This review examines the hypothesis that vitamin and mineral status in athletes is inadequate for optimal sports performance. The review is based on indicators determined from blood and on studies published since 1980. Most of the studies did not find micronutrient status in athletes to be different from untrained controls. The serum ferritin concentration in females was lower than in males (27 vs. 78 μg · L−1), and the prevalence of low serum ferritin concentration was higher in female athletes than in untrained female controls (37 vs. 23%). Supplementation of water-soluble vitamins and iron was associated with an improvement in the corresponding indicators. Excluding a few studies with mildly anemic subjects, improvements in indicators of micronutrient status were not associated with enhanced athletic performance. Consequently, the levels of indicators of micronutrient status seen in athletes' blood were apparently compatible with optimal physical performance.
Tuomo Rankinen, Mikael Fogelholm, Urho Kujala, Rainer Rauramaa and Matti Uusitupa
Dietary intakes, trace element status, and anthropometric measures were studied in 12- to 13-year-old boys (n = 49) playing ice hockey (AB) and in 11- to 12-year-old girls who were gymnasts, figure skaters, and runners (AG; n = 43), Thirty-five boys (CB) and 53 girls (CG) not involved in supervised sports were controls. After adjustment for sexual maturation, ABs had larger upper arm muscle circumference than CBs. The sum of four skinfolds was smaller in AGs than in CGs. The intake of energy and all micronutrients examined was higher in ABs than in CBs. Micronu-trient Intakes were not different between AGs and CGs. Compared to CBs, serum ferritin and copper concentrations were lower, but serum zinc concentration was higher in ABs. No differences in trace element status were found between AGs and CGs. Blood investigations did not indicate inadequate trace element status in any of the groups studied.
Mikael Fogelholm, Jaana Suni, Marjo Rinne, Pekka Oja and Ilkka Vuori
Minna Aittasalo, Matti Pasanen, Mikael Fogelholm and Katriina Ojala
To examine the validity and repeatability of a short leisure time physical activity (LTPA) questionnaire during pregnancy.
Seventy-nine women with uncomplicated pregnancies and weeks’ gestation ≤ 33 participated. After the first questionnaire (LTPAQ1) they entered 7-day LTPA and pedometer counts in a logbook and completed the second LTPA questionnaire (LTPAQ2). Validity was assessed with Spearman’s rank correlation coefficients by comparing LTPAQ2 with pedometer counts and logbook. For describing repeatability, change in the mean, geometric mean ratio, typical error, coefficient of variation (CV, %) and Bland-Altman plots were used.
Forty-five (57%) and 47 (59%) women were available for pedometer and logbook comparisons and 49 (62%) for repeatability assessment. LTPAQ2 showed no correlation with pedometer but moderate correlation with the logbook for the frequency of moderate to vigorous-intensity LTPA (rs = 0.68, 95% CI 0.48 to 0.81). In repeatability, the typical error for frequency estimates varied from 1.2 to 3.7 sessions and CV for duration from 119 to 369%. The corresponding values for systematic error were -1.0 to 0.3 sessions and 4 to 36%. The 95% limits of agreement for single variables were large.
The questionnaire was valid for assessing moderate to vigorous-intensity LTPA but its individual repeatability proved weak.
Maria Heikkilä, Raisa Valve, Mikko Lehtovirta and Mikael Fogelholm
The nutrition knowledge of athletes and coaches is often inadequate. However, athletes need sufficient knowledge of this subject to understand the importance of food choices for their athletic performance, recovery, and overall health. Adequate nutrition knowledge and skills are important for coaches because they are often the most significant source of nutrition knowledge for their athletes. Most previous nutrition knowledge studies have been carried out in team sports and outside Scandinavia. The aim of this study, therefore, was to evaluate the nutrition knowledge of Finnish endurance athletes (156 males and 156 females; age = 17.9 ± 1.2 years) and their coaches (69 males and 25 females; age = 44.3 ± 12.3 years). The three main sports among the participants were cross-country skiing (n = 53 coaches and n = 111 athletes), orienteering (n = 13 and n = 110), and biathlon (n = 6 and n = 38). On average, the coaches (N = 94) answered 81% ± 9% of the 79 nutrition questionnaire items correctly, whereas the respective result was 73% ± 9% among the athletes (N = 312). The coaches had significantly (p < .001) better nutrition knowledge of all the five subcategories of the questionnaire, whereas the “dietary supplements” and “nutrition recommendations for endurance athletes” subcategories appeared particularly difficult for the athletes. The average nutrition knowledge score of athletes was relatively low. As nutrition knowledge may have a positive association with athletes’ food choices and subsequent dietary intake, Finnish endurance athletes and coaches would benefit from enhanced nutrition education.
G. Mikael Fogelholm, Hannu K. Näveri, Kai T.K. Kiilavuori and Matti H.A. HärkÖnen
Using a double-blind, crossover protocol, we studied the possible effects of a 4-day combined L-arginine, L-ornithine, and L-lysine supplementation (each 2 g/day, divided into two daily doses) on 24-hr level of serum human growth hormone (hGH) and insulin in 11 competitive weightlifters, ages 19 to 35 yrs. Three similar daily hGH peaks, seemingly preceded by a decrease in serum insulin concentration, were found during both amino acid and placebo supplementation. Supplementation did not affect the physiological variation of serum hGH concentration (treatment and treatment × time interaction: p=0.43–0.55). Analogously, serum insulin levels were not higher after amino acid supplementation. Therefore the ergogenic value of lowdose oral amino acid supplementation in increasing hGH or insulin secretion seems questionable.
Fred Brouns, Mikael Fogelholm, Gerrit van Hall, Anton Wagenmakers and Wim H.M. Saris
This study tested the hypothesis that a 3-week oral lactate supplementation affects postexercise blood lactate disappearance in untrained male subjects. Fifteen men were randomly assigned to either a lactate supplementation (n = 8) or a placebo (n = 7) treatment. During the treatment period they drank an oral lactate or a maltodextrin (placebo) supplement twice a day. The lactate drink contained 10 g of lactate as calcium, sodium, and potassium salts. Blood lactate concentrations were studied before, during, and immediately after three exercise tests, both pre-and posttreatment. Peak lactate values for placebo (PL) or lactate (L) treatment groups during different tests were as follows: Test 1 PL, 13.49 ± 3.71; L, 13.70 ± 1.90; Test 2 PL, 12.64 ± 2.32; L, 12.00 ± 2.23; Test 3 PL, 12.29 ± 2.92; L, 11.35 ± 1.38 and were reached 3 min postexercise. The decrease in blood lactate during the long (30- to 45-min) recovery periods amounted to @ 10 mmol/L. Blood lactate changes were highly reproducible. However, a 3-week oral lactate supplementation did not result in differences in lactate disappearance. This study does not support the hypothesis that regular oral lactate intake at rest enhances the removal of lactate during and following exercise, that is, not with the given lactate load and supplementation period.
Mikael Fogelholm, Inkeri Ruokonen, Juha T. Laakso, Timo Vuorimaa and Jaakko-Juhani Himberg
By means of a 5-week vitamin B-complex .supplementation, associations between indices of vitamin B1, B2, and B6, status (activation coefficients [AC] for erythrocyte transketolase, glutathione reductase, and aspartate aminotransferase) and exercise-induced blood lactate concentration were studied. Subjects, 42 physically active college students (18–32 yrs), were randomized into vitamin (n=22) and placebo (n=20) groups. Before the supplementation there were no differences in ACs or basal enzyme activities between the groups. The ACs were relatively high, suggesting marginal vitamin status. In the vitamin group, all three ACs were lower (p<0.0001) after supplementation: transketolase decreased from l. 16 (1.14–1.18) (mean and 95% confidence interval) to 1.08 (1.06–1.10); glutathione reductase decreased from 1.33 (1.28–1.39) to 1 .I4 (1.1 1–1.17); and aspartate aminotransferase decreased from 2.04 (1.94–2.14) to 1.73 (1.67–1.80). No changes were found after placebo. Despite improved indices of vitamin status, supplementation did not affect exercise-induced blood lactate concentration. Hence no association was found between ACs and blood lactate. It seems that marginally high ACs do not necessarily predict altered lactate metabolism.
Jani P. Vaara, Heikki Kyröläinen, Mikael Fogelholm, Matti Santtila, Arja Häkkinen, Keijo Häkkinen and Tommi Vasankari
The aim was to study the relationships between different domains of physical activity and cardiovascular risk factors and physical fitness.
781 young men participated. Self-reported leisure-time (LTPA), commuting (CPA) and occupational (OPA) activity were determined. Blood pressure, s-HDL-cholesterol, s-triglycerides and s-LDL-cholesterol, and glucose were measured. The continuous cardiovascular disease (CVD) risk factor score was calculated from the z-score mean of each cardiovascular risk factor. The cutpoint was defined as 1 standard deviation above the mean. Cardiorespiratory and muscular fitness were measured.
The likelihood of CVD risk factor score was higher in moderate [OR 1.99 (95% CI 1.21–3.28)] and low [1.87 (1.16–3.02)] CPA groups compared with the high group, whereas neither low nor moderate LTPA or OPA groups showed similar associations after adjustments. Low OPA combined either with low LTPA [2.01 (1.08–3.74)] or low CPA [1.90 (1.05–3.44)] had a higher likelihood for CVD risk factor compared with combined moderate-high categories after adjustments. LTPA was positively associated with all physical fitness parameters, CPA with cardiorespiratory fitness and muscular endurance, and OPA with grip strength.
The results emphasize the beneficial role of CPA regarding CVD risk factor score and stress the avoidance of low physical activity in its different domains.
Mikael Fogelholm, Seppo Rehunen, Carl-Gustav Gref, Juha T. Laakso, Jari Lehto, Lnkeri Ruokonen and Jaakko-Juhani Himberg
This study evaluated how different training periods affect dietary intake and biochemical indices of thiamin, iron, and zinc status in elite Nordic skiers. Subjects.were 17 skiers and 39 controls, ages 18-38 yrs. Dietary data were collected by 7-day food records at 3-month intervals. Coefficient of variation (CV) was used to indicate magnitude of seasonal changes. Energy intake for the year (28 food record days) was 3,802 kcallday (CV 19.1%) in male skiers, 2,754 kcallday (CV 3.7%) in male controls, 2,812 kcallday (CV 9.1%) in female skiers, and 2,013 kcallday (CV 5.9%) in female controls. CVs for thiamin, riboflavin, vitamin C, calcium, magnesium, iron, and zinc intake were 14.1-23.9% (male skiers), 2.9-15.0% (male controls), 4.8-24.5% (female skiers), and 4.3-1 1.5% (female controls). Seasonal changes in energy, carbohydrate, and micronutrient intakes reflected energy expenditure in male endurance athletes particularly. Erythrocyte transketolase activation coefficients and serum ferritin and zinc concentrations did not differ between skiers and controls. Seasonal variations in these biochemical indices of nutritional status were of the same magnitude in skiers and controls, despite large changes in skiers' physical activity.