Bad news for swimmers: your excursions up and down your local pool might not be doing as much for your body and fitness level as you think.
Swimming experts say a lot of people who go to the pool and splash around or plod along the lanes might be relieving their stress and improving their joint health and mobility, but is unlikely they are getting a worthwhile cardiovascular workout.
Associate Professor Heather Smith from the University of Auckland says the amount of swimming required to maintain an existing level of fitness is the same as for any other exercise - three half-hour sessions a week. But the key is the intensity. While swimming is good, low-impact exercise and can work all the muscle groups, just floating around in the pool will have limited effect.
Smith says swimmers often find it hard to gauge how hard they are working. "Most people can tell the difference between walking and jogging but with swimming it's a bit different in that you have to push your own effort." She says swimmers should aim to be breathing fairly hard at the end of their workout.
Swimming coach Hayden Woolley says how effective swimming is as an exercise depends on the skill level of the swimmer. "Theoretically it works every muscle in the body but it almost entirely comes down to the way you train. A good swimmer might say it is phenomenally good exercise but if you are not so good you struggle to get enough lengths [to get fit]."
Woolley, who runs the official training programmes for the annual Ocean Swim series, agrees a lot of people start training without structure. "They just push, push, push with bad form and don't vary anything." That lack of variation means they do not work their aerobic systems as well as they could, and do not get to adapt their technique.
Having a goal, such as a harbour crossing, to work towards helps focus. But Woolley says that a lot of people overestimate their abilities and do not have training that accurately reflects that goal. "They might be training for a 3km swim but the longest they'll do in the pool is 1500m, or they'll get into it and realise they should have worn a wetsuit, or discover 'my wetsuit is choking me, I will have to pull out'."
He says, six weeks out from this year's first ocean swim, people who already have some level of fitness will be able to train to compete. They need to add to the distance they swim in the pool and have a trial run in the sea. New swimmers need six months to a year to prepare, so should aim for next year's events.
Belinda Galley, of Swimming New Zealand, says people go wrong when they do not think about swimming in the same way they would approach going to the gym. "Swimming is the sort of activity that is as hard as you want to make it."
She recommends swimmers get a programme written up by a professional. "Then you can work on specific areas you want to target." She has worked in swimming schools where she has encountered swimmers who have been coming to the pool for years, doing the exact same thing every time. "I would tell them to take the time to go to a school or swimming club and get someone to give them a programme."
Try out some different activities to mix up training and to isolate different body parts, for example sprints or kicking exercises. Pop on some hand paddles to increase the resistance on your upper body or use a pool buoy. If you want to lose weight, interval training can help. Swim as fast as you can for five minutes, then take it easy for two, then repeat. If you are new to the pool, build up by working in bursts, adding lengths or minutes as you find your stamina improves.
State NZ Ocean Swim Series event organiser Scott Rice says: "One of the great things about this series is that anyone, with the right amount of training, can give it a go. Our aim is to encourage as many Kiwis as we can to take up swimming to increase their general health and fitness. Just like running a half-marathon, it is imperative that a balanced training regime is followed prior to taking part in one of our events."
Out to sea
The State New Zealand Ocean Swim Events calendar 2011/2012
State Harbour Crossing, Auckland (2.9km swim only) Sunday November 13, 2011
State Paihia Classic, Bay of Islands Saturday December 10, 2011
State Capital Classic, Wellington Sunday January 29, 2012
State La Grande Swim, Akaroa, Canterbury Sunday February 19, 2012 Christchurch
State Sand to Surf, Mt Maunganui Saturday March 10, 2012
State King of the Bays, North Shore, Auckland Saturday March 31, 2012