There are typically two reasons why someone might want to do cardio work; to increase fitness, or to lose weight.
Probably the most abused aspect of training in the new year is cardiovascular exercise, and chief amongst that is running.
There is a mistaken assumption that cardio, and in particular running, is the best means for weight loss available. It isn’t, and that’s something I’ll be looking at next week.
In the short term cardio can benefit weight loss. But in the long term, as your body adapts to the exercise, the weight loss effect is reduced. Therefore you need to work harder or longer to have the same effect. This is why there are very fit cyclists across London who are still overweight. They might cycle twenty kilometres a day but because they do it every day their bodies have adapted to it and they hardly burn any additional calories from it.
Cardio does have a benefit for weight loss. And if you are thinking about using it as part of a weight loss strategy then I would recommend a maximum of twenty minutes a day with a ratio of double the time spent doing resistance training to doing cardio.
If you’re doing cardio for fitness then this prescription changes dramatically. There are clear and obvious benefits to doing sports specific and non specific work. I would say that, as a minimum, if you aren’t training for fitness in your sport then you won’t get very far; if you are a runner then you should run, and if you are a swimmer then you should swim.
There is much carry over to be made from non specific sports training as well. For example a conditioned runner might find it hard to work for a sustained period in the high exertion percentages, but put them on a bike or in the pool and because of the unfamiliar activity it becomes possible, and that can carry over. It’s not something that should be exclusively done, but it does benefit. The vast majority, however, should be sports specific.
That doesn’t mean duration specific though. There are no athletes who are running a series of 10k runs in preparation for a 10k run. Mo Farah doesn’t do loads and loads of marathons to get ready for a marathon.
He will focus around various variables, such as intensity, elevation, surface type, stride length, step cadence and recovery in order to improve his overall time and ultimately his long distance run fitness.
If you are working towards a fitness goal then I’d say that as a minimum you should be doing three sessions a week towards your goal and hitting the total distance you’re working towards as a minimum weekly output level once you have gone through a conditioning phase. I believe that mobility, resistance work and recovery work are vital to long term injury free success. You are therefore looking at four to five sessions per week, or three to five hours work a week, as a minimum.