I FEEL like the White Rabbit as I trot along the road constantly looking at my watch. I'm not late. I'm just trying to stop its constant beeping.

This is no ordinary watch. It doubles as a heartrate monitor. It can be programmed to beep when I'm not exercising fast enough, or if I'm going so fast as to threaten my health.

It's meant to help you work out at the optimum rate for your own body.

It certainly keeps me on the move. No stopping to admire a garden, adjust my gloves or feed the ducks. I'm discovering just how fast power walking needs to be if it's to give good aerobic exercise.

That beep acts like a grizzly baby who wakes as soon as you stop pushing the buggy, or a demanding Furby. No slacking.

A heartrate monitor is not only ideal for walkers and cyclists.

It comes into its own in the home gym, the big story in the fitness world, with people installing all kinds of equipment in the spare room. Is it a fad, soon to go the way of all those old-style exercise bikes now stuck unused at the back of the garage?

David Judd thinks not. The time has come to look again at the home gym, he says. At the moment seven per cent of us exercise in the home.

But the trend is catching up with America where twice as many swap the armchair for exercise in the spare room.

David is currently burning calories at a fair rate of knots at John Lewis in High Wycombe, where he specialises in sports equipment. The store has enlarged its demonstration area into a kind of gym, with David on hand to tread the mill, cycle, lift weights or explain the marvels of computerised performance.

He says: "More and more people are wanting to get fit at home. Not everyone has the time to go regularly to the gym.

"And the cost of home equipment is soon covered in saved gym fees."

But how do we make sure the equipment doesn't get added to the Items for Sale cards in the newsagent's window?

The key is to have the equipment set up where it is always ready to use, David says.

It's also important to buy just the right kind of equipment that you will enjoy using.

"If you like it you will use it. If the saddle on your exercise bike is not comfortable, you won't use it.

"We've come a long way since simple exercise bikes and rowing machines. One of the most popular pieces of equipment now is the Elliptical Cross Trainer."

This gives low-impact exercise because the foot boards rise with the foot as you walk, while arm bars give an action like cross-country skiing. It's good, safe exercise with the benefits of walking, skiing, climbing and running.

David adds: "One man I spoke to loved running but was told by his doctor to stop because of damaged knees. He chose this machine."

The Reebok Elliptical Cross Trainer, £399, comes with electronic resistance, programmable workout display and grip pulse heartrate sensor.

If it's body building you want, there are home gym systems that do the trick.

The advantages of a home gym are pretty obvious, including not needing to dress up in fancy gear, and having a shower handy.

As David showed me the various options I was fast running out of reasons why I couldn't possibly have a home gym. Being a homely soul, I worry that a big piece of equipment would be awkward to clean round.

"No problem," David assured me. "They all come with wheels so you can easily move them."

How about safety? Wouldn't I need a personal trainer to make sure I didn't cheat by going too slow? And how about people who might go at it too hard and damage themselves?

It's important, he says, that anyone with medical problems or who is elderly checks it out with their doctor.

And the heartrate monitor worn like a watch is a useful way to check you're not overdoing your exercise.

Another problem: boredom. How on earth do you stay motivated on your own at home?

If you can get another member of the family to exercise with you, says David, that's a great help. Perhaps a rowing machine for him and a treadmill for her.

Space? Think creatively.

The spare room, a conservatory, oust the car from the garage, use a corner of the bedroom some equipment doesn't use much floor area.

Keep motivated through setting targets of improved fitness.

This is where the hi-tech machines come into their own.

Top of the range exercise bikes have motivational computers which take you through a route, with increasing resistance as you go uphill.

Just like having a personal trainer next to you.