With only a small body of scientific research available, one expert parses out why ketones might not be runners’ magic bullet ...

In the current study, the hearts of all 13 of the participants were working more efficiently after the ketone drink at rest and during moderate intensity exercise, compared to the placebo drink.

This result may mean that ketone buildup is starting. You should test again in a few hours. Drink plenty of water prior to the test. Don’t exercise if your blood glucose levels are also high.