five-minute meditation every morning and have been doing that daily for about nine years. That has had a very profound effect on dealing with the daily stresses of being a mom and a doctor and in a leadership position and wanting to be a good wife and family member, she said.

Dr. Janet Nwaukoni , a family physician based in Chicago, said that she also practices daily mindfulness and gratitude each morning. These exercises help you shape your day and create your narrative, which is essential to your overall health, Nwaukoni noted. Think about it: If you go into the day grateful for your family, friends and the sunshine, youll be less likely to dwell on the bad stuff, which can create stress and anxiety both of which are tied to high blood pressure and trouble with sleep .