Hi Lucia,
If you want to strengthen legs try using a kick board with your arms in front. Do a few leanghths with it and you will feel it on the legs. Use it like a glide at first and when you need more resistance flip it on its side so you are in effect pushing it forward. Do a few leanghts then a break - normal swimming - then a few more. Build up slowly and try to incoporate it into a set.
Regards Feargus
If you want to strengthen legs try using a kick board with your arms in front. Do a few leanghths with it and you will feel it on the legs. Use it like a glide at first and when you need more resistance flip it on its side so you are in effect pushing it forward. Do a few leanghts then a break - normal swimming - then a few more. Build up slowly and try to incoporate it into a set.
Regards Feargus