Some exercise physiology studies show quick improvement in athletes introducing just a few weeks of 30-second intervals. Does that mean all athletes might benefit from applying the principles of speed development? The answer could have major implications for how you think about structuring a training week.
A perfectly designed training program might aim to have ideal intensity distributions. But what happens to a perfect program when you add hills? The answer to that question can lead to fitness breakthroughs... or collapses.