Effect of short-term exercise training on insulin sensitivity in obese and lean mares.

This research investigates the influence of short-term exercise on insulin sensitivity in obese and lean mares. The study concludes that even a brief period of exercise can improve insulin sensitivity in both obese and lean mares, irrespective of change in body weight.

Methodology

• The study used twelve untrained, aged mares and divided them into categories based on weight (obese and lean) and physical activity (exercised and sedentary).
• Exercise for the relevant groups was set at a trotting pace, not exceeding a heart rate of 140 beats per minute, for a span of 30 minutes.
• Three euglycaemic hyperinsulinaemic clamps were carried out on each group at various stages. These tests were done before the exercise training (P), 24 hours after the final exercise session (E), and 9 days following the exercise training (PE).

Key Findings

• Before the study, it was confirmed that the obese mares were insulin-resistant relative to the lean mares, as expected.
• No significant change was seen in the mares’ bodyweight or condition regardless of their starting state or the introduction of exercise.
• In terms of Glucose Infusion Rate (GIR), both the obese and lean exercised groups exhibited higher rates after exercise.
• Insulin sensitivity in both exercised groups returned to pre-exercise levels by the 9-day post-exercise mark.

Conclusions

• The authors suggest that even short-term light exercise can improve insulin sensitivity in mares, both obese and lean.
• This improvement in insulin sensitivity did not necessitate a long duration of training or any major shift in body weight.
• However, the improvement upon exercise seems temporary, as after a span of 9 days, insulin sensitivity regressed to its original state.