Your Qs: Choosing an elliptical, giving blood, and how much protein you really need.
Q1: How do I know which elliptical machine is best for me?
My gym has a few different types of elliptical trainers. What are some of the key differences between them, and how do I know which one is best for me?
A. Elliptical trainers can spare your joints and work your whole body. Proper fit is essential, however. That’s because ellipticals move your limbs along preset tracks, and not every machine fits every exerciser. “It’s important to find a model that’s comfortable for your particular height and structure,” counsels Jeff Rosga, director of education at Life Time Academy, the education division of Life Time. Some key features to consider:
Stride mechanics. Your hips should hyperextend while working the pedals — meaning your feet should push behind you slightly, as in a typical walking or sprinting motion. If your feet stay in front of your hips throughout the movement, choose another model.
Drive position. Front-drive ellipticals have an enclosed plastic casing on the face of the machine and the pedals follow a fixed, back-and-forth movement.
Rear-drive models (with the casing in the back) have pedals that move up and down slightly. These rear-drive units allow you to change the shape of your stride and, as a result, the muscles you’re working the hardest by inclining or declining a ramp in the front of the machine.
Both models can provide a great workout; it just depends on whether you prefer more of a walking or climbing movement.
Upper-body action. Many elliptical units have upper-body resistance bars. If you choose to use them, go with a machine whose handles offer plenty of resistance, so that your upper body gets a good workout.
Whichever model you choose, Rosga suggests you shake up your cardio workouts frequently to avoid getting bored or injured.
Q2: Will giving blood affect my athletic performance?
I give blood occasionally and have heard that doing so can have a short-term negative effect on athletic performance. Is this true?
A. Common sense says you should allow your body time to recover after giving blood. The big question is, how much time?
There are two concerns for athletes, say experts: reduced oxygen delivery to muscles and dehydration.
A typical blood donation is a pint, and its absence decreases oxygen delivery to your muscles by about 10 percent. Although it can take your body a month to replace those blood cells, the average athlete is unlikely to notice an effect.
When you engage in moderate activity levels, 90 percent oxygen-delivery capacity is still more than enough to meet your increased need. Still, says sports medicine physician and Ironman triathlete Jordan Metzl, MD, it is probably best not to give blood on the same day as an athletic event.
The bigger concern for athletes, Metzl warns, is dehydration. If you’re a little under-hydrated before giving blood, it’s possible that the additional fluid loss could dry you out enough to slow you down afterward. Listen to your body.
For elite endurance athletes, the calculus changes: A study of competitive cyclists found that while submaximal performance was unaffected by blood donation, maximal performance was compromised for up to a week. So if intense competition is in your future, err on the side of caution and avoid giving blood within at least seven days of an event.
Q3: How much protein do I really need?
Every now and then I eliminate meat from my daily diet. When I do, people warn that I might not be getting enough protein. Is this something I should worry about?
A. “Protein intake depends entirely on your goals,” says Alan Aragon, MS, nutritional adviser to some of the top pro athletes on the West Coast. Though diet gurus often give blanket recommendations for how much protein people need, actual requirements can vary tremendously from one person to the next. (Aragon notes that the longest-living people on Earth, the residents of the so-called Blue Zones — places like Okinawa and Sardinia — actually consume relatively little protein.)
Those who seek general health and longevity but don’t exercise intensely can probably do fine on any clean, healthy diet — vegetarian included — assuming it contains at least 50 to 60 grams of protein a day. You can get that from one or two servings of meat or poultry, or a few hearty servings of beans or tofu. As your activity level goes up, protein requirements do increase sharply.
“Sedentary adults who take up strength training three times a week should probably double their protein intake, especially if they were [consuming] at or below the RDA levels of 0.8 grams per kilogram [or 2.2 pounds] of body weight,” Aragon says. And people who participate in intense physical activity most days of the week will gain the most strength and muscle on about a gram of protein per pound of target body weight every day.
While it’s a bit harder to get that much protein without eating animal products, it’s doable. In addition to the usual beans, nuts, and grains, vegetarian gym-goers should consider loading up on whey, casein, and other protein powders to ensure adequate recovery between workouts. (Find protein-packed vegetarian recipes in “The Hearty Vegetarian.”)
Regardless of how much protein you consume, though, don’t forget that fruits and vegetables rock. The fiber and phytonutrients they contain help stave off cancer, cardiovascular problems, and digestive diseases of all kinds. So go easy, moderate, or heavy on animal proteins as you see fit — but never neglect the green stuff.