As bonds are redeemed, you redeploy the money at the new higher rates.

FORBES: Magazine Article

There would be no sacrifice by German taxpayers, as the hard assets would gradually be sold, whereupon the bonds would be redeemed.

ECONOMIST: Letters: On the euro zone, Irish banks, India, veterans, women, jobs, seasteading, Vladimir Putin | The

Congress spent these surpluses, and the U.S. Treasury issued the Social Security Trust Fund special bonds, which can be redeemed whenever the Social Security system has a current account deficit.

WSJ: Thomas Saving: Obama's Debt-Ceiling Scare Tactics

And buyers of index-linked bonds have protection against deflation, since they will always be redeemed at their face value or higher.

ECONOMIST: A very unusual sign of confidence in economic policy

Lottery bonds are a type of government bond that has a chance to be randomly redeemed at a value that is higher than par value.

FORBES: 3 Bonds You May Have Never Heard Of