If you're wondering how to improve your fitness fast, know this - most effective training plans and respectable personal trainers will advise that, to see results, you need to be working out consistently and stick at it for at least three months. That said, there's been some unexpected news this week: some research does show that you might be able to alter your fitness levels much sooner than initially thought.
One study from the Journal of Physiology found that six sessions of HIIT performed over two weeks improved exercise performance, while another NASA study showed that just eight sessions were enough to improve markers of fitness.
