I thought lifting weights was enough to keep me strong in my 40s until I discovered the benefits of this simple bodyweight exercise

What do you buy yourself for your 44th birthday? A new bag? Make-up? None of the above. For me, it was a brand-new box.

My old plyometric box got thrown out during some building work, so when I received the Mirafit Hybrid Plyo Box, I couldn't wait to start jumping and stepping.

No, it's not your usual birthday present, but since I've been reading about the benefits of jumping for stronger bones, I couldn't have been more excited. Here's why.

Why box jumps? 

I love a squat. Back squats, front squats, goblet squats; you name it, I’ve probably tried it. As a fitness expert and fitness journalist, I know how important strength training is, especially as we get older. But now that I’m comfortably in my 40s, I’m paying much more attention to my bones.

Women naturally begin to lose bone density as they age. And while lifting weights is one of the best things we can do to keep our bones strong, plyometrics have also come up trumps at stimulating bone formation.

That's partly thanks to osteoblasts, specialised cells responsible for building new bone tissue. Think jumping, hopping and other explosive movements. Or, in my case, box jumps.

My plan for the next phase of my training was to add a new springy element and swap my usual barbell squats for box jumps. And while I won't ditch my squats anytime soon, they made me realise my usual strength sessions might be missing something.

Why box jumps?

“The term ‘plyometrics’ might sound technical, but the concept is quite simple,” says Jessica Robinson, Level 3 Personal Trainer and ambassador for Mirafit. “Essentially, plyometric exercises involve explosive movements such as jumps, hops or burpees that train your muscles to produce maximum force in a short period of time.”

The bone benefits come from what happens when you land. “Each time you land from a jump or hop, the force travelling through your skeleton places a small but manageable amount of stress on the bones,” explains Robinson. “This then triggers bone-building cells, called osteoblasts, to strengthen and reinforce bone tissue.”

And that's particularly relevant to me now I'm in my 40s. While I'd always associated lifting weights with staying strong as I age, I'd given much less thought to maintaining power – essentially, how quickly your muscles can produce force.

Research suggests muscle power declines faster than strength as we age, which is another reason Robinson believes plyometric exercises are worth adding to your training.

Squats v box jumps

The first thing I noticed was just how different box jumps felt from my usual lower-body training. With a squat, I think about the weight on the bar, my depth, keeping everything controlled, my knee in line, and then driving back up.

With a box jump, there is no slow drive. You have to produce enough force to get yourself off the ground quickly without shinning the box (the worst) or falling flat on my face. My legs are strong, but I could tell right away I wasn't used to asking them to work like this.

My heart rate climbed pretty quickly too, and after a few sets I could feel my calves, quads and glutes working. So rather than chasing reps, I kept the sets short and focused on the explosiveness and height to get me safely on the box.

Robinson recommends around four to six reps per set if you're using box jumps specifically to develop power, with plenty of rest in between. This worked well for me. I could focus on each jump instead of getting tired and turning the exercise into cardio.

Do it right

I'll admit, once I got comfortable, my immediate instinct was to use the highest side of the box. Surely higher means harder and, therefore, better? Apparently not. “The effectiveness of a box jump isn't determined by how high the box is, but by the quality and intent of the movement,” says Robinson.

In fact, going too high can simply encourage you to pull your knees towards your chest to clear the box rather than actually producing more power. Instead, I used a box around knee height, and concentrated on jumping explosively and landing softly with my knees bent.

And this is where I noticed another benefit of box jumps: concentration. You need coordination, balance, and enough control to stick the landing. After a few sessions, the movement started to feel much more natural, and I was noticeably less hesitant about that initial jump.

Will I be swapping squats for box jumps permanently? Not so fast. I still want the strength benefits of squatting, and resistance training remains a big part of my weekly routine. But I've realised that I don't have to choose between strength and power.

Robinson recommends performing box jumps two to three times per week, depending on your overall training and recovery. If you're using them to develop power, she suggests doing them near the beginning of your workout while your muscles are fresh, then moving on to the rest of your session.

That's how I'll use them from now on: a few sets of good-quality jumps to start before I get into my usual weight routine. At 44, I'm not looking to make my training easier. I just want to make sure I'm training for what my body needs now, and what I want it to still be able to do in another 20 years.

And that means variety. I want to jump, lift and practise movements we don't necessarily do much anymore. I mean, think how much you used to jump as a kid and how natural it felt.

Nowadays, the aim is to be an all-rounder, with strong bones, strong muscles and good coordination. So while I'm certainly not ditching my squats, I’ll keep throwing in box jumps to keep things fresh and my body agile for as long as possible.