#598: How Do Exercise & Diet Interact to Improve Glycaemic Control? – Jenna Gillen, PhD

#598: How Do Exercise & Diet Interact to Improve Glycaemic Control? – Jenna Gillen, PhD

Author: Danny Lennon March 17, 2026 Duration: 44:24

This episode examines how exercise and nutrition interact to influence glycaemic control, with particular focus on the postprandial period (i.e., the hours after eating) and on "time-efficient" exercise strategies such as low-volume interval training.

Dr. Jenna Gillen outlines the physiological basis for why muscle contraction can acutely reduce post-meal glucose excursions, why repeated sessions can accumulate into longer-term improvements in insulin sensitivity, and why the nutrition context (pre- and post-exercise feeding, carbohydrate availability, and energy balance) can meaningfully alter observed outcomes.

A key translational thread is that many clinically relevant improvements may come from small, feasible doses of activity; especially post-meal walking and brief "exercise snacks" used to interrupt sedentary time.

However, the discussion considers who these interventions matter for most (and least). Postprandial glucose rises are normal in healthy individuals, whereas reducing exaggerated excursions is most relevant for those with insulin resistance, prediabetes, or type 2 diabetes (T2D).

Dr. Jenna Gillen is an Assistant Professor of Exercise Physiology in the Faculty of Kinesiology & Physical Education at the University of Toronto. 

Timestamps

  • [02:42] Dr. Gillen's research focus
  • [04:11] Understanding glycemic control
  • [10:07] Fasted vs. fed state exercise
  • [11:10] Post-meal exercise benefits
  • [20:10] Low volume interval training
  • [26:27] Interval training and blood glucose
  • [31:29] Energy balance and insulin sensitivity
  • [36:32] Exercise and nutrition interactions
  • [40:11] Practical exercise recommendations
  • [43:56] Key ideas segment (Premium-only)

Links


Sigma Nutrition Radio, hosted by nutrition scientist Danny Lennon, moves beyond the noise of diet trends and simplistic advice to explore the complex, fascinating world of human nutrition. This is a space for deep, evidence-based conversations that acknowledge the nuance and often contradictory nature of scientific research. Each episode delves into a specific topic within health, fitness, or dietetics, breaking down the underlying physiology, examining the latest studies, and discussing practical implications with expert guests. The goal isn't to hand out rigid meal plans but to cultivate the critical thinking skills necessary to navigate the ever-changing landscape of nutritional science. You'll hear detailed analyses of how research is conducted, thoughtful debates on contentious issues, and explorations of how evidence translates-or doesn't-into real-world recommendations for different individuals. Tuning into this podcast means committing to a more sophisticated understanding of how food, movement, and metabolism interact, leaving you better equipped to make informed decisions about your own health and skepticism towards the next big headline. Danny’s approach is both rigorous and accessible, making even the most detailed biochemical pathways relevant to everyday life. It’s for anyone who has ever wondered about the real story behind a nutrition claim and values substance over soundbites.
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