A person’s body type — somatotype — used to be defined in simple terms: ectomorphs are thin, mesomorphs are muscular and endomorphs tend to hold onto extra weight easily.
But it turns out it’s much more complicated than that. In addition to basic outward appearance, the three somatotypes also offer insight into how your hormones and sympathetic nervous system react to stressors like food and exercise and how your body reacts to specific macronutrients.
Each body type has serious strengths, and you can tailor your training and nutrition to exploit those while working on your weaknesses.
Before we dive into each body type, it’s important to remember our body types do not define us. Tailoring your training to your somatotype simply gives you ways to efficiently train for your goals. “It’s about doing these small things to maximize performance in the sport you love,” says Stacy Sims, PhD, a renowned exercise scientist and author of ROAR.
Strength: “You’re likely long-limbed and lean, and lots of top runners are ectomorphs,” says Sims. “It’s great for sports that require you to move your body over long distances, because the less body weight you have, the less strain on the body.”
Weakness: While this might be the most ‘runner-friendly’ type at a glance, it still has its challenges. “You don’t have a lot of muscle, so you don’t have a lot of protection for the joints, and you can’t develop power easily, so you can’t sprint as well,” says Sims. It’s also easy to get into a lazy habit since you won’t put on a lot of visible body fat even if you don’t eat healthy. It’s easy to pay less attention to a healthy diet — a lot of them end up not being as healthy as the other body types because they aren’t as concerned about weight, but diet isn’t just about maintaining a healthy weight, it impacts the gut microbiome and other markers of health.”
Nutrition tip: While you can eat pretty freely without putting on weight, you should still focus on a whole-food diet that includes healthy fats and high-quality protein, along with carbohydrates. Being an ectomorph is not a free pass to eat fast food at every meal — in fact, you’re almost at a disadvantage because you can’t see the results of an unhealthy diet, but you will feel them eventually.
Tailor your training: More than any other body type, you need strength training to increase muscle mass to increase power, but more important, decrease injury risk, says Sims. She doesn’t mean you need to become a gym rat, though: “Just 10 minutes of plyometrics with your body weight doing things like box jumps, three times a week, is enough to help preserve bone density and retain mobility and muscle health.” But if you want to add some muscle, consider a more intensive strength-training program.
Strength: “This is someone who looks at a kettlebell and, boom, puts on muscle,” says Sims. “I’ve noticed that in ultra-endurance, like Ironman triathlon, a lot more mesomorphs are winning because they can put on muscle and have the strength, plus the ability to do that long distance without breaking down or getting injured. It’s also great for sprinting, more explosive sports.” Because of your natural muscular build, you also are less prone to injury.
Weakness: “It’s also easy to bulk up as a mesomorph. If you want to be a hill climber, that extra weight — even though it’s muscle — can work against you,” Sims says. This body type, especially for men, can mean a struggle when trying to add more volume to a training plan: It can be done, but your extra muscle forces your body to do more work than an ectomorph has to do to cover the same mileage.”
Nutrition tip: Precision Nutrition’s John Berardi, PhD, recommends sticking to the ‘mesomorph meal,’ which balances the three macronutrients fairly evenly: a serving of protein, fat and a complex carbohydrate (like potatoes) plus a serving of vegetables (like spinach) makes up an ideal meal. You don’t need to overdo it on any one macro.
Tailor your training: If you’re training for track-style sprinting events, you don’t need to change much since you’re naturally adept at these explosive speeds. But if you’re trying to do more marathon-style endurance events, you may want to shift to bodyweight-levels of strength training to avoid putting on more muscle (Sims recommends Pilates or yoga for mesomorphs), and focusing on adding volume and easy running — just make sure you’re not adding too much volume too quickly.
Strength: You store energy easily, so you might find activities like long-distance hiking or ultra-distance running work well for you — a lower metabolism may actually be helpful on a thru-hike where food supply is limited. Most power-lifters fall into the endomorph category, so while you tend to hold on to weight easily, you can also translate that weight into muscle instead of fat. Sims also reminds us that being an endomorph doesn’t automatically translate to being overweight, which is a popular misconception. Rather, it refers to the body type that has a slower metabolism and is just more prone to storing body fat.
Weakness: Because of that, “Endomorphs put on body fat more easily, and you’re more likely to hold weight around your hips and thighs,” Sims says. This can make running more difficult for myriad reasons, from general comfort (thigh chafing can be a huge limiter for newer runners) to figuring out how to fuel for working out without gaining weight.
Nutrition tip: Ectomorphs are actually at risk of under-eating, says Sims. It’s a common issue: To combat weight gain, an endomorph may try to drop calories, but that calorie restriction doesn’t actually help with weight loss. “It’s about eating and fueling for what you’re doing,” she adds. You may want to focus more on high-quality proteins and fats and get more of your carbohydrates from vegetables, but don’t ditch carbs altogether, especially if you’re training a lot.
Tailor your training: “You can absolutely still be a fast runner with an endomorph body type,” says Sims. Get into the gym and add strength training to your routine to shift your body composition to more muscle — it may be easier for you to shift from fat to muscle versus strictly dropping pounds, and it will help your running at the same time.