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Race Diet of Finishers and Non-Finishers in a 100 Mile (161 km) Mountain Footrace


Abstract and Figures

To determine if food and fluid intake is related to completion of a 161-km ultramarathon. Sixteen consenting runners in the Western States Endurance Run participated in the study. Race diets were analyzed using Nutritionist Pro software. Both total intake and intake by race segment (3 total) were evaluated. Six of 16 subjects completed the race (finishers) in 27.0 ± 2.3 hours (mean ± SD). Non-finishers completed 96.5 ± 20.5 km in 17.0 ± 3.9 h. Overall consumption rates of kilocalories, carbohydrate, fat, and sodium were significantly greater (P < 0.05) in finishers (4.6 ± 1.7 kcal/kg/h, 0.98 ± 0.43 g carbohydrate/kg/h, 0.06 ± 0.03 g fat/kg/h, 10.2 ± 6.0 mg sodium/kg/h) versus non-finishers (2.5 ± 1.3 kcal/kg/h, 0.56 ± 0.32 g carbohydrate/kg/h, 0.02 ± 0.02 g fat/kg/h, 5.2 ± 3.0 mg sodium/kg/h). Kilocalorie, fat, fluid, and sodium consumption rates during segment 1 (first 48 km) were significantly greater in finishers than in non-finishers. Completion of this 161-km race was related to greater fuel, fluid, and sodium consumption rates. However, intake ranges for the finishers were large, so factors other than race diet may have contributed to the successful completion of the race.
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Journal Title: Journal of the American College of
Volume: 30 Issue:
Month/Year: 2011Pages: 529-535
Article Author:
Article Title: Stuempfle; Race Diet of Finishers and Non-
Finishers in a 100 Mile Mountain Footrace
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Original Research
Race Diet of Finishers and Non-Finishers in a 100 Mile
(161 km) Mountain Footrace
Kristin J. Stuempfle, PhD, Martin D. Hoffman, MD, Louise B. Weschler, MAT, PT, Ian R. Rogers, MBBS, Tamara Hew-
Butler, DPM, PhD
Health Sciences Department, Gettysburg College, Gettysburg, Pennsylvania (K.J.S.), Department of Physical Medicine &
Rehabilitation, Department of Veterans Affairs, Northern California Health Care System, and University of California Davis Medical
Center, Sacramento, California (M.D.H.), Independent Researcher, Colts Neck, New Jersey (L.B.W.), Sir Charles Gairdner Hospital
and University of Western Australia, Perth, AUSTRALIA (I.R.R.), Exercise Science Program, Oakland University, Rochester,
Michigan (T.H.-B.)
Key words: ultrarunning, fuel consumption, hydration, sodium
Objective: To determine if food and fluid intake is related to completion of a 161-km ultramarathon.
Methods: Sixteen consenting runners in the Western States Endurance Run participated in the study. Race
diets were analyzed using Nutritionist Pro software. Both total intake and intake by race segment (3 total) were
Results: Six of 16 subjects completed the race (finishers) in 27.0 62.3 hours (mean 6SD). Non-finishers
completed 96.5 620.5 km in 17.0 63.9 h. Overall consumption rates of kilocalories, carbohydrate, fat, and
sodium were significantly greater (P,0.05) in finishers (4.6 61.7 kcal/kg/h, 0.98 60.43 g carbohydrate/kg/h,
0.06 60.03 g fat/kg/h, 10.2 66.0 mg sodium/kg/h) versus non-finishers (2.5 61.3 kcal/kg/h, 0.56 60.32 g
carbohydrate/kg/h, 0.02 60.02 g fat/kg/h, 5.2 63.0 mg sodium/kg/h). Kilocalorie, fat, fluid, and sodium
consumption rates during segment 1 (first 48 km) were significantly greater in finishers than in non-finishers.
Conclusions: Completion of this 161-km race was related to greater fuel, fluid, and sodium consumption
rates. However, intake ranges for the finishers were large, so factors other than race diet may have contributed to
the successful completion of the race.
Ultraendurance events (as exemplified by running events 50
km and longer) have risen in popularity in recent years [1,2].
These events include running races, cycling events, distance
swims, and triathlons. One of the most challenging ultra-
endurance events is the Western States Endurance Run
(WSER), a 100-mile (161-km) footrace. Large changes in
elevation and substantial variations in temperature characterize
the race. Over a 20-year period, finish rates at WSER have
ranged from 48%to 80%, and finish times have ranged from
approximately 15.5 hours to the usual time limit of 30 hours
[3]. Exercise of this duration in various environmental
conditions creates unique physiological challenges for runners,
including optimizing fuel, fluid, and electrolyte intake.
Total energy expenditure during the WSER has been
reported to range from approximately 13,000 to 16,000 kcal
[4,5]. Consumption of exogenous fuel will help offset this
energy expenditure and may contribute to a successful race.
Carbohydrate, fat, and protein all can be used to generate
energy during an ultraendurance run, with the relative
contribution of each dependent on existing energy stores,
exercise intensity, and duration, and composition of the race
diet [6]. Carbohydrates are commonly considered to be the
most important fuel during ultraendurance exercise, and since
glycogen stores are limited, it is important that athletes
consume carbohydrates during exercise to maintain blood
glucose levels [7,8]. Although carbohydrates are the preferred
fuel, fats also are a major energy substrate during ultra-
endurance exercise [6,9]. The role of protein metabolism
Address reprint requests to: Kristin J. Stuempfle, PhD, ATC, FACSM, Gettysburg College, Department of Health Sciences, Campus Box 432, 300 North Washington St,
Gettysburg, PA 17325. E-mail:
Journal of the American College of Nutrition, Vol. 30, No. 6, 529–535 (2011)
Published by the American College of Nutrition
during ultraendurance exercise is less clear, but proteins may
be an important substrate as well [6,9].
Maintaining fluid and electrolyte homeostasis is a challenge
for ultraendurance runners. The prevailing view is that
hypohydration (water deficit .2%–3%body mass loss) [10–
12] compromises performance and increases the risk of heat
illness [11,12], although this view has been challenged [12] and
;6%body mass loss has been observed among the fastest
runners in 161-km ultramarathons [13,14]. In contrast,
hyperhydration causes a reduction in blood sodium concentra-
tion, resulting in hyponatremia [15]. This potentially life-
threatening electrolyte disorder recently was documented in an
alarming 51%of finishers at the 2008 Rio Del Lago 100 Mile
Endurance Run [13] and 30%of finishers at the 2009 WSER
Food and fluid consumption is critical for successful
completion of a 161-km footrace. Yet very little research has
addressed the quantitative race diet needs of ultraendurance
runners. Therefore, the purpose of the present study was to
document food and fluid intake during a 161-km mountain
footrace and ascertain whether this intake is related to the
ability of runners to finish the race.
The study was set at the 2009 WSER in the Sierra Nevada
mountains of northern California. The 161-km point-to-point
race begins in Squaw Valley and ends in Auburn. The course is
primarily on single-track mountain trails with more than 5500
m of cumulative ascent and 7000 m of cumulative descent.
Nearby temperature during the race ranged from 48Cto378C.
Twenty-four aid stations on the course were stocked with
various foods, fluids, and electrolyte capsules.
Institutional Review Board approval was granted for this
study, and all subjects signed an informed consent document.
Subjects were recruited via e-mail prior to the race. Height was
measured during race registration several days before the race.
Weight was measured in the hour prior to race start, at 48 km,
at 100 km, and immediately postrace using a WW42D
impedance scale (Weight Watchers, New York, NY). Subjects
were wearing running shoes and running attire and were not
holding bottles or other items while being weighed. Body mass
index (BMI) was calculated from the measured height and
prerace body mass.
The subjects were not told what food, fluid, or electrolyte
capsules to consume during the race. A multipronged approach
with built-in redundancy maximized accurate accounting of
food, fluid, and electrolyte capsule intake:
1. Approximately 1 week prerace, subjects submitted via e-mail
a plan of the food, fluid, and electrolyte capsules they
intended to consume during the race. Subjects were
interviewed about their submitted plan during race registra-
tion to clarify any questions the investigators had about their
nutrition plan and to familiarize the subjects with the detail
that would be expected regarding brand, flavor, and amount
of each consumed item. Volumes of bottles and hydration
pack bladders were established.
2. At 48 km, 100 km, and immediately postrace, subjects were
interviewed (food, fluid, and electrolyte capsule intake;
presence of nausea and/or vomiting) and food wrappers were
3. Approximately 1 week postrace, the investigators sent the
subjects their race diet logs via e-mail so that the subjects
could review them for completeness and accuracy.
4. Brand, flavor, and amount of each item consumed were
Nutritionist Pro (Axxya Systems, Stafford, TX) software
was used to analyze the nutritional composition of the foods,
fluids, and electrolyte capsules consumed. Nutritional infor-
mation for items not included in Nutritionist Pro was obtained
from the manufacturer and added to the software database.
Diets were analyzed for kilocalories, macronutrients, and
Total intake for the race was determined, as well as intake/h
and intake/kg/h. Intake/kg/h was the focus of comparisons
between finishers and non-finishers since it normalized for
body mass and rate of intake. To evaluate changes in intake
over time, the data also were analyzed by race segment. The 3
segments were defined by the aid stations at 48 km and 100
km, where the subjects were weighed and interviewed and
divided the total race distance into approximate thirds.
Hereafter, these are referred to as segments 1, 2, and 3.
Unpaired ttests were used to evaluate differences between
finishers and non-finishers and between runners with nausea
and/or vomiting and runners without nausea and/or vomiting.
Prerace and postrace comparisons for finishers and non-
finishers were made using paired ttests. Repeated-measures
analysis of variance determined differences by segment for the
finishers, with follow-up Scheffe post hoc tests. Statistical
significance was set at P,0.05. Power was computed
retrospectively at 80%.
Six of 16 (38%; 4 male, 2 female) subjects completed the
race (finishers) in 27.0 62.3 h (mean 6SD). Non-finishers (10
out of 16; 62%; 8 male, 2 female) completed 96.5 620.5 km in
17.0 63.9 h (Table 1). Among the non-finishers, 10 runners
completed the first segment of the race, 6 completed the second
segment, and none completed the third race segment.
Retrospective power analysis suggested that these sample sizes
may have been insufficient to detect statistically significant
differences between the finishers and non-finishers. Overall
finish rate for the race was 60%. Finishers did not differ
530 VOL. 30, NO. 6
Ultramarathon Race Diet
significantly from non-finishers in age, years running, number
of ultra marathons completed, or number of 100-mile races
Finishers lost significant body mass prerace (68.8 615.8
kg) to postrace (66.7 615.4 kg; Table 2). Non-finishers lost
significant body mass prerace (74.3 613.2 kg) to the last
checkpoint before dropping out (72.0 612.1 kg). BMI, prerace
and postrace body mass, change in body mass, and rate of body
mass change did not differ significantly between finishers and
Subjects consumed a variety of ordinary foods (soups,
sandwiches, cookies, fruit, candy, potato chips, boiled potatoes,
etc.) and foods marketed specifically to exercising athletes
(energy bars, energy gels, etc.). They drank both water and
assorted sports drinks. Eighty-one percent of subjects (100%of
finishers, 70%of non-finishers) consumed electrolyte capsules.
Table 3 summarizes food intake during the race. Overall,
finishers consumed 8228 kcal during the race, consisting of
81.5%carbohydrate, 11.9%fat, and 6.6%protein, compared
with non-finishers who consumed 3106 kcal, consisting of
88.3%carbohydrate, 6.2%fat, and 5.4%protein. Rate of
caloric consumption was significantly greater in finishers (4.6
61.7 kcal/kg/h) compared with non-finishers (2.5 61.3 kcal/
kg/h). Finishers (0.98 60.43 g/kg/h) consumed carbohydrates
at a significantly greater rate compared with non-finishers (0.56
60.32 g/kg/h). Rate of fat consumption also was significantly
greater in finishers (0.06 60.03 g/kg/h) versus non-finishers
(0.02 60.02). Rate of protein consumption was similar in
finishers and non-finishers.
Food intake for each segment is summarized in Table 4.
During segment 1, finishers (4.3 61.6 kcal/kg/h) consumed
energy at a significantly higher rate compared with non-
finishers (2.7 61.2 kcal/kg/h). Rate of fat consumption also
was significantly greater during segment 1 in finishers (0.05 6
0.04) versus non-finishers (0.01 60.02). Comparing food
intake over segments in the finishers indicated the rate of
energy consumption in segment 3 (3.7 61.3 kcal/kg/h) was
significantly less than during segment 2 (6.1 62.8 kcal/kg/h).
Table 5 summarizes total fluid and sodium consumption,
and Table 6 presents this information by segment. Finishers
consumed a total of 19.8 L of fluid compared with non-
finishers who consumed 10.8 L. Overall fluid intake rate did
not differ significantly between finishers (11.0 64.3 ml/kg/h)
and non-finishers (8.6 63.1 ml/kg/h). During segment 1,
finishers (14.0 64.4 ml/kg/h) consumed fluid at a significantly
higher rate compared with non-finishers (9.2 62.7 ml fluid/kg/
h). Comparing fluid intake over segments in the finishers
indicated consumption rate in segment 3 (8.9 64.1 ml/kg/h)
was significantly less than during segment 1 (14.0 64.4 ml/kg/
Finishers consumed a total of 17.9 g of sodium compared
with non-finishers who consumed 6.2 g. Rate of sodium
consumption was greater in finishers (10.2 66.0 mg/kg/h)
compared with non-finishers (5.2 63.0 mg/kg/h). During
segment 1, finishers (9.3 66.0 mg/kg/h) consumed sodium at a
significantly greater rate compared with non-finishers (4.8 6
1.7 mg sodium/kg/h).
Seventy five percent of subjects (67%of finishers, 80%of
non-finishers) experienced nausea and/or vomiting. There were
no statistically significant differences in rate of food, fluid, or
sodium intake in runners with nausea and/or vomiting and
runners without nausea and/or vomiting.
On average, finishers in the present study consumed fuel at
a greater rate than non-finishers, and this difference was
apparent from race start. Overall rate of fluid consumption was
similar between finishers and non-finishers, but finishers
consumed fluid at a greater rater in the first segment of the
race. Finishers consumed sodium at a greater rate than non-
finishers, both overall and in the early part of the race. It is
important to note, however, that the ranges of fuel, fluid, and
sodium intake in finishers were large, consistent with factors
other than race contributing to successful completion of the
Energy expenditure during the WSER previously was
determined to be 13,000–16,000 kcal by indirect calorimetry
and doubly-labeled water [4,5]. The finishers in the current
Table 1. Demographic Comparison of Finishers and Non-
(n ¼6)
(n ¼10)
Age (y) 47.2 64.8 43.4 65.6
Years running 22.2 613.0 14.4 610.4
Previous ultramarathons
17.5 623.8 23.4 633.6
Distance completed during
race (km)
161.0 60.0 96.5 620.5
Running duration during race (h) 27.0 62.3 17.0 63.9
Data are presented as mean 6SD.
*P,0.05 between finishers and non-finishers.
Table 2. Body Mass Index (BMI) and Body Mass in Finishers
and Non-finishers
Variable Finishers (n ¼6) Non-finishers (n ¼10)
BMI 22.9 62.2 24.4 63.2
Start mass (kg) 68.8 615.8 74.3 613.2
End mass (kg) 66.7 615.4
72.0 612.1
DMass (kg) 2.0 61.2 2.4 61.5
%Mass D3.0 61.9 3.0 61.7
DMass (kg)/h 0.07 60.05 0.16 60.15
Data are presented as mean 6SD.
*P,0.05 prerace to postrace.
Ultramarathon Race Diet
study consumed only 8200 kcal, or 51%–63%of estimated
expenditure, so caloric needs were partially met from existing
carbohydrate and fat stores. Although it is difficult to establish
guidelines for caloric consumption per unit body mass per unit
time due to differences among events, environmental condi-
tions, and individuals, it has been suggested that ultraendurance
athletes should consume 4–6 kcal/kg/h for optimal performance
[6,16]. The energy consumption for the finishers (4.6 kcal/kg/h)
Table 3. Race Diet in Finishers and Non-finishers
Variable Finishers (n ¼6) Non-finishers (n ¼10)
Kcal 8228.3 62377.0 (5498.0–11,185.0) 3106.3 61545.3* (902.0–5057.0)
Kcal/h 308.2 699.8 (196.5–444.2) 185.2 691.3* (54.7–335.3)
Kcal/kg/h 4.6 61.7 (3.2–7.6) 2.5 61.3* (0.8–5.5)
%Carbohydrate 81.5 610.6 (71.1–98.4) 88.3 610.1 (71.3–100.0)
Carbohydrate (g) 1751.9 6658.2 (999.1–2367.0) 697.0 6394.4* (227.0–1257.0)
Carbohydrate (g/h) 65.8 627.0 (36.0–102.1) 41.5 623.2 (13.8–83.8 )
Carbohydrate (g/kg/h) 0.98 60.43 (0.58–1.70) 0.56 60.32* (0.19–1.25)
%Fat 11.9 68.0 (1.1–23.8) 6.2 66.2 (0.0–17.4)
Fat (g) 98.1 653.0 (11.7–148.3) 19.4 621.1* (0.0–68.7)
Fat (g/h) 3.6 61.9 (0.4–5.6) 1.3 61.4* (0.0–3.7)
Fat (g/kg/h) 0.06 60.03 (0.01–0.09) 0.02 60.02* (0.00–0.06)
%Protein 6.6 63.9 (0.1–11.1) 5.4 66.2 (0.0–21.4)
Protein (g) 131.2 679.0 (10.7–228.0) 43.0 656.7* (0.0–188.8)
Protein (g/h) 4.9 62.8 (0.4–8.0) 2.4 62.6 (0.0–8.6 )
Protein (g/kg/h) 0.08 60.05 (0.01–0.12) 0.04 60.04 (0.00–0.14)
Data are presented as mean 6SD (range).
*P,0.05 between finishers and non-finishers.
Table 4. Race Diet by Segment in Finishers and Non-finishers
Variable Finishers Non-finishers
Segment 1 4.3 61.6 (1.6–5.9) 2.7 61.2* (0.9–5.0)
Segment 2 6.1 62.8 (3.1–10.6) 3.3 62.3 (0.7–6.8)
Segment 3 3.7 61.3** (2.0–5.9)
Segment 1 84.8 611.3 (69.7–96.8) 91.9 68.9 (78.4–100.0)
Segment 2 81.2 612.7 (63.3–98.4) 82.3 616.1 (61.2–100.0)
Segment 3 81.5 614.7 (58.7–99.8)
Carbohydrate (g/kg/h)
Segment 1 0.9 60.4 (0.4–1.4) 0.6 60.3 (0.2–1.2)
Segment 2 1.3 60.7 (0.6–2.5) 0.7 60.6 (0.2–1.2)
Segment 3 0.8 60.3 (0.4–1.4)
Segment 1 10.6 68.5 (2.7–24.3) 4.0 66.1 (0.0–17.4)
Segment 2 12.0 610.6 (0.8–30.7) 9.0 69.5 (0.0–23.2)
Segment 3 11.3 69.3 (0.1–26.3) —-
Fat (g/kg/h)
Segment 1 0.05 60.04 (0.01–0.10) 0.01 60.02* (0.00–0.06)
Segment 2 0.07 60.05 (0.00–0.16) 0.03 60.03 (0.00–0.06)
Segment 3 0.05 60.05 (0.00–0.12)
Segment 1 4.6 63.9 (0.5–10.4) 4.1 66.3 (0.0–20.0)
Segment 2 6.8 64.0 (0.8–10.6) 8.7 68.5 (0.0–21.4)
Segment 3 7.2 66.1 (0.1–15.0)
Protein (g/kg/h)
Segment 1 0.05 60.06 (0.01–0.15) 0.02 60.04 (0.00–0.10)
Segment 2 0.10 60.07 (0.01–0.19) 0.07 60.06 (0.00–0.16)
Segment 3 0.07 60.06 (0.00–0.16)
Data are presented as mean 6SD (range).
*P,0.05 between finishers and non-finishers.
** P,0.05 between segment 2 and segment 3.
532 VOL. 30, NO. 6
Ultramarathon Race Diet
in this race fell within these guidelines, whereas the non-
finishers (2.5 kcal/kg/h) fell short. However, it should be noted
in Table 3 that the intake rate for the finishers ranged from 3.2–
7.6 kcal/kg/h, which is outside both the lower and upper ends
of the recommended range.
The average rate of fuel consumption of finishers in this
study (4.6 kcal/kg/h) is remarkably similar to that reported for
finishers of the Vermont 100 Mile Endurance Run (3.3 kcal/kg/
h and 4.0 kcal/kg/h), a comparable mountainous trail race
[17,18]. In contrast, a case study of a 161-km track run (7.8
kcal/kg/h) [19] and a 172-km treadmill run (3.1 kcal/kg/h) [20]
revealed both higher and lower fuel intake rates compared with
the finishers in the current study. It is evident that
ultramarathons can be finished through a large range of fuel
consumption rates.
Carbohydrates are considered to be the most important fuel
during ultraendurance exercise, and since glycogen stores are
limited to approximately 2000 kcal, it is essential that athletes
consume primarily carbohydrates in the race diet [7,8]. Both
finishers (81.5%carbohydrate, 11.9%fat, 6.6%protein) and
non-finishers (88.3%, 6.2%fat, 5.4%protein) in this study
consumed a carbohydrate-rich race diet. This race diet
composition is similar to previous reports for ultraendurance
runners [17,18,21]. It has been recommended that ultra-
endurance athletes consume 1.0–1.5 g/kg/h of carbohydrate
during exercise [6,8]. In this study, finishers (0.98 g/kg/h)
consumed carbohydrates at a significantly greater rate than
non-finishers (0.56 g/kg/h), and their consumption rate fell
approximately within these recommendations. However, the
range for finishers was large (0.58–1.7 g/kg/h), indicating that a
rate of carbohydrate consumption below the recommended
guidelines does not prevent race completion. The average rate
of carbohydrate intake for finishers in this study is quite similar
to the rate reported for the Vermont 100 Mile Endurance Run
(0.81 g/kg/h) [18].
Although carbohydrates are the preferred fuel during
ultraendurance exercise, fats also are a significant source of
energy [6,9]. In contrast to limited carbohydrate stores, adipose
tissue triglyceride theoretically provides sufficient energy for
about 5 days of continuous running [9]. Fat oxidation provides
a significant contribution to energy expenditure during low-
and moderate-intensity exercise and becomes increasingly
important as exercise duration increases [22]. In the present
study, the rate of fat consumption was significantly greater in
finishers (0.06 g/kg/h) versus non-finishers (0.02 g/kg/h). The
finishers’ fat consumption rate was similar to that previously
reported for finishers in the Vermont 100 Mile Endurance Run
(0.08 g/kg/h) [18].
The role of protein metabolism during ultraendurance
exercise is not clear [6,9]. However, as glycogen stores
become depleted during prolonged exercise, protein may
become an important fuel substrate [6,9]. In this race, the rate
of protein consumption did not differ between finishers and
non-finishers. The average rate of protein intake for finishers in
this study (0.08 g/kg/h) was very similar to the rate reported for
Table 5. Fluid and Sodium Consumption in Finishers and Non-finishers
Variable Finishers (n ¼6) Non-finishers (n ¼10)
Fluid (L) 19.8 66.8 (8.3–25.9) 10.8 65.2* (3.7–19.6)
Fluid (ml/h) 747.7 6282.9 (278.4–978.4) 620.5 6197.8 (222.3–858.7)
Fluid (ml/kg/h) 11.0 64.3 (6.1–16.3) 8.6 63.1 (3.0–12.9)
Sodium (g) 17.9 610.1 (8.3–35.7) 6.2 63.5* (2.7–13.5)
Sodium (mg/h) 671.1 6378.5 (313.9–1258.5) 370.3 6177.1* (163.5–617.5)
Sodium (mg/kg/h) 10.2 66.0 (4.4–17.7) 5.2 63.0* (2.2–10.6 )
Data are presented as mean 6SD (range).
*P,0.05 between finishers and non-finishers.
Table 6. Fluid and Sodium Consumption by Segment in Finishers and Non-finishers
Variable Finishers Non-finishers
ml fluid/kg/h
Segment 1 14.0 64.4 (8.2–17.7) 9.2 62.7* (4.7–13.0)
Segment 2 11.5 65.6 (4.8–17.2) 12.1 65.2 (5.7–19.3)
Segment 3 8.9 64.1** (4.1–14.0)
Sodium (mg/kg/h)
Segment 1 9.3 66.0 (4.2–19.4) 4.8 61.7* (3.0–7.9)
Segment 2 12.1 68.1 (3.9–24.8) 7.8 64.5 (2.8–13.8)
Segment 3 9.4 64.8 (4.0–15.1)
Data are presented as mean 6SD (range).
*P,0.05 between finishers and non-finishers.
** P,0.05 between segment 1 and segment 3.
Ultramarathon Race Diet
finishers of the Vermont 100 Mile Endurance Run (0.07 g/kg/
Maintaining fluid and electrolyte homeostasis during an
ultraendurance race is a challenge for athletes. These races
typically involve variations in temperature, elevation, wind,
and sun exposure. Hypohydration is the most common disorder
during ultraendurance events [6], but hyponatremia is among
the most serious [15]. Hyponatremia primarily results from
hyperhydration, which can be caused by the overconsumption
of fluids and/or the inappropriate release of arginine vasopres-
sin [15]. The potential contribution of sodium loss to the
development of hyponatremia has yet to be demonstrated [15].
It is difficult to establish universal guidelines for fluid and
electrolyte replacement during ultraendurance exercise because
sweat rates and sweat composition vary greatly among
individuals and depend on environmental conditions, exercise
intensity and duration, level of acclimatization, diet, and
genetic predisposition [11]. For instance, sweat rates have been
reported to vary from 0.5 to 2.0 L/h [11], and sweat sodium
concentration averages ;35 mEq/L with a range of 10–70
mEq/L [23]. Current fluid replacement recommendations from
the International Marathon Medical Directors Association are
to drink to thirst (ab libitum), because drinking to thirst will
protect athletes from the hazards of both hypohydration and
hyperhydration by providing real-time feedback on plasma
osmolality [24]. However, the marketing of sports drinks
continues to promote overdrinking [25]. A recent study [26] of
runners in 5- to 21-km races indicated that 56%drink only
when thirsty. However, 37%drink according to a preset
schedule, and 9%drink as much as possible during a race. Both
of the latter groups are at risk for hyperhydration and the
development of hyponatremia. It has been recommended that
ultraendurance athletes consume 1 g sodium/h [6,8].
It has been suggested that athletes who gain body mass
during endurance exercise are overhydrated, those with body
mass loss 3%are euhydrated, and those with body mass loss
.3%are dehydrated [10]. In the present study, both finishers
(2.0 61.2 kg) and non-finishers (2.4 61.5 kg) lost
significant body mass prerace to postrace. The average
percentage body mass change for both groups was 3.0%,
suggesting that these runners were essentially euhydrated and
had maintained fluid homeostasis [10]. The overall rate of fluid
consumption was similar between the finishers and the non-
finishers, and the average rate of fluid consumption for the
finishers (11.0 ml/kg/h) was comparable to the rate reported for
the Vermont 100 Mile Endurance Run (9.8 ml/kg/h [17] and
11.1 ml/kg/h [18]). As was the case with fuel consumption, the
range of fluid intake rates among the finishers of the current
race was large (6.1–16.3 ml/kg/h).
Electrolyte capsules were available at aid stations in the
current study, and their consumption was widespread. Eighty-
one percent of subjects (100%of finishers, 70%of non-
finishers) consumed electrolyte capsules as part of their race
diet. Overall rate of sodium consumption was significantly
greater in finishers (10.2 66.0 mg/kg/h) compared with non-
finishers (5.2 63.0 mg/kg/h). It is not known if this greater rate
of sodium consumption in finishers was secondary to the
greater fuel consumption rate, increased use of electrolyte
capsules, and/or increased sodium palatability. Rate of sodium
consumption for the finishers was lower than the recommended
1 g sodium/h [6,8] but was similar to the rate reported for
Vermont 100 Mile Endurance Run finishers (9.4 mg/kg/h).
Similar to fuel and fluid consumption, finishers in the current
study had a large range of sodium intakes (4.4–17.7 mg/kg/h).
The role of sodium supplementation during ultraendurance
exercise warrants further investigation.
In addition to examining overall rates of fuel, fluid, and
sodium consumption, we also investigated intake rates by race
segment. Segment 1 (0–48 km) was at the highest altitude and
was completed under relatively cool conditions. Segment 2
(48–100 km) was regarded as the most difficult part of the
course because of the greatest altitude changes and the hottest
temperatures. Segment 3 (100–161 km) was at the lowest
altitude and was generally completed under cooler and dark
conditions. During segment 1, finishers consumed fuel, fluid,
and sodium at significantly greater rates than non-finishers did
(Tables 4 and 6 ). The rate of fuel and fluid consumption
decreased significantly for finishers during the third segment
compared with earlier segments (Tables 4 and 6). This may
have been the result of physical fatigue, sleep deprivation,
flavor fatigue, gastrointestinal distress [16], or the difficulty of
completing this segment in the dark [27].
Nausea and/or vomiting are common challenges for ultra-
endurance runners [16]. A previous study at WSER [28]
revealed that 37%of finishers and 40%of non-finishers
experienced nausea and/or vomiting, and among the non-
finishers, this was the most common reason for dropping out of
the race. In the present study, 75%of subjects (67%of
finishers, 80%of non-finishers) experienced nausea and/or
vomiting. There were no statistically significant differences in
rate of food, fluid, or sodium intake between these cohorts,
suggesting that factors other than race diet contributed to the
onset of nausea and/or vomiting.
Completion of this 161-km trail race was associated with
greater fuel, fluid, and sodium consumption rates. In addition,
average intake rates were greater among finishers in the first
segment of the race. However, it should be noted that intake
ranges for fuel, fluid, and sodium consumption were large.
Some runners with relatively low intake rates finished, while
others with relatively high intake rates did not finish. Factors
beyond those examined in this study may have contributed to
successful completion of the race.
534 VOL. 30, NO. 6
Ultramarathon Race Diet
The authors thank Ginger Hook, Dr. Kevin Fogard,
Benjamin Holexa, and Bill Butler for their crucial help in the
field. The study was supported by the Western States
Endurance Run Foundation.
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Received December 16, 2010; revision accepted July 18, 2011.
Ultramarathon Race Diet
... The attainment of such an objective may be made more difficult by the in-race repetitive mechanical disruption to the gut, inducing gastrointestinal symptoms (GIS) [4,5], which also may be amplified by such significant intake [6]. Observational studies have reported actual intake to be lower than that advised [7][8][9][10], lower for nonfinishers than finishers [4], and lower for slower than faster runners [7]. ...
... The attainment of such an objective may be made more difficult by the in-race repetitive mechanical disruption to the gut, inducing gastrointestinal symptoms (GIS) [4,5], which also may be amplified by such significant intake [6]. Observational studies have reported actual intake to be lower than that advised [7][8][9][10], lower for nonfinishers than finishers [4], and lower for slower than faster runners [7]. These results not only highlight the overall difficulty of ultramarathoners to follow the recommendations but also underline the apparent ability of elite athletes to adopt a race diet closer to recommendations, likely through a more adequate nutritional program and/or one that results in improved gut tolerance [11,12]. ...
... Solid Food Caloric Fluids Fruits [10] Biscuit [1] Soda [9] Cereal bar [7] Chocolate [1] High-CHO sport drink [5] Protein bar [5] Potato [1] Chicken broth [5] Cold meat [3] Marzipan [1] Fruit juice [5] Sweet potatoes [3] Rice [1] High-PRO sport drink [2] Cheese [3] Bread [1] Energy drink [1] Nuts [3] Cheese sandwich [1] Rice pudding [2] Soft Food Non caloric fluids Cracker [2] Stewed apples [8] Water [11] Fruit bar [2] Mashed potatoes [4] Sparkling water [8] Gingerbread [2] Energy gel [4] Coffee [6] Cake [2] High-protein cream [2] Tea [1] Savory cake [1] Honey [1] The number of participants having consumed an item is indicated in brackets the possibility to resupply. Their "relative intake" was calculated by dividing their absolute intake by the number of laps per hour to also take into account the very likely decrease in the frequency of the possibility to feed and/or drink. ...
Full-text available
Background: A food and fluid intake program is essential for ultraendurance athletes to maximize performance and avoid possible gastrointestinal symptoms (GIS). However, the ability to follow such a program during a race has been under-assessed. We thus investigated the fluctuations of food and fluid intake during the 24-h run World Championship of 12 elite athletes (6 men and 6 women; age: 46 ± 7 years, height: 170 ± 9 cm, weight: 61.1 ± 9.6 kg, total distance run: 193-272 km) and assessed their ability to follow their nutritional program. Methods: Real-time overall intake (fluids, energy, and macronutrients) was recorded and compared to that of their program. The temporal difference in absolute values and the degree of divergence from their program were assessed, divided into four 6-h periods. GIS were recorded during the race. A questionnaire identifying the details of their nutritional program and the self-assessed causes of their inability to follow it was completed by the participants the day after the race. Results: Water, total fluid, carbohydrates (CHO), and energy intake decreased during the last quarter of the 24-h ultramarathon relative to the first half (p = 0.024, 0.022, 0.009, and 0.042). However, the differences were no longer significant after these values were normalized by the number of passages in front of the supply tent. The participants progressively failed to follow their nutritional program, with the intake of their planned items dropping to approximately 50% during the last quarter. However, this was adequately compensated by increases in unplanned foods allowing them to match their expected targets. GIS, lack of appeal of the planned items, and attractivity of unplanned items were the main explanations given for their deviation from the program (64, 27, and 27%, respectively). Conclusion: Despite evident difficulty in following their nutritional programs (mostly attributed to GIS), elite ultraendurance runners managed to maintain high rates of fluid and food intake during a 24-h ultramarathon and therefore still met their planned elevated nutritional objectives.Abbreviations: CHO: carbohydrates, GIS: gastrointestinal symptoms.
... Studies investigating CHO intake of ultra-runners during competition have shown large variations in intake (25-71 g·h. −1 ), at elite and non-elite levels (Glace et al., 2002;Moran et al., 2011;Stuempfle et al., 2011;Costa et al., 2014;Wardenaar et al., 2015;Stellingwerff, 2016;Martinez et al., 2018;Lavoué et al., 2020). Faster/elite runners have been shown to consume more hourly CHO than slower/amateur runners (Stellingwerff, 2016), and finishers reported to consume more than non-finishers (Stuempfle et al., 2011). ...
... −1 ), at elite and non-elite levels (Glace et al., 2002;Moran et al., 2011;Stuempfle et al., 2011;Costa et al., 2014;Wardenaar et al., 2015;Stellingwerff, 2016;Martinez et al., 2018;Lavoué et al., 2020). Faster/elite runners have been shown to consume more hourly CHO than slower/amateur runners (Stellingwerff, 2016), and finishers reported to consume more than non-finishers (Stuempfle et al., 2011). From these studies, a higher CHO intake is associated with improved performance, but ultrarunners typically consume lower amounts than recommended, and less than competitors in other ultra-endurance disciplines (Pfeiffer et al., 2012). ...
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Carbohydrate (CHO) intake recommendations for events lasting longer than 3h indicate that athletes should ingest up to 90g.h. ⁻¹ of multiple transportable carbohydrates (MTC). We examined the dietary intake of amateur (males: n =11, females: n =7) ultra-endurance runners (mean age and mass 41.5±5.1years and 75.8±11.7kg) prior to, and during a 24-h ultra-endurance event. Heart rate and interstitial glucose concentration (indwelling sensor) were also tracked throughout the event. Pre-race diet (each 24 over 48h) was recorded via weighed intake and included the pre-race meal (1–4h pre-race). In-race diet (24h event) was recorded continuously, in-field, by the research team. Analysis revealed that runners did not meet the majority of CHO intake recommendations. CHO intake over 24–48h pre-race was lower than recommended (4.0±1.4g·kg ⁻¹ ; 42±9% of total energy), although pre-race meal CHO intake was within recommended levels (1.5±0.7g·kg ⁻¹ ). In-race CHO intake was only in the 30–60g·h ⁻¹ range (mean intake 33±12g·h ⁻¹ ) with suboptimal amounts of multiple transportable CHO consumed. Exercise intensity was low to moderate (mean 68%HR max 45%VO 2max ) meaning that there would still be an absolute requirement for CHO to perform optimally in this ultra-event. Indeed, strong to moderate positive correlations were observed between distance covered and both CHO and energy intake in each of the three diet periods studied. Independent t -tests showed significantly different distances achieved by runners consuming ≥5 vs. <5g·kg ⁻¹ CHO in pre-race diet [98.5±18.7miles (158.5±30.1km) vs. 78.0±13.5miles (125.5±21.7km), p =0.04] and ≥40 vs. <40g·h ⁻¹ CHO in-race [92.2±13.9miles (148.4±22.4km) vs. 74.7±13.5miles (120.2±21.7km), p =0.02]. Pre-race CHO intake was positively associated with ultra-running experience, but no association was found between ultra-running experience and race distance. No association was observed between mean interstitial glucose and dietary intake, or with race distance. Further research should explore approaches to meeting pre-race dietary CHO intake as well as investigating strategies to boost in-race intake of multiple transportable CHO sources. In 24-h ultra-runners, studies examining the performance enhancing benefits of getting closer to meeting pre-race and in-race carbohydrate recommendations are required.
... Furthermore, these recent developments do not appear to dissuade runners from participation in these events with 74% of runners indicating that they would continue to train and participate in ultramarathon events even if they were to learn, with absolute certainty, that it was bad for their health [28]. While research regarding inflammation [2,35], cardiac function [27,38,51], and nutrition practices [66,67,74] have been well-reviewed in this population, the physiological effects of prolonged exercise on the peripheral vascular system, neuromuscular function, and running mechanics are less well documented. A comprehensive understanding of theses physiological impacts of ultramarathon participation is critical to provide appropriate training and recovery guidelines for these athletes. ...
... Thirdly, nutrition and hydration practices become exponentially more involved in ultramarathon race distances. Adequate total kilocalorie, carbohydrate and water and sodium intake are large determinants of 100 miles race completion [67]. However, these requirements are often not achieved [74] leaving finishers dehydrated and in a caloric deficit. ...
Full-text available
Participation in ultramarathon events has grown substantially in the past decade. However, poor understanding of the physiological outcomes associated with participation in this sport prevents athletes and clinicians from adequately addressing performance and recovery tactics. The purpose of this review was to summarize developments in the literature in the last 10 years regarding acute and chronic responses to ultramarathon running with a focus on the peripheral vascular system, neuromuscular outcomes, and running mechanics. Evidence suggests that there are acute impairments in large artery compliance especially following the longer ultramarathon distances. However, most literature indicates that chronic vascular impairments are not evident in ultramarathon runners. Both central and peripheral fatigue mechanisms contribute to declines in muscle force production that may last up to several weeks in some muscles following an ultramarathon. Alterations in gait kinematics and skeletal muscle oxidative capacity increase the metabolic cost of running over prolonged running distances (> 4 h). Several factors such as elevation changes and nutritional practices make interpretation of findings challenging. Future studies are needed to better understand the interplay among systems and how external factors contribute to these outcomes to optimize performance and inform recovery strategies in this increasingly popular sport.
... Between 30% and 90% of these athletes have experienced some types of GI problem while competing [6,8,20,32,35,36]. While the causes of GI symptoms during prolonged exercise are multifactorial [32,37,38], CHO contained in foods and beverages could intensify these situations [39], and so GI problems could be another reason why SOUT athletes do not adhere to nutritional recommendations [5,6,8,32,35,38,40,41]. However, GI problems caused by CHO intake could be reduced by intestinal training and suitable hydration and nutrition strategy [8,42]. ...
... Possibly, this study associates high intake with lower GI symptoms, given that athletes who practice sport daily with a suitably usual intake assume that high CHO intake is part of such daily practice. Moreover, a greater intake of fluids and foods helps to maintain better hydration status and, therefore, limits GI problems [41]. Symptoms are considered more likely with high fiber intake, fats and highly concentrated CHO solutions (i.e., hypertonic drinks) [92], while hypertonic solutions encourage net water secretion into the intestinal lumen, resulting in a temporary net loss of water from the body [93]. ...
Full-text available
Due to the high metabolic and physical demands in single-stage one-day ultra-trail (SOUT) races, athletes should be properly prepared in both physical and nutritional aspects in order to delay fatigue and avoid associated difficulties. However, high carbohydrate (CHO) intake would seem to increase gastrointestinal (GI) problems. The main purpose of this systematic review was to evaluate CHO intake during SOUT events as well as its relationship with fatigue (in terms of internal exercise load, exercise-induced muscle damage (EIMD) and post-exercise recovery) and GI problems. A structured search was carried out in accordance with PRISMA guidelines in the following: Web of Science, Cochrane Library and Scopus databases up to 16 March 2021. After conducting the search and applying the inclusion/exclusion criteria, eight articles in total were included in this systematic review, in all of which CHO intake involved gels, energy bars and sports drinks. Two studies associated higher CHO consumption (120 g/h) with an improvement in internal exercise load. Likewise, these studies observed that SOUT runners whose intake was 120 g/h could benefit by limiting the EIMD observed by CK (creatine kinase), LDH (lactate dehydrogenase) and GOT (aspartate aminotransferase), and also improve recovery of high intensity running capacity 24 h after a trail marathon. In six studies, athletes had GI symptoms between 65–82%. In summary, most of the runners did not meet CHO intake standard recommendations for SOUT events (90 g/h), while athletes who consumed more CHO experienced a reduction in internal exercise load, limited EIMD and improvement in post-exercise recovery. Conversely, the GI symptoms were recurrent in SOUT athletes depending on altitude, environmental conditions and running speed. Therefore, a high CHO intake during SOUT events is important to delay fatigue and avoid GI complications, and to ensure high intake, it is necessary to implement intestinal training protocols.
... Success in ultramarathons is generally associated with greater CHO consumption [3,4,6,14]. Adequate CHO intake allows glycogen to be spared and mitigates muscle damage. ...
Full-text available
Background: The present case study examined the relationship between 24 h ultramarathon performance and the "big three" strategies of training, nutrition, and pacing. Methods: A 32-year-old male ultramarathon runner (body mass: 68.5 kg, height: 179 cm) participated in a 24 h ultramarathon race. Training status was quantified based on from a GPS sports watch. The nutritional status was evaluated during the week leading up to the race, and blood glucose level and heart rate were measured during the race. Results: His aim of the distance was 200 km, but the actual performance was 171.760 km. The blood glucose level was stable because of adequate CHO intake before (7.2 ± 0.8 g/kg/day) and during the race (48 g/h). The running speed decreased in the middle and later stages of the race despite adequate CHO intake and a lack of high intensity running in the early stage of the race. The longest training session before the race (80 km) had to be significantly shorter compared to the aim. Conclusions: For optimal 24 h ultramarathon performance, the "big three" strategies of training, nutrition, and pacing are all important. However, the performance level estimated based on previous studies may be achievable even with insufficient training, as long as the nutritional and pacing strategies are appropriate.
... Les athlètes ont de la difficulté à consommer suffisamment de calories pour compenser l'énorme dépense énergétique lors d'un ultramarathon ; aussi, un déficit énergétique est présent dans la majorité des cas. Les apports énergétiques lors d'une course en sentier (« ultra-trail »), variables selon la tolérance digestive et l'appétit de l'athlète, représentent entre 24 et 63 % des dépenses énergétiques (8). Aussi, la capacité de l'athlète à ingérer le plus d'énergie possible durant l'ultramarathon devient l'enjeu primordial de sa performance. ...
... Indeed, as running distance increases from middle-distance to long-distance races the impact of aerobic adaptations on running performance has been found to become increasingly important (Hill, 1999;Gastin, 2001;Duffield et al., 2005). However, performance in ultramarathon races has been demonstrated to be particularly influenced in a critical manner by strategies applied during the race about food, fluid and sodium intake (Stuempfle et al., 2011;Martinez et al., 2018). Thus, marathon race may represent the ideal model for the investigation of the role of endurance exercise adaptations in the determination of running performance in long-distance races. ...
Full-text available
Aim We aimed to investigate the main anthropometric, cardiorespiratory and haematological factors that can determine marathon race performance in marathon runners. Methods Forty-five marathon runners (36 males, age: 42 ± 10 years) were examined during the training period for a marathon race. Assessment of training characteristics, anthropometric measurements, including height, body weight ( n = 45) and body fat percentage (BF%) ( n = 33), echocardiographic study ( n = 45), cardiopulmonary exercise testing using treadmill ergometer ( n = 33) and blood test ( n = 24) were performed. We evaluated the relationships of these measurements with the personal best marathon race time (MRT) within a time frame of one year before or after the evaluation of each athlete. Results The training age regarding long-distance running was 9 ± 7 years. Training volume was 70 (50–175) km/week. MRT was 4:02:53 ± 00:50:20 h. The MRT was positively associated with BF% ( r = 0.587, p = 0.001). Among echocardiographic parameters, MRT correlated negatively with right ventricular end-diastolic area (RVEDA) ( r = −0.716, p < 0.001). RVEDA was the only independent echocardiographic predictor of MRT. With regard to respiratory parameters, MRT correlated negatively with maximum minute ventilation indexed to body surface area (VEmax/BSA) ( r = −0.509, p = 0.003). Among parameters of blood test, MRT correlated negatively with haemoglobin concentration ( r = −0.471, p = 0.027) and estimated haemoglobin mass (Hbmass) ( r = −0.680, p = 0.002). After performing multivariate linear regression analysis with MRT as dependent variable and BF% (standardised β = 0.501, p = 0.021), RVEDA (standardised β = −0.633, p = 0.003), VEmax/BSA (standardised β = 0.266, p = 0.303) and Hbmass (standardised β = −0.308, p = 0.066) as independent variables, only BF% and RVEDA were significant independent predictors of MRT (adjusted R ² = 0.796, p < 0.001 for the model). Conclusions The main physiological determinants of better marathon performance appear to be low BF% and RV enlargement. Upregulation of both maximum minute ventilation during exercise and haemoglobin mass may have a weaker effect to enhance marathon performance. Clinical Trial Registration , identifier NCT04738877.
The aim of this study was to examine the effects of the menstrual cycle on vertical jumping, sprint performance and force-velocity profiling in resistance-trained women. A group of resistancetrained eumenorrheic women (n = 9) were tested in three phases over the menstrual cycle: bleeding phase, follicular phase, and luteal phase (i.e., days 1–3, 7–10, and 19–21 of the cycle, respectively). Each testing phase consisted of a battery of jumping tests (i.e., squat jump [SJ], countermovement jump [CMJ], drop jump from a 30 cm box [DJ30], and the reactive strength index) and 30 m sprint running test. Two different applications for smartphone (My Jump 2 and My Sprint) were used to record the jumping and sprinting trials, respectively, at high speed (240 fps). The repeated measures ANOVA reported no significant differences (p � 0.05, ES < 0.25) in CMJ, DJ30, reactive strength index and sprint times between the different phases of the menstrual cycle. A greater SJ height performance was observed during the follicular phase compared to the bleeding phase (p = 0.033, ES = −0.22). No differences (p � 0.05, ES < 0.45) were found in the CMJ and sprint force-velocity profile over the different phases of the menstrual cycle. Vertical jump, sprint performance and the force-velocity profiling remain constant in trained women, regardless of the phase of the menstrual cycle.
Objective: Exercise-associated Muscle Cramp (EAMC) is an intense, painful, and involuntary contraction of skeletal muscles during a physical activity. Runners are more prone to this syndrome than other athletes. The present paper aims to review of the literature on EAMC in runners to determine the reasons and nature of EAMC in this sports field. Methods: A search was conducted for related studies from 1997 to 2021 in MEDLINE/PubMed, EMBASE/SCOPUS, LILACS, CINAHL, CENTRAL, Web of Science, PEDro, Google Scholar as well as MagIran, IranDoc, IranMedex, MedLib using MeSH Keywords. The reference section of the studies were also checked to find more studies. Finally, 15 eligible papers on EAMC in runners were reviewed and findings were reported. Results: Several factors were found to be effective in EAMC among runners, including dehydration, electrolyte deficit, cold, long training or competition period, increased body temperature during training or competition, history of injury or muscle cramp, increased training intensity in short time, and dietary restrictions. Conclusion: The cause of EAMC in runners seems to be multifactorial.
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Overdrinking and non-osmotic arginine vasopressin release are the main risk factors for exercise-associated hyponatremia (EAH) in ultra-marathon events. However, particularly during ultra-marathon running in mountainous regions, eccentric exercise and hypoxia, which have been shown to modulate inflammation, hormones regulating fluid homeostasis (hypoxia), and oxidative stress, could contribute to serum sodium changes in a dose-dependent manner. To the best of our knowledge, the contribution of these factors, the extent of which depends on the duration and geographical location of the race, has not been well studied. Twelve male participants (11 finishers) of the short (69km, 4,260m elevation-gain) and 15 male participants (seven finishers) of the long (121km, 7,554m elevation-gain) single-stage Südtirol Ultra Sky-Race took part in this observational field study. Venous blood was drawn immediately before and after the race. Analyses included serum sodium concentration, copeptin (a stable marker for vasopressin), markers of inflammation, muscle damage and oxidative stress. Heart rate was measured during the race and race time was obtained from the race office. During the short and the long competition two and one finishers, respectively showed serum sodium concentrations >145mmol/L. During the long competition, one athlete showed serum sodium concentrations <135mmol/L. Only during the short competition percent changes in serum sodium concentrations of the finishers were related to percent changes in body mass ( r =−0.812, p =0.002), total time ( r =−0.608, p =0.047) and training impulse (TRIMP) ( r =−0.653, p =0.030). Data show a curvilinear (quadratic) relationship between percent changes in serum sodium concentration and body mass with race time when including all runners (short, long, finishers and non-finishers). The observed prevalence of hypo- and hypernatremia is comparable to literature reports, as is the relationship between serum sodium changes and race time, race intensity and body mass changes of the finishers of the short race. The curvilinear relationship indicates that there might be a turning point of changes in serum sodium and body mass changes after a race time of approximately 20h. Since the turning point is represented mainly by non-finishers, regardless of race duration slight decrease in body mass and a slight increase in serum sodium concentration should be targeted to complete the race. Drinking to the dictate of thirst seems an adequate approach to achieve this goal.
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The purpose was to determine the energy expenditure during ultradistance trail running. A portable metabolic unit was carried by a male subject for the first 64.5 km portion of the Western States 100 running race. Calibrations were done with known gases and volumes at ambient temperature, humidity and pressure (23-40.5 °C and 16-40% respectively). Altitude averaged 1692.8 ± 210 m during data collection. The male subject (36 yrs, 75 kg, VO2max of 67.0 ml·kg(-1)·min(-1)) had an average (mean ± SD) heart rate of 132 ± 9 bpm, oxygen consumption of 34.0 ± 6.8 ml·kg(-1)·min(-1), RER of 0.91 ± 0.04, and VE of 86.0 ± 14.3 L·min(-1) during the 21.7 km measuring period. This represented an average of 51% VO2max and 75% heart rate maximum. Energy expenditure was 12.6 ± 2.5 kcals·min(-1), or 82.7 ± 16.6 kcals·km(-1) (134 ± 27 kcals·mile(-1)) at 68.3 ± 12.5% carbohydrate. Extrapolation of this data would result in an energy expenditure of >13,000 kcals for the 160 km race, and an exogenous carbohydrate requirement of >250 kcal·hr(-1). The energy cost of running for this subject on separate, noncompetitive occasions ranged from 64.9 ± 8.5 to 74.4 ± 5.5 kcals·km(-1) (105 ± 14 to 120 ± 9 kcals·mile(-1)). Ultradistance trail running increases energy expenditure above that of running on nonundulating terrain, which may result in underestimating energy requirements during these events and subsequent undernourishment and suboptimal performance. Key PointsThe energy cost of running is elevated during ultradistance trail races compared to normal running conditions.This elevated energy cost results in a ~12% increase in energy expenditure for a given distance.Ad libitum energy intake may grossly underestimate the demand of ultradistance running in the conditions investigated in this paper, thus jeopardizing race performance.
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Despite increased 161-km ultramarathon participation in recent years, little is known about those who pursue such an activity. This study surveyed entrants in two of the largest 161-km trail ultramarathon runs in North America to explore demographic characteristics and issues that affected race performance. All entries of the 2009 Western States Endurance Run and the Vermont 100 Endurance Race were invited to complete a postrace questionnaire. There were 500 respondents among the 701 race entries (71.3% response). Finish time was found to have a significant (P ≤ .01) negative association with training volume and was generally directly associated with body mass index. Among nonfinishers, the primary reason for dropping out was nausea and/or vomiting (23.0%). Finishers compared with nonfinishers were more likely (P ≤ .02) to report blisters (40.1% vs 17.3%), muscle pain (36.5% vs 20.1%), and exhaustion (23.1% vs 13.7%) as adversely affecting race performance, but nausea and/or vomiting was similar between groups (36.8% vs 39.6%). Nausea and/or vomiting was no more common among those using nonsteroidal anti-inflammatory drugs (NSAIDs), those participating in the event with higher ambient temperatures, those with a lower training volume, or those with less experience at finishing 161-km races. Overall use of NSAIDs was high, and greater (P = .006) among finishers (60.5%) than nonfinishers (46.4%). From this study, we conclude that primary performance-limiting issues in 161-km ultramarathons include nausea and/or vomiting, blisters, and muscle pain, and there is a disturbingly high use of NSAIDs in these events.
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Exercise-associated hyponatraemia (EAH) is a dilutional hyponatraemia that is caused primarily by the intake of hypotonic fluid beyond the dictates of thirst and exacerbated by the syndrome of inappropriate antidiuretic hormone secretion as well as an inability to mobilise osmotically inactive sodium stores. Runners who drink more than to their thirst do so for a reason, and understanding and curtailing this behaviour will probably decrease the incidence of this highly preventable condition. To determine the beliefs about fluid replacement held by runners and whether these beliefs are reflected in hydration behaviours. An online survey was filled out by 197 runners solicited by personal solicitation, e-mail and flyers distributed at three local races in autumn 2009. Most runners (58%) drink only when thirsty. Runners drinking to a set schedule are significantly older, more experienced and faster than those drinking when thirsty. Gastrointestinal distress is the most frequently cited (71.5%) reason to avoid overhydration. Runners have a poor understanding of the physiological consequences of hydration behaviours that frequently reflect messages of advertising. Runners at highest risk of EAH exhibit behaviour that is shaped by their beliefs about the benefits and risks of hydration. These beliefs are frequently based on misconceptions about basic exercise physiology.
With the rising popularity of ultradistance sports events lasting from 6 to 24 hours or multiple days, athletes are consulting registered dietitians for specialized dietary advice. Many dietitians, however, lack experience with these types of events. This article provides basic guidelines for fueling the ultradistance athlete. The goals are to maintain normal hydration and blood glucose levels, which can be done by enforcing programmed drinking (approximately 250 to 500 mL/15 minutes, depending on the athlete’s sweat rate and environmental temperature) and programmed eating (1 to 1.5 + g of carbohydrate per kilogram of body weight per hour, depending on the athlete’s acceptance of and tolerance to solid and/or liquid foods during exercise). Athletes who compete longer than 6 to 8 hours should consume adequate electrolytes, particularly sodium (approximately 1 g/hour) through either sports drinks or foods. These guidelines are applied to a case study of the 1991 women’s winner of the Race Across America, a 2,930-mile biking event.
The purpose of the present investigation was to assess energy expenditure (EE) and energy intake (EI) during a continuous 24-hour treadmill run. EE was determined from heart rate (HR) telemetry, utilizing a linear relationship between VO 2 and HR obtained during a maximal exercise test. EE was also estimated using a common metabolic calculation. The 51 year-old male ultra-marathon runner completed 160 km in 21 hours 59 minutes, and amassed 172 km in 24 hours. Subject's HR averaged 119 ± 8 beats/min and average hourly HR changed as a function of hourly velocity (r = 0.80). Total EE estimated from HR telemetry and a metabolic equation was 12,820 and 12,425 Kcals, respectively. Total EI, 4590 kcal, came almost exclusively from carbohydrate. Blood glucose ranged between 8.2 and 4.1 mmol/L, averaging 5.6 ± 1.1 mmol/L. Estimated lipid oxidation accounted for 5,000 Kcals, and oxidation of carbohydrate accounted for another 1,900 Kcals. Remaining energy was likely supplied through direct oxidation of lactate as well as gluconeogenesis. Our results indicate that the subject experienced a substantial caloric deficit similar to that seen in other ultra-marathon runners, but did not exhibit hypoglycemia. We conclude that EI was sufficient to supplement endogenous substrate utilization and maintain euglycemia for the duration of the 24-hour run.
To determine the incidence of exercise-associated hyponatremia (EAH), the associated biochemical measurements and risk factors for EAH, and whether there is an association between postrace blood sodium concentration ([Na+]) and changes in body mass among participants in the 2009 Western States Endurance Run, a 161-km mountain trail run. Change in body mass, postrace [Na+], and blood creatine phosphokinase (CPK) concentration, and selected runner characteristics were evaluated among consenting competitors. Of the 47 study participants, 14 (30%) had EAH as defined by a postrace [Na+] <135 mmol/L. Postrace [Na+] and percent change in body mass were directly related (r = .30, P = .044), and 50% of those with EAH had body mass losses of 3-6%. EAH was unrelated to age, sex, finish time, or use of nonsteroidal anti-inflammatory drugs during the run, but those with EAH had completed a smaller (P = .03) number of 161-km ultramarathons. The relationship of CPK levels to postrace [Na+] did not reach statistical significance (r = -.25, P = .097). EAH was common (30%) among finishers of this 161-km ultramarathon and it was not unusual for those with EAH to be dehydrated. As such, changes in body mass should not be relied upon in the assessment for EAH during 161-km ultramarathons.
Even pacing has been recommended for optimal performances in running distances up to 100 km. Trail ultramarathons traverse varied terrain, which does not allow for even pacing. This study examined differences in how runners of various abilities paced their efforts in the Western States Endurance Run (WSER), a 161 km trail ultramarathon in North America, under hot vs cooler temperatures. Temperatures in 2006 (hot) and 2007 (cooler) ranged from 7-38°C and 2-30°C, respectively. Arrival times at 13 checkpoints were recorded for 50 runners who finished the race in both years. After stratification into three groups based on finish time in 2007 (<22, 22-24, 24-30 h), paired t tests were used to compare the difference in pace across checkpoints between the years within each group. The χ2 test was used to compare differences between the groups on the number of segments run slower in the hot vs cooler years. For all groups, mean pace across the entire 161 km race was slower in 2006 than in 2007 (9:23 ± 1:13 min/km vs 8:42 ± 1:15 min/km, P < .001) and the pace was slower from the start of the race when temperatures were still relatively cool. Overall, the <22 h cohort ran slower in 2006 than 2007 over 12 of the 14 segments examined, the 22-24 h cohort was slower across 10 of the segments, and the >24 h cohort was slower across only 6 of the segments χ(2)2 = 6.00, P = .050). Comparable pacing between the 2 y corresponded with onset of nighttime and cooling temperatures. Extreme heat impairs all runners' ability to perform in 161 km ultramarathons, but faster runners are at a greater disadvantage compared with slower competitors because they complete a greater proportion of the race in the hotter conditions.
The fluid and food intakes of 7 male participants in a 100-km ultramarathon were recorded. The mean exercise time was 10 hr 29 min. Nutrient analysis revealed a mean intrarace energy intake of 4,233 kJ, with 88.6% derived from carbohydrate, 6.7% from fat, and 4.7% from protein. Fluid intake varied widely, 3.3-11.1 L, with a mean of 5.7 L. The mean decrease in plasma volume at 100 km was 7.3%, accompanied by an estimated mean sweat rate of 0.86 Blood glucose concentrations remained normal during the event, and free fatty acids and glycerol were elevated both during and at the conclusion of the event. No significant correlations were found between absolute amounts and rates of ingestion of carbohydrate and/or fluid and race performance.