Relationship between the Ingestion of a Polyphenol-Rich Drink, Hepcidin Hormone, and Long-Term Training.

The effects of polyphenol-rich foods on the iron status of athletes, as well as the effect of physical training on the hormone hepcidin, implicated in iron metabolism, are not clear. We investigated the influence on iron metabolism of a long-term training intervention of 120 days, measuring the hepcidin concentration in the plasma of 16 elite triathletes, and the effect of the ingestion of 200 mL of either aronia-citrus juice or a placebo drink for 45 days, in a crossover design. The highest plasma hepcidin concentrations were observed at the beginning of the study (116 ± 63 nM) and levels steadily decreased until the end of the intervention (final value 10 ± 7.5 nM). Long-term training might reduce inflammation and, hence, could be responsible for the decrease in hepcidin in triathletes. Polyphenols from aronia-citrus juice did not interfere in iron absorption, as we did not observe significant differences between the intake of the placebo drink or juice with regard to hepcidin levels. Further studies are required to ascertain the time and conditions necessary to restore hepcidin levels, which reflect the iron status of triathletes.

Assessment of oxidative stress markers and prostaglandins after chronic training of triathletes.

The present study established the pattern of isoprostanes (IsoPs) and prostaglandins metabolites (PGMs) in urine after triathlon training. Fifteen Caucasian triathletes - 5 women and 10 men - performed 793 and 1603 Objective Load Scales, respectively. The optimization of urine hydrolysis conditions, concerning to the type of buffer, the units of hydrolytic enzyme added, and the pH, allowed precise quantification of these metabolites by UPLC-MS/MS, avoiding the under-estimation of their concentrations that occurred in previous studies. Their rate of conjugation ranged between 36% and 100%. This implies significant importance since it supposes non-detection of some IsoPs and PGMs totally conjugated with glucuronic acid developed by other previous methodologies. Among the 13 compounds analyzed, this assay detected and characterized 4 IsoPs and 3 PGMs in the triathletes' urine. The PGMs tetranor-PGEM and 11ß-PGF(2α) and the IsoP 8-iso-PGF(2α), showed lower concentrations after the training program, whereas the PGMs 6-keto-PGF(1α) increased (vascular PGI(2) metabolite). In fact, their pattern in the triathletes' urine indicated that their variation may have been related with the physical activity. Due to its high variation, 6-keto PGF(1α) stood out as a useful marker of the vasodilation and inhibition of the platelet aggregation of the PGI(2) linked to the physical exercise. The data obtained provided a global picture of changes in lipid peroxidation and vascular events as a consequence of chronic exercise.

Individual hemoglobin mass response to normobaric and hypobaric "live high-train low": A one-year crossover study.

The purpose of this research was to compare individual hemoglobin mass (Hbmass) changes following a live high-train low (LHTL) altitude training camp under either normobaric hypoxia (NH) or hypobaric hypoxia (HH) conditions in endurance athletes. In a crossover design with a one-year washout, 15 male triathletes randomly performed two 18-day LHTL training camps in either HH or NH. All athletes slept at 2,250 meters and trained at altitudes <1,200 meters. Hbmass was measured in duplicate with the optimized carbon monoxide rebreathing method before (pre) and immediately after (post) each 18-day training camp. Hbmass increased similarly in HH (916-957 g, 4.5 ± 2.2%, P < 0.001) and in NH (918-953 g, 3.8 ± 2.6%, P < 0.001). Hbmass changes did not differ between HH and NH (P = 0.42). There was substantial interindividual variability among subjects to both interventions (i.e., individual responsiveness or the individual variation in the response to an intervention free of technical noise): 0.9% in HH and 1.7% in NH. However, a correlation between intraindividual ΔHbmass changes (%) in HH and in NH (r = 0.52, P = 0.048) was observed. HH and NH evoked similar mean Hbmass increases following LHTL. Among the mean Hbmass changes, there was a notable variation in individual Hbmass response that tended to be reproducible.NEW & NOTEWORTHY This is the first study to compare individual hemoglobin mass (Hbmass) response to normobaric and hypobaric live high-train low using a same-subject crossover design. The main findings indicate that hypobaric and normobaric hypoxia evoked a similar mean increase in Hbmass following 18 days of live high-train low. Notable variability and reproducibility in individual Hbmass responses between athletes was observed, indicating the importance of evaluating individual Hbmass response to altitude training.

DNA catabolites in triathletes: effects of supplementation with an aronia-citrus juice (polyphenols-rich juice).

In this study we analyzed whether our aronia-citrus juice (ACJ, the composition is based on a mixture of 95% citrus juice with 5% of Aronia melanocarpa juice), rich in polyphenols, and physical exercise had an effect on seven catabolites of DNA identified in plasma and on a urine isoprostane (8-iso-PGF2α). Sixteen elite triathletes on a controlled diet for triathlon training (45 days) were used in this clinical trial. Our results show a decrease in the 8-hydroxy-2'-deoxyguanosine concentration due to chronic physical exercise. The ACJ intake and physical exercise maintained the guanosine-3',5'-cyclic monophosphate plasmatic concentrations and decreased the concentration of 8-hydroxyguanine as well as urinary values of 8-iso-PGF2α. Finally, we observed a significant increase in the 8-nitroguanosine levels in triathletes after ACJ intake, compared to the placebo stage. It is concluded that the combination of the intake of ACJ, rich in polyphenolic compounds, with adequate training was able to influence the plasmatic and urinary values of oxidative stress biomarkers. This suggests a positive effect on the oxidative damage and potential associations with DNA repair mechanisms.

Similar Hemoglobin Mass Response in Hypobaric and Normobaric Hypoxia in Athletes.

PURPOSE: To compare hemoglobin mass (Hb(mass)) changes during an 18-d live high-train low (LHTL) altitude training camp in normobaric hypoxia (NH) and hypobaric hypoxia (HH). METHODS: Twenty-eight well-trained male triathletes were split into three groups (NH: n = 10, HH: n = 11, control [CON]: n = 7) and participated in an 18-d LHTL camp. NH and HH slept at 2250 m, whereas CON slept, and all groups trained at altitudes <1200 m. Hb(mass) was measured in duplicate with the optimized carbon monoxide rebreathing method before (pre-), immediately after (post-) (hypoxic dose: 316 vs 238 h for HH and NH), and at day 13 in HH (230 h, hypoxic dose matched to 18-d NH). Running (3-km run) and cycling (incremental cycling test) performances were measured pre and post. RESULTS: Hb(mass) increased similar in HH (+4.4%, P < 0.001 at day 13; +4.5%, P < 0.001 at day 18) and NH (+4.1%, P < 0.001) compared with CON (+1.9%, P = 0.08). There was a wide variability in individual Hb(mass) responses in HH (-0.1% to +10.6%) and NH (-1.4% to +7.7%). Postrunning time decreased in HH (-3.9%, P < 0.001), NH (-3.3%, P < 0.001), and CON (-2.1%, P = 0.03), whereas cycling performance changed nonsignificantly in HH and NH (+2.4%, P > 0.08) and remained unchanged in CON (+0.2%, P = 0.89). CONCLUSION: HH and NH evoked similar Hb(mass) increases for the same hypoxic dose and after 18-d LHTL. The wide variability in individual Hb(mass) responses in HH and NH emphasizes the importance of individual Hb(mass) evaluation of altitude training.

Relationship between rowing ergometer performance and physiological responses to upper and lower body exercises in rowers.

The aim of this investigation was to compare the physiological responses of 2000 m rowing ergometer test with 7-min bench pull and leg press tests. We hypothesised that leg press exercise contributes to 2000 m rowing ergometer test results, rather than bench pull performed by arms. College level rowers (n=12) performed 2000 m rowing test and after one day 7-min bench pull and leg press (50% from the 1 RM). Stroke rate, heart rate (HR), blood lactate (LA) and ratings of perceived exertion (RPE) were measured during all tests. The number of repetitions was highest during 2000 m rowing test (194.2+/-19.5) and lowest during bench pull (122.6+/-17.7) (during leg press 173.5+/-11.8). Differences between 2000 m rowing test, leg press and bench pull tests were significant in mean and maximal HR. In LA concentration, the highest values were at 3rd min of recovery after rowing test (14.8+/-1.7 mmol l(-1)). Between bench pull (8.8+/-1.9 and 8.5+/-2.7 mmol l(-1)) and leg press (11.8+/-2.5 and 11.2+/-2.3 mmol l(-1)) tests, the difference in LA concentration was not significant (p>0.05). Ratings of perceived exertion were highest in 2000 m rowing test (19.3+/-0.9), difference with leg press and bench pull tests was not significant. There were significant relationships in mean and maximal HR (r=0.713-0.767) and Borg scale (r=0.764) during rowing test and leg press. The number of repetitions during leg press exercise correlated significantly with rowing test time (r=-0.677). In conclusion, this study suggests that in rowers there are major differences in the physiological adaptation to upper body and leg exercise, performed at similar intensities. Leg press exercise could be used to measure sport-specific strength endurance in rowers.