The study also found that most workers find themselves struggling at this point up to three days a week. A warm working environment, not enough sleep the night before and the sheer volume of their workloads emerged as the most common reasons for the slump. Dehydration and eating too much at lunch were also found to contribute to British workers ‘hitting the wall’ in the afternoon. Chris Arrigoni, Director and Co-Founder of Get More Vitamin Drinks which commissioned the study, said: “Your working environment really will contribute to your productivity. “So it maybe isn’t too much of a surprise that a warm office sends many workers into a downward spiral after they’ve eaten their lunch.