If you’ve ever thought about an adventure tour trekking to Mount Everest basecamp, hiking Machu Picchu or skiing the Swiss Alps, you may be wondering how you will fare in the higher altitude.

Deficiency in any of the B vitamins can mean trouble for your health. The B vitamin that people (women in particular) are most commonly deficient in is B12. In part, this is because the human body cannot produce its own B12, but must rely on food sources to obtain it.

When it comes to fitness training, there is no end to the number of theories and techniques espoused by all the various professionals and gurus out there. And for every training method, it seems that there is a large following that swear by the technique but others for whom it does not seem to work at all. High-Intensity Interval Training (HIIT) is no exception. So why does a training technique that works for so many, prove ineffective for some? The answer is in our genes.