He has been tested for diabetes twice, with negative results.

Herds should be tested once or twice a year to maintain the health and keep out the disease.

If 70 to 100 players were caught (some may have tested positive twice), many more are likely to be using steroids, scientists said.

Last year, all players on 40-man major league rosters were tested twice within a week.

Note however that an increase of statistical power comes at a price: more tests are required, each subject having to be tested twice.

He has had a problem with drugs in the past but was twice tested recently and was clean both times.

Officials said he had twice tested negative for drugs.

She was tested twice, once on 5 August and again the following day after she had finished first.

The Pentagon has twice tested components of a system to knock down a missile in space.

Players would be tested twice in season for amphetamines and subject to random testing.