Here’s how you can give it a go:
Start by adding intervals of power walking – as fast as you can walk – or jogging for up to 30 seconds. Do this at least six times during a 30-minute walk. Then, when you get comfortable with interval training, intensify your workout so you’re doing 10-12 speedy intervals over 30 minutes, about one interval every 2.5-3 minutes. You can time these fast intervals using the stopwatch on your mobile phone, or the second hand on your watch.
Combine 10-20 laps of swimming with other water exercises:
Kicking only Using a kickboard for balance, add a lap of fast kicking then swim 3-5 laps of regular swimming.
Arms only For 3-5 laps of every 10-20 laps, use your arms to propel you down the pool, while holding a buoy between your legs to keep you afloat.
Sprints Add a half- or a full-lap sprint of a stroke, for 3-5 laps of every 10-20 laps that you swim.
Alternate strokes Add a sprint lap of one stroke, and then perform 3-5 laps of another stroke.
Flat road Add in 6-8 of your fastest sprints for 30-60 seconds in a 30-minute workout.
Gentle hills Include 3-6 gentle hills that allow for a seated climb during the course of a 30-minute workout.
Big hills Add in 2-4 big hills for a standing climb in your 30-minute workout. When doing a combination of hills and flat roads, use distant landmarks, like houses, to give you something to aim towards during intervals of speed.
Circuit training is basically interval training, but with resistance exercises and cardio in the same session. This means you can complete a set of weights in a chair, then do 1-2 minutes of cycling, jogging or marching on the spot. For added intensity, do a different cardio and resistance exercise at each station. Or you can add in intervals of cardio in between doing sets of resistance – such as periods of marching on the spot in between doing sets of hand weights.