Social media has been gripped this past week by a so-called 'ice bucket challenge', whereby celebrities from varying professions have freezing cold ice water poured over them before nominating colleagues to do the same. The challenge has raised millions to fight Lou Gehrig's disease, and has been particularly popular with footballers. Earlier today Chelsea captain John Terry nominated former manager Rafael Benitez for the challenge, while forgotten Manchester United midfielder Anderson has pulled a similar stunt by selecting legendary retired boss Sir Alex Ferguson to have a bucket of the cold stuff tipped upside his head. We've already seen countless of these videos on social media recently but this one, this one is slightly brilliant. Of course, all ALS ice bucket challenges are worthy, but Anderson's stands out from the crowd. First, keep a close eye on Shinji Kagawa's reaction when he is nominated:He looks pretty amused when Ferguson is nominated, but when he hears his own name said allowed, his face just crumbles. There's a man who does NOT want a bucket of ice water tipped over his head. This video is also brilliant because it completely puts paid to those unflattering rumours that Anderson is overweight - he just isn't, and that is a negative image he will now hopefully shed. ALS, commonly referred to as Lou Gehrig's disease, is a progressive neurodegenerative disease that effects nerve cells in the brain and spinal cord. With voluntary muscle action progressively affected, patients in the later stages of the disease may become totally paralyzed, and the progressive degeneration of the motor neurons in ALS eventually leads to their death. A little over 5,600 people in the U.S. are diagnosed with ALS each year. It is estimated that as many as 30,000 Americans have the disease at any given time.