| On Twitter, I asked for some newsletter topics, and these are just a few of the suggestions I got. I figured I’d do a rapid fire Q&A for this week’s Sunday with Sisson. “Ocean farming shellfish” Big fan of ocean farmed shellfish. The beauty of the ocean farmed oysters and mussels is that they live exactly as their wild counterparts live. They eat the same things, they filter the same water (which is why farmed bivalves are so important for ocean health), they are just a more reliable harvest. I love the idea of backyard or guerrilla oyster farms. “Managing hunger after swimming” Swimming is a notorious hunger booster. You go for a swim and you feel like you could eat three meals immediately after. That’s one reason why a lot of the lap swimmers you see at the pool are chubby even though they’re always there putting in those laps. What’s going on? Swimming is full body training—it hits the heart and the muscles. You’d think it would be a big enough stimulus to overcome the negative effects of big meals. But for most, it’s not. And there are two reasons. One problem is that people do this leisurely swimming pace where they do 30 or 40 laps going really nice and easy. While that kind of low-level movement is great for improving fat oxidation in your muscles and cells, it’s not enough of a stimulus to justify eating a huge meal after. It’s also about the body temperature maintenance. Even if the water doesn’t feel cold, it’s still lower than your body temperature, and it’s forcing you to burn through energy to stay warm and maintain body temperature. Later, your body wants to replete all that lost energy, so it starts sending massive hunger telling you to eat. This is why walking and easy jogging in that aerobic zone are so great for body composition: you’re not in the water, and you don’t have to fight to conserve body temperature. You can do that at a super low level and you’re not famished afterwards. So here’s a solution. You swim faster. You swim harder. You sprint in the pool. You should feel a pump. Your lats, biceps, triceps, pecs, quads, and hamstrings should burn. You should be out of breath. You should be sore the next day. You should need a rest. Basically, you need to justify the hunger. “Is there a difference between the results of aerobic and high-intensity exercise?” There is. While both sprint training and submaximal aerobic training improve VO2 max and general fitness—low level cardio makes you better at sprinting and sprinting makes you better at low level cardio—there are specific adaptations. Basically, training in the aerobic zone makes you better at everything but especially better at aerobic zone activity. Sprinting makes you better at everything but especially better at sprinting. A recent paper shows this. One group of adults ran 5 to 10 near maximal 30-second sprints three times a week. Another group ran 30 to 60 minute low level aerobic sessions three times a week. After the intervention, they did a series of aerobic and sprint tests. The sprint group was able to jog at a higher speed without their heart rate spiking as high as when they started, but their aerobic improvements weren’t as impressive as the aerobic group. The aerobic group got better at sprinting, but after the 4th sprint their performance really dropped off, whereas the sprint group was able to maintain their performance through the 5th sprint. Lesson? You should train both—but one is better than nothing and will help across the board. | 
