The Claim

In adults with type 1 diabetes using multiple daily insulin injections, performing resistance exercise in a fasted state in the morning results in significantly higher mean glucose levels (9.63 mmol/L) and greater time above range (>10.0 mmol/L, 44.4%) over the 6-hour post-exercise period compared to performing the same exercise in a fed state in the afternoon (8.44 mmol/L, 26.3%), indicating that feeding status is a stronger determinant of post-exercise glycemic control than time of day.

Source: A Comparison of the Effects of the Timing of Resistance Exercise on Glucose Levels Within the Target Range in People With Type 1 Diabetes (TREX Study): A Randomized Crossover Trial

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
69score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

In adults with type 1 diabetes who use multiple daily insulin injections, resistance exercise done in the morning while fasting leads to higher blood glucose levels and more time spent with blood glucose above 10.0 mmol/L over the next six hours than the same exercise done in the afternoon after eating.

See the scientific wording

In adults with type 1 diabetes using multiple daily insulin injections, performing resistance exercise in a fasted state in the morning results in significantly higher mean glucose levels (9.63 mmol/L) and greater time above range (>10.0 mmol/L, 44.4%) over the 6-hour post-exercise period compared to performing the same exercise in a fed state in the afternoon (8.44 mmol/L, 26.3%), indicating that feeding status is a stronger determinant of post-exercise glycemic control than time of day.

Why this might work

When a person eats before exercising, insulin rises and tells muscle cells to take in more sugar from the blood, while also telling the liver to stop making and releasing sugar. During resistance exercise, muscle contractions further pull sugar into muscle cells. Together, these actions keep blood sugar from rising too high. Without food before exercise, insulin stays low, the liver keeps releasing sugar, and muscles cannot pull in enough sugar, so blood sugar climbs.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: A Comparison of the Effects of the Timing of Resistance Exercise on Glucose Levels Within the Target Range in People With Type 1 Diabetes (TREX Study): A Randomized Crossover Trial

    For people with type 1 diabetes who use insulin injections, working out in the morning without eating raises blood sugar more than working out in the afternoon after eating — what you eat before exercise matters more than when you do it.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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