Running v aerobics

Running

How quickly will it make a difference? After two to three weeks if running three or more times a week.

How many calories does it burn? Around 612 per hour if you run six miles per hour (a 10-minute mile). You will burn more calories running off-road as your legs have to work harder on soft ground.

Will it keep me motivated? Treadmill running, hamster fashion, can be tedious: run outside, changing your route and terrain whenever you can. As you get fitter, challenge yourself more by entering fun runs.

Specific benefits: The basic running action strengthens the hamstring, quadriceps, iliopsoas muscles at the front of the hips, calf and the gluteus maximus muscles each time you take a stride forward. The pumping action of your arms will strengthen the upper body to some extent. And it's among the best forms of aerobic exercise.

Risk factors: Your feet absorb three to four times your body weight every time they strike the ground and a shock reverberates up through your legs and into your spine. Good shoes help to cushion the blow and reduce the risk of injury to the knees and other joints.

Aerobics

How quickly will it make a difference? After four to five weeks of twice-weekly classes.

How many calories does it burn? 374 per hour.

Will it keep me motivated? It depends on your instructor. Classes that stick to exactly the same format every week can become too predictable for both muscles and mind. As with all class-based workouts, there is little scope for progress, so there will come a time when you will want to try something different.

Specific benefits Aerobics classes incorporate an element of dance that will improve coordination and spatial awareness.

Risk factors Low-impact aerobics - at least one foot remains in contact with the floor at all times - are preferable to high-impact classes for anyone prone to back and joint problems.

Victor: running

Tennis v squash

Tennis

How quickly will it make a difference? After six to eight weeks of twice-weekly matches.

How many calories does it burn? 476 per hour in a singles match or 340 in a doubles.

Will it keep me motivated? Tennis is competitive and in the summer there is nothing better than heading outdoors to a tennis court. However, your motivation to play can be dampened somewhat when it comes to seeking out indoor courts over the winter months.

Specific benefits The power for a shot is initiated from ground level - the strength for a great serve is provided by the push off from the quadriceps in your thighs. Sharp turns and twists put the abdominals and upper body through a vigorous workout, holding the racket and hitting the ball exercises your arms and shoulders, and your forearms absorb the impact from the ball contact.

Risk factors It works one side of the body more than the other, so muscle imbalance is common unless you work on your less-dominant side in the gym.

Squash

How quickly will it make a difference? Two to three weeks if playing three times a week.

How many calories does it burn? 748 per hour.

Will it keep me motivated? Undoubtedly. It is sociable and, if you join a club, there will be coaching and a league structure.

Specific benefits Recently rated the number-one healthy sport - ahead of rowing - by Forbes magazine, squash is easier to learn than tennis and you can play all year round. It also helps to improve the strength of your legs, arms and core region.

Risk factors There is a sporty adage that goes: "You don't play squash to get fit, you get fit to play squash." Because it is so physically demanding, researchers at Liverpool John Moores University recently warned older and unfit people not to launch into it full-pelt as it could put unnecessary strain on the heart and body.

Victor: squash

Weights v circuits

Weights

How quickly will it make a difference? After the first session, your muscles will feel more toned, but noticeable changes will take three to four weeks.

How many calories does it burn? 136-340 per hour depending on weight lifted and the recovery time between repetitions and sets.

Will it keep me motivated? If improved body tone is your solitary goal, then yes. But otherwise it can become tedious.

Specific benefits Great for improving muscle tone and bone density. Combined with aerobic exercise, resistance and weight training has been shown to speed up the rate at which calories are burned, thereby resulting in quicker weight loss.

Risk factors Lift too heavy weights too often and you can get bulky. Injuries are high in the weight room, but mostly linked to weights being dropped and poor technique.

Circuits

How quickly will it make a difference? After two weeks of twice-weekly circuits.

How many calories does it burn? 476 per hour.

Will it keep me motivated? Circuit training is as challenging (or not) as you make it. You are unlikely to get bored as circuits can constantly change their content and order.

Specific benefits A good circuit addresses every element of fitness - aerobic, strength, balance and flexibility. Ideally, an instructor should introduce new tools - medicine balls, skipping ropes, weights, wobble boards - to make sure you are always developing new skills and testing different muscles.

Risk factors Because the movements are so varied, there are very few risks - unless you perform exercises with poor technique.

Victor: circuits

Yoga v Pilates

Yoga

How quickly will it make a difference? After eight weeks of thrice-weekly sessions.

How many calories does it burn? 102 per hour for a general, stretch-based class. Power yoga burns 245 per hour.

Will it keep me motivated? Yoga is all about attaining a sense of unity between body and mind rather than setting and achieving personal targets. However, you will feel accomplishment as you master the postures and there are many different types to try.

Specific benefits In a study for the American Council on Exercise (Ace), Professor John Porcari found that women who did three yoga classes a week for eight weeks experienced a 13% improvement in flexibility, with significant gains in shoulder and trunk flexibility. They were able to perform six more press-ups and 14 more sit-ups at the end of the study compared to the beginning.

Risk factors Don't fall for the line that celebrities get fit on yoga alone. According to Ace, even power yoga constitutes only a "light aerobic workout".

Pilates

How quickly will it make a difference? After five to six weeks of thrice-weekly sessions.

How many calories does it burn? 170-237 per hour.

Will it keep me motivated? Once you start noticing positive changes in the way you move and hold your body, Pilates is hard to give up.

Specific benefits Widely used by dancers and top athletes, it improves postural awareness and strength. Studies at Queensland University in Australia have shown that Pilates exercises can develop the deeply embedded traversus abdominal muscles which support the trunk.

Risk factors Another study by Ace last year found the cardiovascular benefits of Pilates to be limited. Even an advanced 55-minute session raised participants' heart rates to a maximum of only 62% (below the recommended 64-94% said to constitute an aerobic workout) and was deemed the energy equivalent of walking 3.5 miles an hour. If you have back pain, make sure you see a teacher who is also a physiotherapist, as poor technique can make matters worse.

Victor: Pilates

Spinning v step

Spinning

How quickly will it make a difference? After two to three weeks of twice-weekly sessions.

How many calories does it burn? 408-646 calories an hour.

Will it keep me motivated? Although it's a group session, spinning allows you to test yourself by increasing the workload as you get fitter. Look out for classes with video screens that take you on a virtual ride through pleasant scenery to less gym boredom.

Specific benefits Pedalling works most of the muscles in the legs and buttocks during the pushdown phase so you will get an unbelievably toned lower body. But your heart and lungs are the biggest beneficiaries.

Risk factors Cycling is not a good workout for the upper body, so you would need to include some resistance training. Make sure your seat is positioned correctly to avoid back strain and leg cramps - your extended leg at the bottom of the pedal stroke should be almost straight. Because it is a non-weight-bearing exercise, cycling is not good for strengthening bones.

Step

How quickly will it make a difference? After four weeks of twice-weekly classes.

How many calories does it burn? 510-612 per hour (depending on height of step).

Will it keep me motivated? You will notice changes in your body shape fairly quickly, but there are only so many times you can step on to a platform before utter boredom takes hold.

Specific benefits A study carried out two years ago by researchers at California State Polytechnic University showed that women who did step aerobics three times a week for six months experienced up to 3.3% increases in the bone density of their spines, hip and leg bones. It has good aerobic benefits as well as toning muscles in the bottom and legs.

Risk factors Not recommended for anyone with lower-back or knee problems. The repetitive stepping could aggravate existing injuries.

Victor: spinning