Tim's answer about a level of 1 is fine. I suspect it may be exercise induced but to be on the safe side you do need to make sure. (you could be going down with a bug )
Keep a check on both glucose and ketones to make sure that the ketones go away and certainly aren't rising (obviously take appropriate insulin )
Being worried at much lower levels than those suggested on the graph above hasn't much to do with popular belief quite the opposite. (where did the graph come from?)
People with T1 do not have the feedback loop that people with insulin have and therefore ketones can increase very rapidly
This is from the 2014 guidelines for DKA from the
International Society for Pediatric and Adolescent Diabetes
Definition of diabetic ketoacidosis (DKA)
The biochemical criteria for the diagnosis of DKA
are (17):
• Hyperglycemia [BG>11 mmol/L (≈200 mg/dL)]
• Venous pH<7.3 or bicarbonate<15 mmol/L
• Ketonemia* and ketonuria
*Although not universally available, blood β-hydroxybutyrate (BOHB) concentration should be
measured whenever possible;
a level≥3 mmol/L is indicative of DKA (18).
Urine ketones are typically≥2+(‘moderate or large’) positive. Partially treated children and children who have consumed little or no carbohydrate may rarely have only modestly elevated BG concentrations, referred to as ‘euglycemic ketoacidosis’ (19, 20).
If you also check the research on this done with adults you will find similar reported levels.
http://www.ncbi.nlm.nih.gov/pubmed/15660743 (several other similar studies in sidebar)
