Sports foods and dietary supplements for optimal function and performance enhancement in track and field athletes

Numerous nutritional products are marketed with claims of optimizing athlete health and function and/or enhancing performance. Products that fall under the banner of “Sports Foods” or “Dietary Supplements,” may be used to support performance during training and competition or for enhancing aspects of training adaptation, recovery, immune function, and/or overall athlete health. Effective marketing campaigns and athlete endorsements may convince us that certain sports foods and supplements are fundamental in allowing athletes to reach their sporting goals. However, this approach is naive in understanding the true foundations of athlete success, such as the inherent genetic predisposition for athletic characteristics, the many hours of well-structured/periodized training, appropriate underlying nutrition, adequate sleep and recovery, and of course, good overall physical and mental health. Nevertheless, if these variables are all accounted for, there may be a role for sports foods and dietary supplements in an athlete’s training and competition routine, particularly within elite sport where marginal performance gains are pursued. The following review presents general considerations for track-and-field athletes using sports foods and dietary supplements to enhance performance, in addition to exploring the potential therapeutic/prophylactic use of these nutritional aids

Considerations for the consumption of vitamin and mineral supplements in athlete populations

Vitamins and minerals are of fundamental importance to numerous human functions that are essential to optimise athlete performance. Athletes incur a high turnover of key vitamins and minerals and are therefore dependent on sufficient energy intake to replenish nutrient stores. However, many athletes are poor at servicing their energy replenishment needs, especially female athletes, and although a ‘food first approach’ to meeting nutrient requirements is the primary goal, it may be important for some athletes to consider a vitamin and/or mineral supplement to meet their daily needs. When working to determine if an athlete requires vitamin or mineral supplements, practitioners should use a robust framework to assess the overall energy requirements, current dietary practices and the biological and clinical status of their athletes. Of note, any supplementation plan should account for the various factors that may impact the efficacy of the approach (e.g. athlete sex, the nutrient recommended dietary intake, supplement dose/timing, co-consumption of other foods and any food–drug interactions). Importantly, there are numerous vitamins and minerals of key importance to athletes, each having specific relevance to certain situations (e.g. iron and B vitamins are significant contributors to haematological adaptation, calcium and vitamin D are important to bone health and folate is important in the female athlete); therefore, the appropriate supplement for a given situation should be carefully considered and consumed with the goal to augment an athlete’s diet

Prevalence and distribution of Schistosoma haematobium infection among school children living in southwestern shores of Lake Malawi

BACKGROUND: The prevalence of Schistosoma haematobium infection has been shown to be about 23.7% among children living in the lakeshore areas of Malawi, with reinfection rates of about 30% to 40%. This study aimed to determine the current prevalence and distribution of S. haematobium infection in school children along the southwestern shores of Lake Malawi and examine the control interventions present in the area. METHODS: This prospective cross-sectional study was conducted in primary schools. School children were enrolled, demographic data were collected, and urine samples were submitted for analysis on macrohaematuria, microhaematuria, and S. haematobium eggs. A questionnaire was administered to 3 health facilities on diagnosis and treatment of schistosomiasis, as well as the control interventions against it. RESULTS: Four hundred children (174 males and 226 females) were enrolled from 7 primary schools. Mean participant age was 9.57 years (range 7 to 12 years). Fifty children (12.5%) had S. haematobium eggs detected in their urine, with the mean egg count being 15/10 mL. The highest infection intensity category (≥ 50 eggs/10mL) was seen in 10 children (2.5%). Prevalence varied significantly between the schools, with rates ranging from 0% to 20%. Schools with higher prevalence rates were located farther away from the nearest public hospital that provides treatment free of charge. Prevalence correlated with previous history of mass chemotherapy in schools. Mass chemotherapy, health education, and improved water supply and sanitation were some of the interventions that contributed to lower prevalence rates in some areas. CONCLUSIONS: Schistosomiasis prevalence around southwestern Lake Malawi was lower than previously reported, owing to control interventions focusing on health education, improved water supply, sanitation, and mass chemotherapy. Consistent and uniform interventions can reduce prevalence further and sustain control. As prevalence falls, diagnostics can identify high transmission areas, monitor disease trends, and guide evidence-based control strategies

Dietary iron and the elite dancer

Dancers are an athlete population at high risk of developing iron deficiency (ID). The aesthetic nature of the discipline means dancers potentially utilise dietary restriction to meet physique goals. In combination with high training demands, this means dancers are susceptible to problems related to low energy availability (LEA), which impacts nutrient intake. In the presence of LEA, ID is common because of a reduced mineral content within the low energy diet. Left untreated, ID becomes an issue that results in fatigue, reduced aerobic work capacity, and ultimately, iron deficient anaemia (IDA). Such progression can be detrimental to a dancer’s capacity given the physically demanding nature of training, rehearsal, and performances. Previous literature has focused on the manifestation and treatment of ID primarily in the context of endurance athletes; however, a dance-specific context addressing the interplay between dance training and performance, LEA and ID is essential for practitioners working in this space. By consolidating findings from identified studies of dancers and other relevant athlete groups, this review explores causal factors of ID and potential treatment strategies for dancers to optimise absorption from an oral iron supplementation regime to adequately support health and performance

Dietary iron and the elite dancer

Dancers are an athlete population at high risk of developing iron deficiency (ID). The aesthetic nature of the discipline means dancers potentially utilise dietary restriction to meet physique goals. In combination with high training demands, this means dancers are susceptible to problems related to low energy availability (LEA), which impacts nutrient intake. In the presence of LEA, ID is common because of a reduced mineral content within the low energy diet. Left untreated, ID becomes an issue that results in fatigue, reduced aerobic work capacity, and ultimately, iron deficient anaemia (IDA). Such progression can be detrimental to a dancer’s capacity given the physically demanding nature of training, rehearsal, and performances. Previous literature has focused on the manifestation and treatment of ID primarily in the context of endurance athletes; however, a dance-specific context addressing the interplay between dance training and performance, LEA and ID is essential for practitioners working in this space. By consolidating findings from identified studies of dancers and other relevant athlete groups, this review explores causal factors of ID and potential treatment strategies for dancers to optimise absorption from an oral iron supplementation regime to adequately support health and performance

Timing is everything, but does it really matter? Impact of 8-weeks morning versus evening iron supplementation in ballet and contemporary dancers

The effectiveness of a morning versus evening oral iron supplement strategy to increase iron stores was explored. Ballet and contemporary dancers with serum ferritin (sFer) \u3c 50 g/L (n = 14), were supplemented daily with 105 mg elemental oral iron in either the morning (FeAM) or evening (FePM) for 8 weeks. A control group (n = 6) with sFer \u3e 50 g/L were given no supplement over the same period. Dancers’ sFer were measured at baseline and post-intervention. Assessment of daily training load, dietary intake, and menstruation were made. A significant interaction (p \u3c 0.001) showed the within group sFer change over the 8-week intervention in FeAM (+25.9 ± 10.5 g/L) and FePM, (+22.3 ± 13.6 g/L) was significantly different to CON (−30.17 ± 28.7 g/L; both p = 0.001). This change was not different between FeAM and FePM (p = 0.778). sFer levels within FeAM and FePM significantly increased over the 8-weeks; however, they significantly decreased in the CON group (all p \u3c 0.05). Post-intervention sFer levels were no longer different between the three groups (p \u3e 0.05). Training load, dietary intake, and number of menstrual cycles incurred were similar between FeAM and FePM (p \u3e 0.05). Oral iron supplementation in either the morning or evening appears equally effective in increasing sFer levels in dancers with sub-optimal iron status

Pre-Altitude Serum Ferritin Levels and Daily Oral Iron Supplement Dose Mediate Iron Parameter and Hemoglobin Mass Responses to Altitude Exposure

Purpose : To investigate the influence of daily oral iron supplementation on changes in hemoglobin mass (Hbmass) and iron parameters after 2–4 weeks of moderate altitude exposure.Methods :Hematological data collected from 178 athletes (98 males, 80 females) exposed to moderate altitude (1,350–3,000 m) were analysed using linear regression to determine how altitude exposure combined with oral iron supplementation influenced Hbmass, total iron incorporation (TII) and blood iron parameters [ferritin and transferrin saturation (TSAT)]. Results :Altitude exposure (mean ± s: 21 ± 3 days) increased Hbmass by 1.1% [-0.4, 2.6], 3.3% [1.7, 4.8], and 4.0% [2.0, 6.1] from pre-altitude levels in athletes who ingested nil, 105 mg and 210 mg respectively, of oral iron supplement daily. Serum ferritin levels decreased by -33.2% [-46.9, -15.9] and 13.8% [-32.2, 9.7] from pre-altitude levels in athletes who supplemented with nil and 105 mg of oral iron supplement daily, but increased by 36.8% [1.3, 84.8] in athletes supplemented with 210 mg of oral iron daily. Finally, athletes who ingested either 105 mg or 210 mg of oral iron supplement daily had a greater TII compared with non-supplemented athletes (0 versus 105 mg: effect size (d) = -1.88 [-2.56, -1.17]; 0 versus 210 mg: effect size (d) = -2.87 [-3.88, -1.66]). Conclusion :Oral iron supplementation during 2–4 weeks of moderate altitude exposure may enhance Hbmass production and assist the maintenance of iron balance in some athletes with low pre-altitude iron stores

Iron supplementation and altitude: Decision making using a regression tree

[No abstract available

Evening electronic device use and sleep patterns in athletes

The present study aimed to investigate pre-sleep behaviours (including evening electronic device use) and sleep quantity in well-trained athletes. Seventy well-trained athletes (44 females, 26 males) aged 21 ± 4 y from a range of team and individual sports were asked to complete an online sleep diary for 7 days. The sleep diary included questions about pre-sleep behaviours (e.g. napping, caffeine intake), electronic device use in the 2 h prior to bedtime (e.g. type of device and duration of use) and sleep (e.g. time in bed, sleep onset latency). On average, athletes spent 8:20 ± 1:21 h in bed each night. Associations between age, time in bed and sleepiness suggested that younger athletes spent more time in bed (B = -0.05, p = 0.001) but felt sleepier (r = -0.32, p < 0.01) than older athletes. On average, athletes mostly used electronic devices for 0–30 min prior to sleep. The use of multiple devices in the evening was associated with more perceived difficulty in falling asleep (B = 0.22, p = 0.03), but no associations existed with other sleep variables. In summary, younger athletes may require later start times or improved sleep quality to resolve excessive sleepiness

The impact of syphilis screening among female sex workers in China: a modelling study.

BACKGROUND: In China, female sex workers (FSWs) are at high risk of syphilis infection, but are hard to reach for interventions. Point-of-care testing introduces opportunities for expanding syphilis control measures. Modelling is used to estimate the impact of using rapid tests to screen FSWs for syphilis. In other settings, modelling has predicted large rebounds in infectious syphilis following screening, which may undermine any impact achieved. METHODS: A deterministic syphilis transmission model among FSWs and clients was fitted to data from Yunnan Province (FSW syphilis prevalence = 7.5%), and used to estimate the impact of rapid syphilis testing and treatment for FSWs. Impact projections were compared for different model structures that included risk heterogeneity amongst FSWs, incoming syphilis infections amongst new FSWs and clients and re-infection from FSWs' regular non-commercial partners. The rebound in syphilis prevalence after screening ceased was explored. RESULTS: All model structures suggest yearly syphilis screening could substantially reduce (by 72-88%) syphilis prevalence amongst FSWs in this setting over five years. However, incoming syphilis infections amongst new FSWs and clients or re-infections from regular non-commercial partners of FSWs can considerably reduce (>30%) the proportion of infections averted. Including heterogeneity in risk amongst FSWs had little effect upon the proportion of infections averted. In this setting, the rebound in syphilis prevalence after screening ceased is predicted to be slight, but it could be large in high prevalence settings. CONCLUSIONS: Rapid test screening could dramatically reduce syphilis prevalence amongst hard-to-reach groups, but strategies to reduce re-infection from regular non-commercial partners are needed to maximise impact