Chad Waterbury asks the question:
Ori, throughout the majority of my career I’ve recommended fast-acting carbs with protein powder in the post-workout meal in order to get an insulin spike and shuttle amino acids into the muscles for growth and repair. But after consulting with you I’ve realized that I might have been wrong with this approach. Can you explain the problems with ingesting simple carbs such as raisins or cherry juice immediately after training?
Ori Hofmekler answers:
First off, after training your muscle becomes temporarily insulin resistant. That’s due to tissue micro-injuries which impair the mechanism that utilizes glucose in your muscle. Putting a high glycemic fuel in your muscle right after exercise will jeopardize energy utilization and disrupt your insulin sensitivity. High glycemic fuel includes all kinds of sugars, dried fruits and refined flour.
One of the biggest misconceptions is the idea that an insulin spike is necessary for boosting protein synthesis in the muscle. The truth is quite different. The real factor is not insulin spike but rather insulin sensitivity. It has been proven that as long as insulin sensitivity is high, even low (fasting) insulin levels along with amino acids will be sufficient to trigger mTOR/AKT – the cellular pathway that deposits protein in the muscle towards repair and growth. Overly spiking insulin with simple carbs immediately after exercise impairs insulin sensitivity and diminishes your capacity to sustain a healthy metabolism and a lean, strong physique.