No. It is often wrongly assumed that jobs that are traditionally done by women are 'lighter'. In fact, women are at as much risk as men from manual handling injuries.
Advice from the GMB union says: “Women employees should not be asked to lift the same weights as their male counterparts without a specific assessment of the work involved. As a rule of thumb, women workers should only be expected to lift two-thirds the weights of their male counterparts.”
However, the GMB says there is such a 'wide overlap' between the sexes that there is no point in trying to identify tasks that 'only men' should do. If a load is too heavy for a fit woman to handle, it will be equally dangerous for a large number of men. Some jobs require particular fitness, height or strength. But, in general, employers should aim to fit the work to the worker, and not the reverse.