While a canny nutritional programme, plenty of rest, and adequate recovery between workouts are all important for preserving fitness as you get older, certain key workouts are also necessary to keep you as fit as possible. For example, if you have yet to reach your 45th birthday, you will want to expand your aerobic capacity (V02max) as much as possible, so that any fall-offs which occur after the age of 45 will be like mere pebbles dropping from Mt. Everest.

One of the best workouts you can possibly carry out is the great '4-954' workout, in which you complete 4-minute work intervals at an intensity high enough to make your heart rate reach 95 per cent of maximal at the end of the interval, with 4-minute recoveries. Also good for you are cycling, swimming, or running races which last from 12-20 minutes.

From 45 to 60
If you're between the ages of 45 and 60, your motivation may fall a bit, and physiological problems include a modest loss of aerobic capacity (V02max) and a small decline in muscle tissue (muscle atrophy). Also, age-related increases in muscle soreness and tissue stiffness increase the need for longer recoveries between workouts, forcing a cutback in training volume. One solution is to conduct some 'Sparks Sessions' (described in the first article). To increase motivation, make your high-intensity sessions more fun. A great motivational workout involves going to your favourite place in the city or countryside, letting your everyday cares and concerns drop away, and feeling the power in your legs by occasionally bursting at race pace for 20 to 30 seconds at a time as you run or cycle.

Strengthen your leg muscles by doing more hill training, and minimise soreness by adding at least one extra rest day for each two weeks of training and by cross-training occasionally (run in the deep end of a swimming pool or use an exercise cycle if you're a runner). Prevent leg-muscle atrophy, which can account for about 20 percent of age-related declines in fitness, by getting serious about weight training.

For the over-60s
If you're over 60, your V02max will attempt to plummet, and your muscles and connective tissues will lose some strength. In addition, body-fat levels will try to climb, in concert with some muscle atrophy. Your response should be to add 'Senior Intervals' to preserve your V02max and to compensate for losses in aerobic capacity by boosting your lactate threshold. Trim body fat by relying on long, weekend walk-run combinations which last for a couple of hours. Continue weight training to thwart muscle shrinking. To enhance recovery, rest at least five days out of every two-week period.

To do the 'Senior Intervals' (also called the '210-3' Workout), run, cycle, or swim for two-minute intervals at the best intensity you could sustain in a 10-minute race, with three-minute recoveries. For a lactate-threshold booster, warm up, and then exercise for 10 continuous minutes at a pace which keeps heart rate in the 85-88 per cent-of-maximal range. Recover for five to six minutes, and then repeat this 10-minute surge.

Owen Anderson