Want to fuel smarter, train better and improve your sports
nutrition knowledge? Then keep reading! Here's some of the
research presented by exercise physiologists, nutritionists and
other health professionals at the American College of Sports
Medicine's annual meeting (Denver, May, 2006). Childhood obesity
The rapid increase in childhood obesity is worrisome because so
many obese kids are developing diabetes and heart disease--
conditions associated with old age. One solution is to add
exercise back into daily life. A safe and socially accepted
way to do this is to organize a Walking School Bus in your
neighborhood; a parent or hired college student chaperones the
group of children.
Exercise can also be added into the school curriculum, but
many schools are reluctant to do so. The assumption is less
class time will contribute to lower test scores. Not the case.
When students ate a free school breakfast, participated in 15
minutes of teacher-led activity each morning, and had mid-day
recess before lunch, their test scores improved plus the
teachers had 58% fewer discipline referrals.
Weight
* Two contributors to undesired fat gain are sugar-sweetened
soft drinks and a sedentary lifestyle. Contributors to
successful fat loss include weekly weigh-ins, at least 30
minutes per day of (ideally, supervised) exercise, and daily
food records. Standing more often also helps with weight
management. That is, obese people--who tend to sit 2.5 hours
more per day than their lean counterparts--can potentially save
350 calories per day. Get rid of the chairs?!
* Yes, achieving a healthy weight is important. But the desire
to get too thin can lead to health problems. Among 80 varsity
high school athletes at an all-girls school, 74% had at least
one component of the Female Athlete Triad--a syndrome with loss
of menstrual periods, disordered eating and stress fractures.
Fifty-five percent ate inadequate calories, 30% had a history
of amenorrhea, and 19% a history of stress fractures. Is "thin
at any price" worth the cost..?
Body image
While you are exercycling at the gym, be forewarned: If you
look at magazine ads with ultra-fit bodies, you may experience
increased anxiety and depression and a change of mood. Choose
your magazines carefully!
Fueling for exercise
* If you are doing all-day exercise, plan to routinely snack
more than eat meals. Forest firefighters who snacked all day
consumed more calories, hence were able to be more active, than
those who ate standard meals.
* Does it matter if you fuel yourself pre-exercise with carbs
that are slowly or rapidly available (oatmeal vs white toast)?
Two studies suggest no. Your best bet is to eat what settles
comfortably and helps you perform well.
Fluids
* Being dehydrated can not only change your mood but also hurt
your performance. For example, basketball players who got
progressively dehydrated performed progressively worse with
shooting and sprinting drills. Drink well!
* Cyclists who replaced only one-third of their sweat losses
during an 80-kilometer time trial were four minutes slower than
when they drank ad lib, according to thirst. Don't restrict
fluids.
* Even swimmers need fluids; elite swimmers might lose
about .85 liter/hour but generally fail to replace that loss.
* Cyclists who drank enough plain water to replace 90% of the
sweat losses incurred while riding for two hours in the heat
developed lower blood sodium levels- and a higher risk for
hyponatremia. Better choice: a sports drink with sodium.
* Should your sports drink contain protein? Debatable. Protein
changes the flavor, so athletes tend to drink less; sub-optimal
hydration could hinder performance.
Protein for recovery
* The jury is out whether protein (or amino acids, the building
blocks of protein) added to a sports drink enhances
performance. But consuming a carb + pro beverage before or
right after a muscle damaging workout does reduce post-exercise
muscle soreness. Runners who took branch-chain amino acids
(that readily convert into glucose for fuel) before and after
each of three daily bouts of hard exercise reported less muscle
soreness and fatigue. The researchers attributed this to having
less muscle damage and inflammation.
* Does the amino acid taurine enhance energy? Doubtful. When
cyclists consumed 2000 mg taurine (double the amount in a can
of Red Bull) one hour before a 90 minute bike ride followed by
a time trial, the taurine offered no benefits compared to the
same bevereage without taurine.
Protein for building muscles
Some body builders wonder if a very high protein intake will
affect their long-term health. An 8-week study with strength
athletes who consumed 3 grams protein/kg (~1.5 grams pro/lb)
showed no signs of damage to liver and kidney function. This
equates to 210 grams of protein for a 154 pound athlete. That's
35 eggs!
Aging and exercise
* Without a doubt, exercise protects and improves our mental
function (to say nothing of our overall health). The question
arises: How long will it be before doctors routinely prescribe
exercise?
* In a study of seniors > 65 years old who completed a 20-week
exercise program, some of the subjects actually moved from the
category "demented" to "normal." Now that's incentive to keep
moving!
* While we assume that exercise is good for our health, we may
overlook the impact of injuries. A survey of 375 former
Division-1 athletes (of whom 41% had played football) indicates
36% of the former athletes vs 6% of non-athlete alums had
limitations in exercise due to old injuries. Exercise wisely!!
Sports dietitian Nancy Clark, MS RD counsels casual and
competitive athletes at her private practice at Healthworks,
the premier fitness center in Chestnut Hill MA (617-383-6100).
Her popular Sports Nutrition Guidebook ($23), Food Guide for
Marathoners: Tips for Everyday Champions ($20), and her
Cyclist's Food Guide: Fueling for the Distance ($20) are
available at www.nancyclarkrd.com or by sending a check to PO
Box 650124, W Newton MA 02465.