You don't know when a bear market might hit your retirement fund, it could be at the worst time, because of this, it's important to divide your retirement fund into 3 buckets: now, soon, and later.
How to put money into different buckets?
The "Now" bucket holds money you will need in the short term and should be held in savings account. It along with your social security benefits and pension should cover your basic living needs for up to a year. It should also have enough cash for unexpected or expected major expenses.
The 'Soon" bucket will be your source of income for the next 10 years. It's better to invest in a fixed annuity or high quality short term bonds. As the Now bucket fund is depleted, you withdraw money from the annuity or sell some of the fixed income investments to replenish it.
The "Later" bucket holds money invested in more aggressive stock funds and won't be needed for a decade. This bucket can also include life insurance or a deferred-income annuity, which pays income later in life. Sell funds from this bucket to replenish funds in the "Soon" bucket about 5 years before it runs out of money. If the market is in a downturn, you can wait a few years for such replacement.