Hotel room workout: twenty minutes that travel with you.

A hotel room workout pays off if it's short and done properly: twenty minutes of bodyweight exercise, five moves at forty seconds each, four rounds, on two metres of floor. What matters is that the last reps are hard, because muscle responds to effort.

Three nights in Manchester, breakfast with a client at eight, and a gym with one treadmill and two dumbbells. I see it often in the people I work with: the week away becomes a week off, and Monday means starting over.

What a week away asks of your body

• The flight. Hours without moving: shoulders, hips and ankles stiffen up.
• The chair. Taxi, meetings, dinner: you barely get up all day.
• Short nights. A strange bed, an early alarm, maybe a time difference.
• Your diary. Training has no slot, so it's the first to go.

Can you really train in a hotel room?

Yes, if the last reps are hard. In one comparison, a load of around 30 per cent of max, taken to the last possible rep, gave the muscle the same stimulus as 80 per cent. Stop well short of failure and you need at least 60 per cent. The mistake almost everyone makes in a hotel room: twenty quick, easy press-ups, and done.

Muscle has a memory. What you lose during a break comes back faster than it took to build: within six to eight weeks you usually regain most of it. One week away doesn't undo months of work.

A hotel room has nothing to pull on. You can push and train your legs anywhere; pulling without a bar is much harder. That's why a resistance band is the one bit of kit worth packing.

Upper and lower body, in turn. Switching from legs to arms keeps your heart rate up and blood moving round the body. In previously sedentary people, circuit training can raise strength by up to 30 per cent.

Which exercises can you do in a hotel room?

Five exercises, alternating legs, arms and core, forty seconds each, a few seconds to switch, four rounds. That's just over a quarter of an hour. First, three or four minutes of mobility: shoulders, knees to chest, ankles, marching on the spot.

The circuit. Squats, lowering as if to sit down. Press-ups, hands on the desk if the floor is too much. Reverse lunges. Forearm plank. Hollow hold: on your back, knees tucked, shoulders off the floor, stomach braced. Stop with one or two reps left in the tank. When it gets easy, lower more slowly or try a single-leg squat, holding the desk.

Only ten minutes? Set a ten-minute timer and do as many rounds as you can. Log the number: next trip, you have a score to beat.

Packed a band? Add a row: band under your feet, lean forward, elbows back towards your sides.

The day after a flight. Shoulders, hips and ankles first, then one easy round, well short of fatigue. Slept badly? A walk outside is enough: hard training, jet lag and a short night together are too much.

Mornings, if you can. After a workout, attention and reactions stay sharper for at least two hours. Just right for a ten o'clock meeting.

On Monday, you pick up where you left off.