Key Points: A high carbohydrate + hydrogel sports drink did not improve performance in a study of elite XC skiers.
Have you been wondering whether using a hydrogel sports drink would improve your cross country skiing performance? In the past several years researchers have looked at the addition of alginate or pectin to sports drinks to increase available carbohydrate to support intense endurance activities. Alginate and pectin can form a gel when exposed to stomach acid, and theoretically can allow ingestion of high amounts of carbs with less gastrointestinal (GI) distress. At least one commercial sports drink (Maurten) has embraced this technology.
This is one area where there is actually an XC specific study! In 2019, Pettersson et al, of the University of Gothenburg in Sweden, looked at the effect of using a high carbohydrate (CHO) drink with added alginate and pectin (hydrogel) on performance in elite male and female biathletes and XC skiers. The 12 subjects completed 120 minutes of diagonal-style roller-skiing followed by a double poling time trial. Researchers looked at rates of burning CHO and fat, blood glucose and lactate levels, ratings of GI discomfort, and ratings of perceived exertion (RPE.) (RPE is the athlete’s rating of how much physical effort their performance required.)
Analysis of the results showed that using the high CHO + hydrogel vs. a placebo drink led to increased burning of carbohydrate from the drink and decreased burning of fat, while preserving muscle and liver glycogen. (This is consistent with studies of other athletes.) There were no differences between drinks in GI discomfort or RPE.
The authors conclude that the high CHO drink with hydrogel was well tolerated and might be helpful to meet CHO intake recommendations without a large fluid intake. Since the cold environment of skiing may mean lower sweat rates, this is a potential benefit. There was, however, no improvement in the time trial performance with use of the experimental beverage.
The bottom line is that you might find a hydrogel sports drink helpful to maintain your fueling, but there is no evidence that it will improve your performance.
© 2020 Kathleen Searles, MS, RDN, CSSD, LD
Reference: Pettersson S et al. Effects of supplementing with an 18%carbohydrate-hydrogel drink versus a placebo during whole-body exercise in -5°C with elite cross-country ski athletes: a crossover study. Journal of the International Society of Sports Nutrition. 2019, 16:46
Key Points: Sleep around 8 hours/night, eat vegetables, eat fish!
A study of Swedish elite adolescent athletes demonstrated decreased likelihood of injury in those with a healthy diet and adequate sleep. This interesting study highlights the importance of general health habits in keeping teen athletes on the snow.
The study subjects were 340 athletes attending National Sports High Schools. About 30% were snow sport athletes, including 72 cross-country skiers (39 men and 33 women), 12 downhill skiers (5 men and 7 women), 10 free-style skiers (8 men and 2 women), and 8 ski-orienteering athletes (4 men and 4 women.)
The athletes were surveyed in the autumn and again in the spring. Most athletes got enough sleep on the weekends, but 18.5% did not meet the sleep target of at least 8 hours/night during the week.
Diet shortfalls were in consumption of fruits and vegetables and fish. Almost 40% of athletes did not eat enough vegetables. (Nutrition intake was assessed by the Swedish Nutrition Food Agency index.)
This study was unique in looking at multiple variables that can affect risk of injury. Those athletes who slept more than 8 hours/day on weekdays AND met recommended nutrition intake had a significantly reduced risk of injury. (Injury was defined as physical complaints or pain resulting in decreased training volume, difficulty participating in normal training or competition, or reduced performance.)
How does this translate into every day practice? It looks like it is really important to be sure to get enough sleep! The National Sleep Foundation recommends 8-10 hours of sleep daily for teens aged 14-17. For those 18-25 years old the recommendation is 7-9 hours a day. Getting enough sleep may require careful organization to try to complete school assignments during the day where possible. For serious athletes sleep should be prioritized over social media time.
For the healthy eating piece, planning is helpful. Know when and how you will get your meals and snacks each day. Think about how to fit more vegetables into your usual meals. At breakfast sauté some spinach with your scrambled eggs or add a grilled tomato on the side. At lunch add some veggies to your sandwich – baby spinach, tomato slices, cucumber slices, lettuce, onions, and even shredded carrots are good on sandwiches. Choose vegetable side dishes like raw veggies, coleslaw, side salads, roasted veggies, or vegetable soup. At dinner be sure to include an ample portion of steamed veggies. For snacks try celery with peanut butter or raw veggies with hummus.
In this study a healthy diet also meant adequate fish consumption, and 43% of athletes did not meet the target. Fish is a great lean protein source and also supplies omega 3 fatty acids that play a role in reduced inflammation. Try a scoop of tuna on a salad or a tuna salad sandwich. Foil pouches of tuna are also convenient for snacks, and are tasty with some whole grain crackers like Triscuits. Grilled salmon or shrimp are popular dinner choices.
For help developing YOUR personalized nutrition plan, contact firstname.lastname@example.org.
Reference: von Rosen P, Frohm A, Kottorp a, Friden C, Hejne A. Too little sleep and an unhealthy diet could increase the risk of sustaining a new injury in adolescent elite athletes. Scand J Med Sci Sports 2016. doi: 10.1111/sms.12735
© 2019 Kathleen Searles, MS, RDN, CSSD, LD
Snow season is here and it's a great time to take a look at eating strategies to keep you on the slopes! Tendons (which attach muscle to bone) and ligaments (which attach bone to bone) are made of collagen. Foods that support collagen formation may be beneficial to strong joints, ligaments and tendons.
There are several nutrients that support collagen synthesis.
* Proline, hydroxyproline, lysine and hydroxylysine are amino acids, the building blocks of protein. Gelatin contains ample amounts of these particular amino acids.
* Vitamin C works with amino acids to create collagen. You can get plenty of Vitamin C from citrus fruits, melons, berries, kiwi, and dark green leafy vegetables.
*Flourine/fluoride is a mineral that supports tendons and ligaments. It is found in fluoridated water, tea, and fish.
* Copper is another mineral that may be helpful. Dark leafy greens, dried fruits (prunes), cocoa and black pepper contain copper.
Check out this information sheet from the National Athletic Trainers Association.
Try one or more of these tasty options to support your tendons and ligaments:
- include a bowl of orange and grapefruit sections with sliced kiwi
- try a strawberry or cantaloupe/blueberry smoothie and blend in some baby spinach leaves
- enjoy a cup of hot tea
- be sure to add some spinach or romaine to your sandwich
- try some jello with fruit as dessert
- add a cup of homemade broth made from bones
- add a salad of dark green leafy vegetables and citrus sections
- enjoy some fish seasoned liberally with pepper and lemon
© 2018 Kathleen Searles, MS, RDN, CSSD, LDN
Go Microgreen this winter!
My local co-op grocery store has been featuring microgreens from several local farmers this winter. They have made a delicious addition to our winter salads, sandwiches, omelets and frittatas. I especially like the mixes which contain spicy radish greens.
I first learned about microgreens at the farmer’s market in Gulf Shores, Alabama. Microgreens are plant seedlings that are harvested one to two weeks after germination. They have two cotyledon leaves, the leaves that first appear when a plant sprouts. They have a crispy texture and the flavor varies from mild to spicy depending on the type of seed.
The Alabama growers were excited to promote microgreens as nutritional powerhouses. It turns out that nutritional research supports this enthusiasm. Dr. Carolyn F. Weber, of Des Moines University, found that microgreens (in this study from broccoli) have more magnesium, manganese, copper, and zinc than mature vegetables. She said that you could eat about 40% less broccoli microgreens than broccoli florets for the same amount of nutrients.
The nutrient content of microgreens is influenced by how they are grown. Dr. Weber found that microgreens grown in compost were more nutritious than microgreens grown hydroponically. Being plants, microgreens are also sources of the polyphenolic compounds that act as anti-oxidants for our cells. Scientists are finding that the anti-oxidant concentration can be changed by manipulating the type and duration of light the seedlings receive.
Food scientists are very interested in microgreens because they can contribute a lot of nutrition without a lot of input. They require about half the water of a full grown vegetable, and do not need pesticides. There is even the possibility of growing microgreens in space to provide vital food sources of anti-oxidants for astronauts!
Microgreens can be a great addition for the winter sport athlete. The vitamins, minerals, and anti-oxidant compounds support your immune system and help combat inflammation. As noted above, I have used them on sandwiches (pictured below), on salads, and in egg dishes. Other suggestions include sprinkling onto a just baked pizza or a bowl of soup. They would also work well in smoothies.
Let me know how you use your microgreens on the Snowtrition Facebook group!
© 2018 Kathleen Searles, MS, RDN, CSSD, LD
Nutrition expert and snow enthusiast! Follow this blog for news and info to help move your skiing/boarding forward with good nutrition.
What Our Clients Are Saying
Kathy advised me in my role as Headmaster of Carrabassett Valley Academy, a high level competitive ski academy located at Sugarloaf, Maine. Kathy worked with the CVA coaching and kitchen staffs to help design a more nutritious menu for adolescent snow sport athletes. She very wisely directed how coaches could encourage good eating habits of athletes when traveling on the road. Kathy is always expanding her scope of service and is innovative in designing cutting-edge nutrition programs. – John Ritzo, Maine Ski Hall of Fame