At what blood glucose levels would the body have difficulty utilizing glucose for exercise?

The body typically has difficulty utilizing glucose for exercise when blood glucose levels fall below 70 mg/dL. At this level, known as hypoglycemia, sufficient glucose for energy is not available to meet the physiological demands during physical activity. The body relies heavily on glucose for fuel, particularly during high-intensity exercise, and low levels can impair performance, leading to symptoms such as fatigue, dizziness, confusion, and weakness. This indicates that blood glucose levels are critical for maintaining energy levels, especially in the elderly, who may already have compromised metabolic responses.

In contrast, blood glucose levels between 70 and 250 mg/dL are generally considered safe and normal for exercise, as this range provides an adequate supply of glucose for energy. Levels above 250 mg/dL are indicative of hyperglycemia, which can also impair exercise performance but in different ways, primarily through dehydration and the body’s metabolic response to stress. However, hypoglycemia is the more urgent concern during exercise, making the identification of levels below 70 mg/dL crucial for ensuring a safe and effective workout in older adults.