Susanna Soberg

The Soberg threshold for thermal health Dr. Andrew Huberman highlights the transformative research of Susanna Soberg, which identifies a specific weekly "threshold" for thermal exposure. To trigger real physiological shifts, aim for at least **11 minutes of cold exposure** and **57 minutes of sauna** per week. These minutes don't need to happen in one grueling session; they can be spread across multiple days to accumulate the metabolic benefits. Tools for thermal cycling To get started, you'll need access to a sauna (ideally between 187°F and 212°F) and a cold source like an ice bath or cold shower. The goal is to reach a temperature that feels safe but makes you want to get out immediately. This discomfort is the signal your body needs to adapt. Step-by-step contrast protocol 1. **Heat first**: Enter the sauna for 15-20 minutes to raise your core temperature. 2. **Transition to cold**: Move directly to the ice bath for 1-3 minutes. 3. **Repeat the cycle**: Perform 2-3 rounds for maximum resilience. 4. **End on cold**: This is the "Soberg Principle." Ending with cold forces your body to generate its own heat, sparking a thermogenic response that boosts metabolism long after you leave the water. Maximizing growth hormone If your goal is recovery, Huberman suggests a specific protocol: do the sauna once a week for four sets of 30 minutes, separated by short cooling breaks. This high-stress stimulus has been shown to increase growth hormone by up to 16-fold. Tips and troubleshooting * **Timing matters**: Do cold exposure early to wake up; use heat at night to facilitate a temperature drop that aids sleep. * **Stay safe**: Heat can be lethal if you are dehydrated. Always prioritize salt and water intake. * **Fertility warning**: Constant high heat can reduce sperm counts. If you're trying to conceive, limit intense sauna sessions or use cooling packs.