Yesterday afternoon, I spent an hour following the commands of a woman at least 30 years younger than me, as she directed me from a sweat-producing two-minute sprint on a stationary bike to 50 reps of standing glute kicks on each leg and then back to the bike. This went on and on, with 50 reps of a variety of other grueling exercises alternating with that bike. By the end of it, I was exhausted. And thrilled. I felt strong, alive, and hopeful.

My metabolism had also slowed down even further, and I was getting softer and softer.

When I decided to hire a personal strength trainer a couple of months ago, it was almost on a whim but, at 72, I’d been worrying about the state of my fitness. Nearly six years ago, I first wrote in NextTribe about being in the best shape of my life. I’d gotten lazy in my 50s and knew that I had to rein it in quickly, or I’d be sorry. I got back to a regular running routine and started going to the gym for strength training. I lost a few pounds and I felt great. I was even patting myself on the back for getting it together before it was too late.

By the time I reached 70, I didn’t feel all that bad, but exercise had slipped off the top of my to-do list. My metabolism had also slowed down even further, and I was getting softer and softer. Looking at myself in the mirror, my concern wasn’t with how I looked as much as it was with what I knew—that I needed to stay ahead of what was happening in my body or my life as I knew it would change radically.

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Should I Use a Personal Trainer?

I was a longtime runner, so I figured I’d push myself to start running further than I had for a while. It’s what worked in my 60s, so I was sure it would do the trick again. But I didn’t feel all that motivated, rarely running as far as I said I was going to. I’d work at it for a bit and then take a couple of days off.  I was literally losing ground. I kept thinking back on how much easier it seemed less than a decade ago to get back into shape. I even re-read that NextTribe piece to see if I could find inspiration there. Again, lots of starting and stopping—some running, some weight training at the gym, but mostly feeling discouraged.

Honestly, I could barely breathe by the end of the hour, but I knew I was onto something good.

On one of those trips to the gym, though, I ran into a friend of a friend who works as a trainer. I’m not sure what made me ask her if she was taking new clients, but I did and she was. My first appointment was a week later and, honestly, I could barely breathe by the end of the hour. But I knew I was onto something good. I’ve been going twice a week for two months now and I truly have never felt better.

I actually haven’t lost much weight, but I’m not sure that matters. Even writing those words surprises me because weight loss has always been my goal and my gauge for fitness. Still, I just made up how much I should weigh based on very old and very generalized information. I also knew that in order to weigh that amount I needed to eat fewer calories, and I knew that running four or five miles several days a week had helped me do that. But I honestly have no idea if any of what I did was very good for my overall fitness. Even at the gym, I’d just do a series of exercises I’d found online and I had no idea when to increase weights or reps, or even how to combine exercises to get the most bang for my buck.

Benefits of a Personal Trainer

Going to a trainer has changed all of that, primarily because she knows what she’s doing. She has studied kinesiology and is a certified as a trainer, and of course she is in amazing shape herself. And, even though she is more than 30 years younger than me, she works with people of all ages. Her oldest client is in her 80s. In addition to the twice-weekly workouts with her, she has helped me figure out better ways to eat for my body, has created a gym workout I can do on days I’m not with her, has helped me rethink how I approach running, and has convinced me of the value of walking a few days a week.

She watched me walk a few steps, could see the imbalance immediately and has added exercises to help loosen and straighten that area.

All of that just helps to remind me that, no matter how strenuous the workout, she is paying attention to what I can do and that she knows when to push and when not to. Even in one of our first couple of sessions, she asked me if I had any injuries. I said no, but that my upper back occasionally gets achy from sitting at a computer. She watched me walk a few steps, could see the imbalance immediately and has added exercises to help loosen and straighten that area.

Every time I go to her I leave knowing that having an informed trainer is so much better for me than trying to get in shape on my own. Each week she reviews her notes and creates two workouts for me and for each of her other clients. The exercises are based on my progression and on what I need to move forward. I would have no idea how to do that on my own.

I’m surprised in a way that it took me so long to decide to hire a trainer, but I truly felt like I knew what I was doing. I’d always been focused on weighing less and I knew that running more and eating less for a bit would help me accomplish that goal. But beyond feeling frustrated by it, I wasn’t paying any attention to how my body had changed and what I really needed in order to remain strong and fit for as long as possible. I’m not sure I would have ever said that the answer could be found in holding a plank as long as possible, but when I feel my core strength growing, I realize how wrong I was.

Read More: I Made Up My Own Crazy Diet and Lost 20 Pounds