Nutrition - Competing Interests

"What supplements should I consider taking for improving performance and staying healthy during competition season?"

This is a common question that I get from friends and fellow racers (running, nordic, skimo or otherwise - it doesn't matter). My answer is usually a rambling version of "it depends" as diet, training plan, and personal taste all bring a lot of variation. I started this article with the purpose of generally answering the question (and thats still how I will finish it) but quickly got sidetracked with the issue of competing interests.

Physiology - Lactate Threshold Testing

Many athletes and coaches use the term lactate threshold. Sometimes it is used in reference to a particular workout intensity and sometimes to testing but many times the meaning is unclear.

What is lactate and the lactate threshold?

We are able to live and exercise because our bodies are incredibly efficient at taking food and converting it into energy that we can use. Fat, carbohydrates, and protein are the three main types of nutrients that we can convert to energy.

Training - Periodization

This will be the first of a series of articles detailing some basic ideas on training methods and principles. Generally these are the concepts on which I have based my own training for skiing from high school, racing on an NCAA team, coaching other skiers, and competing in ski mountaineering races.

What is periodization and why have a plan?

Expedition - Nepal Update 2

Our second week in Nepal started on July 25th with a 6 hour drive to a small one hut village called Ramche. After Ramche, the road has been broken into small sections by several landslides so from here we had to hike the majority of the way.

Lining up to cross the landslide.

Physiology - Is hemoglobin concentration important to athletes?

I recently came across a paper published in the Middlebury Journal of Microbiology examining the relationship between hemoglobin concentration ([Hb]) and a variety of parameters including gender, living altitude, and cross country ski race performance^[1]. Unfortunately the paper appears to be primarily oriented toward validation of a new hemoglobin device, however it did get me to think about the importance of [Hb] in athletes and especially those training and competing at high-altitude.

Hemoglobin Molecule. Photo By Richard Wheeler (Zephyris) 2007. This file is licensed under the Creative Commons Attribution ShareAlike 3.0 License.

There are certain clear uses for [Hb] measurements, especially in athletes. Because hemoglobin is essential for oxygen transport to tissues in the blood, low concentrations of [Hb] can result in performance decrements. Anemia is a common blood disorder where the oxygen transport capacity of blood is reduced, either by low numbers of red blood cells or by low levels of hemoglobin (among a few others). The world health organization (WHO) has published normative values for [Hb] to be used for diagnosis of anemia^[2].

WHO low limits for [Hb] in diagnosis of Anemia.


Training at high altitude (above 2000 meters) has been repeatedly shown to increase total hemoglobin mass (tHb) though potentially only in athletes with an already low tHb^[3].  A study on the effect of an altitude training program conducted by the German Biathlon Team found significant increases in tHb as soon as the 4th day. These increases were the result of increased erythropoietin (EPO) production; a hormone that is responsible for creating new red blood cells. Total hemoglobin remained elevated through the 20th day of the study. Interestingly, 16-days after the team returned to sea-level, tHb returned to normal levels^[4].

High-altitude training in Colorado.


After a little bit of reading, this article led me to a few main thoughts and questions.

• [Hb] appears to be a useful hematological monitoring parameter. It is easily evaluated with a pinprick of blood on a Hemocue Device. Most athletes should have relatively constant [Hb] values and values below this constant could indicate anemia for example, while increased values could be indicative of successful altitude acclimatization or the use of performance enhancing techniques (blood doping).
• Hematological effects of altitude training begin to show within a few days of arrival and only last several weeks upon return to sea-level. This could be useful in the lead up to skimo races in Colorado next season.
• If altitude training only increases tHb in those with low sea-level values, is there a similar increase in performance?
• Could pre-screening athletes for [Hb] or tHb prior to altitude exposure predict performance ability at altitude.

Most of these questions are probably already answered in the literature but just require a little more hunting.


Works Cited:

1. Dodge, D. Using an EasyTouch® Hemoglobin Meter to Measure Hemoglobin Concentration in Elite Cross-Country Skiers. Middlebury Journal of Microbiology (2011).
2. Benoist, B. de et al. Worldwide prevalence of anaemia 1993-2005: WHO global database on anaemia. (World Health Organization: 2008).
3. Robach, P. & Lundby, C. Is live high-train low altitude training relevant for elite athletes with already high total hemoglobin mass? Scandinavian Journal of Medicine & Science in Sports 22, 303–305 (2012).
4. Heinicke, K., Heinicke, I., Schmidt, W. & Wolfarth, B. A three-week traditional altitude training increases hemoglobin mass and red cell volume in elite biathlon athletes. Int J Sports Med 26, 350–355 (2005).

Nutrition - Fuel Comparison

Without proper fuel, a ski tour can turn into a day of unnecessary suffering. My previous post covered some basic concepts for fueling. This post compares some of the different options for fast energy on the skin track.

See the full gallery on Posterous

Nick fueling up during a break from skiing pillow lines on the Duffy Lake Road. Sarah chowing down on crackers during a tour at Lake Louise.

Energy Gels:

GU

• Size: 32 grams (g)
• Cost: $1.95
• Calories: 100
• Total Carbs: 25g
• Sugar: 5g
• Electrolytes (Sodium & Potassium): 85mg
• Caloric Density: 3.125 kcal/g
• Cost per kcal: $0.0195

Hammer

• Size: 32.9g
• Cost: $1.66
• Calories: 80
• Total Carbs: 21g
• Sugar: 2g
• Electrolytes (Sodium & Potassium): 30mg
• Caloric Density: 2.432 kcal/g
• Cost per kcal: $0.0207

Cliff

• Size: 34g
• Cost: $1.20
• Calories: 100
• Total Carbs: 24g
• Sugar: 12g
• Electrolytes (Sodium & Potassium): 145mg
• Caloric Density: 2.941 kcal/g
• Cost per kcal: $0.012 

CarbBoom

• Size: 41 grams
• Cost: $1.10
• Calories: 110
• Total Carbs: 27g
• Sugar: 3g
• Electrolytes (Sodium & Potassium): 100mg
• Caloric Density: 2.683 kcal/g
• Cost per kcal: $0.01

GU comes in with the most calories but also at the second highest cost. All the gels use maltodextrin (a complex carbohydrate) as their primary ingredient. GU and Hammer contain a variety of amino acids. All four contain electolytes in varying amounts and each uses some type of preservative (Potassium Sorbate in GU, Hammer, CarbBoom. Potassium Citrate in Cliff). Cliff Gel is also advertised as certified organic.

Pre-event fuel is just as important. I will cover this in another post. (Sarah fueling up for a big day of skiing.)

As far as taste goes, I am happy with GU, Hammer and CarbBoom. Cliff leaves a little something to be desired but still no complaints. I am a big fan of the leash on the Cliff Gels that prevent you from losing the top after you have ripped it off - I wish GU would incorporate this feature into their gels.

Bonking can be a disaster. (Adam out of gas approaching the North Ridge of Mt. Baker.)

Solid Energy Blocks:

GU Chomps:

• Size: 60 grams
• Cost: $2.90
• Calories: 180
• Total Carbs: 46g
• Sugar: 22g
• Electrolytes (Sodium & Potassium): 180mg
• Caloric Density: 3.0 kcal/g
• Cost per kcal: $0.02

Cliff Bloks:

• Size: 60 grams
• Cost: $2.10
• Calories: 200
• Total Carbs: 48g
• Sugar: 24g
• Electrolytes (Sodium & Potassium): 180mg
• Caloric Density: 3.33 kcal/g
• Cost per kcal: $0.01

Honey Stinger:

• Size: 50 grams
• Cost: $2.10
• Calories: 160
• Total Carbs: 39g
• Sugar: 27g
• Electrolytes (Sodium & Potassium): 120mg
• Caloric Density: 3.2 kcal/g
• Cost per kcal: $0.01

Sharkies:

• Size: 45 grams
• Cost: $1.75
• Calories: 140
• Total Carbs: 36g
• Sugar: 17g
• Electrolytes (Sodium & Potassium): 140mg
• Caloric Density: 3.13 kcal/g
• Cost per kcal: $0.01

Here, things are a bit more equal. Cost is pretty much the same all around. Caloric density ranges but GU and Cliff contain the most calories per package which gives them a bit of an edge. Again, the ingredients are fairly similar. I think the Sharkies taste the most like candy. They also are the most chewy, something that I don't like when working hard. The GU Chomps are my favorite flavors and a good consistency. I would like to see leashes on these as well.

It's hard for gel to compete with summit Dunkaroos (Mt. Baker).

Final verdict: GU for the win in both categories but I think all the options are good fuel choices.

*Retail prices taken from MEC.com except Hammer Gel: (http://www.shophammernutrition.ca/hammer-gels/)