The Effectiveness of Transdermal Iron Patches in Athletes With Suboptimal Iron Status (Part 1).

The authors compared the effectiveness of two modes of daily iron supplementation in athletes with suboptimal iron stores: oral iron (PILL) versus transdermal iron (PATCH). Endurance-trained runners (nine males and 20 females), with serum ferritin concentrations <50 µg/L, supplemented with oral iron or iron patches for 8 weeks, in a parallel group study design. Serum ferritin was measured at baseline and fortnightly intervals. Hemoglobin mass and maximal oxygen consumption (V˙O2max) were measured preintervention and postintervention in PATCH. A linear mixed effects model was used to assess the effectiveness of each mode of supplementation on sFer. A repeated-measures analysis of variance was used to assess hemoglobin mass and V˙O2max outcomes in PATCH. There was a significant time effect (p < .001), sex effect (p = .013), and Time × Group interaction (p = .009) for sFer. At Week 6, PILL had significantly greater sFer compared with PATCH (15.27 µg/L greater in PILL; p = .019). Serum ferritin was 15.53 µg/L greater overall in males compared with females (p = .013). There were no significant differences in hemoglobin mass (p = .727) or V˙O2max (p = .929) preintervention to postintervention in PATCH. Finally, there were six complaints of severe gastrointestinal side effects in PILL and none in PATCH. Therefore, this study concluded that PILL effectively increased sFer in athletes with suboptimal iron stores, whereas PATCH showed no beneficial effects.

The Effectiveness of Daily and Alternate Day Oral Iron Supplementation in Athletes With Suboptimal Iron Status (Part 2).

The authors compared the effectiveness of daily (DAY) versus alternate day (ALT) oral iron supplementation in athletes with suboptimal iron. Endurance-trained runners (nine males and 22 females), with serum ferritin (sFer) concentrations <50 µg/L, supplemented with oral iron either DAY or ALT for 8 weeks. Serum ferritin was measured at baseline and at fortnightly intervals. Hemoglobin mass (Hbmass) was measured pre- and postintervention in a participant subset (n = 10). Linear mixed-effects models were used to assess the effectiveness of the two strategies on sFer and Hbmass. There were no sFer treatment (p = .928) or interaction (p = .877) effects; however, sFer did increase (19.7 µg/L; p < .001) over the 8-week intervention in both groups. In addition, sFer was 21.2 µg/L higher (p < .001) in males than females. No Hbmass treatment (p = .146) or interaction (p = .249) effects existed; however, a significant effect for sex indicated that Hbmass was 140.85 g higher (p = .004) in males compared with females. Training load (p = .001) and dietary iron intake (p = .015) also affected Hbmass. Finally, there were six complaints of severe gastrointestinal side effects in DAY, but only one in ALT. In summary, both supplement strategies increased sFer in athletes with suboptimal iron status; however, the ALT approach was associated with lower incidence of gastrointestinal upset.

Supplement Use and Behaviors of Athletes Affiliated With an Australian State-Based Sports Institute.

The authors aimed to update knowledge of the use of supplements among Australian athletes at a state-based sports institute. The authors conducted a cross-sectional survey using an online questionnaire to assess the influence of age, sports category, and scholarship category on supplement use. Of 94 completed questionnaires, 82 (87%) indicated supplements in the previous 12 months (mean = 4.9 ± 3.3). No significant difference in supplement usage rate was identified when considering age, scholarship category, or sport category. The most frequently used supplements were sports drinks (70%), caffeine (48%), protein powder (42%), and sports bars (42%). Recovery (63%), health maintenance (59%), and improved energy (50%) were the most frequently reported rationale to use supplements. Allied health professionals and credible online resources were the predominant sources of influence regarding use. However, athletes from lower scholarship categories were more likely to have social media, parents, and siblings influence usage, and age was inversely related to increased influence from parents, social media, physicians not associated with the institute, the Internet, and siblings. Older athletes and those on higher scholarships were more likely to source supplements from training facilities and sports nutrition staff outside of the institute or direct from a supplier, whereas those on lower scholarships tended to rely more on family and friends for their supplements. Findings from this study show a high prevalence of supplement use and are the first to show an influence of social media, particularly in younger athletes. Opportunities exist to optimize how athletes are informed regarding supplement use and organizational and supplement policy.

Evening electronic device use: The effects on alertness, sleep and next-day physical performance in athletes.

The aim of the present study was to investigate the influence of different types of tasks performed with or without an electronic device (tablet) on pre-sleep alertness, subsequent sleep quality and next-day athletic performance. Eight highly trained netball players attended a sleep laboratory for pre-sleep testing, polysomnographic sleep monitoring and next-day physical performance testing on 5 separate occasions (1 familiarisation and 4 experimental sessions). For 2 h prior to bedtime, athletes completed cognitively stimulating tasks (puzzles) or passive tasks (reading) with or without a tablet. Sleepiness tended to be greater after reading compared to completing puzzles without a tablet (d = 0.80), but not with a tablet. Melatonin concentration increased more so after reading compared to completing puzzles on a tablet (P = 0.02). There were no significant differences in sleep quality or quantity or next-day athletic performance between any of the conditions. These data suggest that using a tablet for 2 h prior to sleep does not negatively affect subsequent sleep or next-day performance in athletes.

Influence of post-exercise hypoxic exposure on hepcidin response in athletes.

PURPOSE: To assess the influence of a simulated altitude exposure (~2,900 m above sea level) for a 3 h recovery period following intense interval running on post-exercise inflammation, serum iron, ferritin, erythropoietin, and hepcidin response. METHODS: In a cross-over design, ten well-trained male endurance athletes completed two 8 × 3 min interval running sessions at 85 % of their maximal aerobic velocity on a motorized treadmill, before being randomly assigned to either a hypoxic (HYP: F IO2 ~0.1513) or a normoxic (NORM: F IO2 0.2093) 3 h recovery period. Venous blood was collected pre- and immediately post-exercise, and after 3 and 24 h of recovery. Blood was analyzed for interleukin-6, serum iron, ferritin, erythropoietin, and hepcidin. RESULTS: Interleukin-6 was significantly elevated (p < 0.01) immediately post-exercise compared to baseline (NORM: 1.08 ± 0.061 to 3.12 ± 1.80) (HYP: 1.32 ± 0.86 to 2.99 ± 2.02), but was not different between conditions. Hepcidin levels were significantly elevated (p < 0.01) at 3 h post-exercise for both conditions when compared to baseline (NORM: 3.25 ± 1.23 to 7.40 ± 4.00) (HYP: 3.24 ± 1.94 to 5.42 ± 3.20), but were significantly lower (p < 0.05) in the HYP trial compared to NORM. No significant differences existed between HYP and NORM for erythropoietin, serum iron, or ferritin. CONCLUSION: Simulated altitude exposure (~2,900 m) for 3 h following intense interval running attenuates the peak hepcidin levels recorded at 3 h post-exercise. Consequently, a hypoxic recovery after exercise may be useful for athletes with compromised iron status to potentially increase acute dietary iron absorption.

Hydration and urinary pseudoephedrine levels after a simulated team game.

This study investigated the influence of dehydration on urinary levels of pseudoephedrine (PSE) after prolonged repeated effort activity. Fourteen athletes performed a simulated team game circuit (STGC) outdoors over 120 min under three different hydration protocols: hydrated (HYD), dehydrated (DHY) and dehydrated + postexercise fluid bolus (BOL). In all trials, a 60 mg dose of PSE was administered 30 min before trial and at half time of the STGC. Urinary PSE levels were measured before drug administration and at 90 min postexercise. In addition, body mass (BM) changes and urinary specific gravity (USG), osmolality (OSM), creatinine (Cr), and pH values were recorded. No differences in PSE levels were found 90 min postexercise between conditions (HYD: 208.5 ± 116.5; DHY: 238.9 ± 93.5; BOL: 195.6 ± 107.3 µg · ml(-1)), although large variations were seen within and between participants across conditions (range: 33-475 µg · ml(-1): ICC r = .03-0.16, p > .05). There were no differences between conditions in USG, OSM, pH or PSE/Cr ratio. In conclusion, hydration status did not influence urinary PSE levels after prolonged repeated effort activity, with ~70% of samples greater than the WADA limit (>150 µg · ml(-1)), and ~30% under. Due to the unpredictability of urinary PSE values, athletes should avoid taking any medications containing PSE during competition.

Post-exercise cold water immersion: effect on core temperature and melatonin responses.

To study the effect of post-exercise cold water immersion (CWI) on core temperature and melatonin responses, 10 male cyclists completed two evening (~1800 hours) cycling trials followed by a 15-min CWI (14 °C) or warm water immersion (WWI; 34 °C), and were then monitored for 90 min post-immersion. The exercise trial involved 15 min at 75 % peak power, followed by a 15 min time trial. Core (rectal) temperature was not different between the two conditions pre-exercise (~37.4 °C), post-exercise (~39 °C) or immediately post-immersion (~37.7 °C), but was significantly (p < 0.05) below pre-exercise levels at 60 and 90 min post-immersion in both conditions. Core temperature was significantly lower after CWI than WWI at 30 min (36.84 ± 0.24 vs. 37.42 ± 0.40 °C, p < 0.05) and 90 min (36.64 ± 0.24 vs. 36.95 ± 0.43 °C, p < 0.05) post-immersion. Salivary melatonin levels significantly increased (p < 0.05) from post-exercise (~5 pM) to 90 min post-immersion (~8.3 pM), but were not different between conditions. At 30 and 90 min post-immersion heart rate was significantly lower (~5-10 bpm, p < 0.01) after CWI than WWI. These results show that undertaking either CWI or WWI post-exercise in the evening lowers core temperature below baseline for at least 90 min; however, the magnitude of decrease is significantly greater following CWI. The usual evening increase in melatonin is unaffected by exercise or post-exercise water immersion undertaken between ~1800 and ~2000 hours.

Differences in spinopelvic kinematics in sweep and scull ergometer rowing.

OBJECTIVE: The spinopelvic kinematics of sweep and scull have yet to be investigated, despite evidence suggesting that sweep rowing may be provocative for low back pain (LBP). The aim of this study was to determine whether differences existed in spinopelvic kinematics in high-level rowers without LBP in sweep and scull ergometer rowing. DESIGN: Repeated measures study. SETTING: Institute of Sport Laboratory. PARTICIPANTS: Ten high-level rowers. INTERVENTIONS: Kinematics of the pelvis, lower lumbar, upper lumbar, and lower thoracic regions during the drive phase of the rowing stroke were measured while rowing on an interchangeable sweep/scull ergometer. MAIN OUTCOME MEASURES: Total and segmental spinopelvic kinematics. RESULTS: Sweep rowing showed greater lateral bend (P < 0.05) throughout the stroke, which was predominately due to movement of the upper lumbar and lower thoracic regions. Furthermore, sweep rowing displayed a greater magnitude (P < 0.05) of axial rotation at the catch (created at the pelvis). Both sweep and scull rowing showed values close to end range flexion for the lower lumbar spine at the catch and early drive phases. No difference (P > 0.05) was evident in lateral bend or axial rotation values for the lower lumbar region. CONCLUSIONS: Some differences exist in spinopelvic kinematics between sweep and scull ergometer rowing. However, it may be speculated that the lack of differences in lateral bend and axial rotation at the lower lumbar spine in sweep rowing may represent an adaptive and protective approach of experienced rowers. This may be the focus of future research studies.

Relationship between inflammatory cytokines and self-report measures of training overload.

It has been purported that inflammatory cytokines may be responsible for the aetiology of overtraining. The aim of the present study was to investigate the relationship between self-reported measures of overtraining and inflammatory cytokines. Eight elite male rowers were monitored in their natural training environment for 8 weeks prior to the 2007 Rowing World Championships. During this period of intense endurance training, self-report measures of overtraining and inflammatory cytokines (Interleukin (IL)-1beta, IL-6, IL-8, IL-10, IL-12p70, and Tumor Necrosis Factor (TNF)-alpha) were assessed fortnightly. Consistent with previous findings, proinflammatory cytokines IL-1beta and TNF-alpha were significantly associated (p

Examining the decay in serum ferritin following intravenous iron infusion: a retrospective cohort analysis of Olympic sport female athletes.

The long-term decay rate of serum ferritin post-iron infusion in athletic populations is currently unknown. Here, we modelled the decay rate of serum ferritin in female athletes after an intravenous iron infusion (n = 22). The post-infusion serum ferritin response and the rate of decay was highly variable between athletes; however, we demonstrate that follow-up blood testing at 1 (154 µg/L; 77-300 µg/L) and 6 months (107 µg/L; 54-208 µg/L) post-infusion is appropriate to observe treatment efficacy and effectiveness. Novelty Female athletes should have serum ferritin assessed at 1 and 6 months following an intravenous iron infusion to determine efficacy and effectiveness.

Medication information and supply behaviours in elite and developing athletes.

OBJECTIVES: To investigate the behaviours of elite and developing athletes in obtaining medications and medication information, and to identify the role of pharmacists in athlete care. DESIGN: Cross-sectional survey. METHODS: An electronic, 39-item questionnaire was developed, piloted and distributed to elite and developing athletes aged 18 years and above at a state-based sporting institute. Quantitative data was analysed using descriptive statistics and free text comments were analysed using an inductive reasoning approach. RESULTS: A total of 98 responses were analysed. Ninety (n=90/98, 91.84%) participants obtained medications in the six months prior to survey completion. Pharmacies were the most common source of both prescription (n=67/69, 97.10%) and non-prescription medications (n=64/75, 85.33%). Forty-five (n=45/98, 45.92%) participants also attended pharmacies when they had a minor ailment. Sixty-two (n=62/98, 63.27%) participants 'sometimes' consulted pharmacists for medication information. Only 11 (n=11/98, 11.22%) knew, according to their sporting institute medication policy, that athletes were required to consult a medical practitioner before taking anti-inflammatory, pain-relieving or sleep-inducing medications. Forty (n=40/98, 40.82%) participants believed pharmacists could play a role in their medication management. CONCLUSIONS: Many elite and developing athletes visited pharmacies for medication supply and treatment of minor ailments. Doping regulatory agency websites were the most commonly used and trusted sources for medication information, although some athletes believed pharmacists could also contribute to their medication management. Future research should consider whether pharmacists are ready for a role in sports pharmacy.

Cumulative effects of consecutive running sessions on hemolysis, inflammation and hepcidin activity.

The effect of two running sessions completed within a 12-h period on hemolysis, inflammation, and hepcidin activity in endurance athletes was investigated. Ten males completed two experimental trials in a randomized, counterbalanced order. The two trials included (a) a one-running-session trial (T1) including 10 x 1 km interval repeats (90% peak VO2 velocity), and (b) a two-running-session trial (T2), comprising a continuous 10-km run (70% peak VO2 velocity), and a 10 x 1 km interval run (90% peak VO2 velocity) completed 12 h later. Interleukin-6 (IL-6), free hemoglobin (Hb), haptoglobin (Hp), iron, ferritin, and hepcidin were assessed post-exercise. After the T1 and T2 interval runs, free Hb was significantly increased and Hp significantly decreased (p

Effect of water immersion methods on post-exercise recovery from simulated team sport exercise.

This study aimed to compare the efficacy of hot/cold contrast water immersion (CWI), cold-water immersion (COLD) and no recovery treatment (control) as post-exercise recovery methods following exhaustive simulated team sports exercise. Repeated sprint ability, strength, muscle soreness and inflammatory markers were measured across the 48-h post-exercise period. Eleven male team-sport athletes completed three 3-day testing trials, each separated by 2 weeks. On day 1, baseline measures of performance (10 m x 20 m sprints and isometric strength of quadriceps, hamstrings and hip flexors) were recorded. Participants then performed 80 min of simulated team sports exercise followed by a 20-m shuttle run test to exhaustion. Upon completion of the exercise, and 24h later, participants performed one of the post-exercise recovery procedures for 15 min. At 48 h post-exercise, the performance tests were repeated. Blood samples and muscle soreness ratings were taken before and immediately after post-exercise, and at 24h and 48 h post-exercise. In comparison to the control and CWI treatments, COLD resulted in significantly lower (p<0.05) muscle soreness ratings, as well as in reduced decrements to isometric leg extension and flexion strength in the 48-h post-exercise period. COLD also facilitated a more rapid return to baseline repeated sprint performances. The only benefit of CWI over control was a significant reduction in muscle soreness 24h post-exercise. This study demonstrated that COLD following exhaustive simulated team sports exercise offers greater recovery benefits than CWI or control treatments.

Effect of postexercise recovery procedures following strenuous stair-climb running.

This study compared the effects of hot/cold water immersion, static stretching, and no recovery (control) interventions on leg strength, rowing performance, and indicators of muscle soreness/damage in the 72 hours following strenuous stair-climb running. Club (n = 14) and elite (Sports Institute) (n = 6) rowers performed the training run on three separate occasions. After each run, participants completed a randomly assigned 15-minute recovery treatment, either hot/cold, static stretching, or control, which were repeated at 24 and 48 hours postrun. No significant strength or performance differences existed between the three recovery treatments for either group. Muscle soreness for both groups remained significantly elevated (p < 0.05) above baseline at 72 hours postrun. At 48-hours postrun serum creatine kinase levels had returned to baseline and at 72 hours postrun were below baseline in both groups. In conclusion, neither hot/cold nor static stretching accelerated recovery at 72 hours beyond that achieved by the control condition.

Impact of training on changes in perceived stress and cytokine production.

Data on training of competitive athletes and the inflammatory response, and, more specifically, the utility of psychological inventories to monitor this response in regards to overreaching is limited. The aim of the present study was to investigate the association of the Perceived Stress Scale (PSS) and inflammatory markers in elite rowers. Eight rowers (males n = 4; females n = 4) were monitored over an 8-week training period, comprising 12 sessions each week and training an average 3.11 h.d(-1). Training volume was periodized weekly while intensity was maintained throughout the study. Perceived stress was measured weekly pretraining, and capillary blood samples (500 microL) were taken post-training. Significant associations between perceived stress and cytokines interleukin-6 (p < .05) and tumor necrosis factor alpha (p < .05) were observed. While further investigation of the role of cytokines in the overtraining process is required, these data provide preliminary support for an association between perceived stress and the inflammatory responses to training.

The Impact of Morning versus Afternoon Exercise on Iron Absorption in Athletes.

PURPOSE: This study examined postexercise inflammatory, hepcidin, and iron absorption responses to endurance exercise performed in the morning versus the afternoon. METHODS: Sixteen endurance-trained runners (10 male, 6 female) with serum ferritin (sFer) < 50 µg·L completed a 90-min running protocol (65% vV˙O2max) in the morning (AM), or the afternoon (PM), in a crossover design. An iron-fortified fluid labeled with stable iron isotopes (Fe or Fe) was administered with a standardized meal 30 min following the exercise and control conditions during each trial, serving as a breakfast and dinner meal. Venous blood samples were collected before, immediately after, and 3 h after the exercise and control conditions to measure sFer, serum interleukin-6 (IL-6), and serum hepcidin-25. A final venous blood sample was collected 14 d after each trial to determine the erythrocyte iron incorporation, which was used to calculate iron absorption. Linear mixed-modeling was used to analyze the data. RESULTS: Overall, exercise significantly increased the concentrations of IL-6 (4.938 pg·mL; P = 0.006), and hepcidin-25 concentrations significantly increased 3 h after exercise by 0.380 nM (P < 0.001). During the PM trial, hepcidin concentrations exhibited diurnal tendency, increasing 0.55 nM at rest (P = 0.007), before further increasing 0.68 nM (P < 0.001) from prerun to 3 h postrun. Fractional iron absorption was significantly greater at breakfast after the AM run, compared with both the rested condition (0.778%; P = 0.020) and dinner in the AM run trial (0.672%; P = 0.011). CONCLUSIONS: Although exercise resulted in increased concentrations of IL-6 and hepcidin, iron was best absorbed in the morning after exercise, indicating there may be a transient mechanism during the acute postexercise window to promote iron absorption opposing the homeostatic regulation by serum hepcidin elevations.

The relationship between the VO2 slow component, muscle metabolites and performance during very-heavy exhaustive exercise.

This study examined the relationship between the V O(2) response, particularly the slow component (SC), muscle metabolite changes and performance during very-heavy exhaustive exercise. Sixteen active females performed a graded exercise test to determine V O(2peak) and the lactate threshold followed 48h later by a constant-load cycle test to exhaustion (ET) at 85% V O(2peak) intensity. Muscle biopsies and capillary blood samples were obtained before and after the ET to determine changes in muscle ATP, pH, lactate and phosphocreatine and also plasma pH and lactate. Breath-by-breath data from the ET were smoothed using 5-s averages and fit to a three-component exponential model. The mean time to exhaustion (t(exh)) during the ET was 16.8 (+/-6.4) min. Results showed no correlation between the SC and t(exh) or any muscle metabolite changes (p>0.05). Significant correlations (p<0.05) were evident between t(exh) and tau; tau(0) (r=-0.54), tau(1) (r=-0.65), change in (Delta) pH(b) (r=-0.60), Delta[La(-)](b) (r=-0.58) and [La(-)](b post) (r=-0.64). Significant correlations (p<0.05) were also evident between tau(1) and [La(-)](b post) (r=0.54). Furthermore, a negative value resulted when the accumulated oxygen deficit was calculated for the entire duration of the ET. Results showed no association between the amplitude of the SC and t(ext) or to changes in muscle/blood metabolites, suggesting that the SC is not a determinant of high-intensity exercise tolerance. Furthermore, it is possible that a reduced perturbation of anaerobic energy sources, as a result of a faster tau(1), may have contributed to a longer t(exh).

Selected physical capacity norms for Australian football players at the non-elite level.

Australian football is a popular male team sport that consists mainly of participants competing at the non-elite level. The main purpose of this study was to compare in non-elite Australian football players competing in sub-elite and community leagues, selected physical capacities recognised as predictors of lower extremity injury in Australian football and/or other sports. Participants were 143 adult (mean age of 22.2 years) male Western Australian footballers from the Western Australian Football League (WAFL) (sub-elite) and the Western Australian Amateur Football League (WAAFL) (community). During the 2005 regular playing season participants completed a questionnaire and a physical measurement testing session. The physical testing session involved the following lower extremity measures: generalised joint laxity, leg length discrepancy, presence of Morton's toe, foot arch, hamstring flexibility and static balance. Football players from the sub-elite and community leagues did not differ significantly in any of the physical testing session measures or in the questionnaire items relating to injury number in the past 12 months and lower limb preventative device use. However, they did differ in some measures with players from the sub-elite league significantly more likely to stretch after a match and training, and to have a designated stretching leader at their club. While players from the community league were significantly more likely to smoke and to participate in sports additional to Australian football. Although the selected physical capacities did not differ between the sub-elite and community players in this study, future research should be aimed at identifying differences for a greater number of physical capacities, including skill and endurance, while utilising a larger sample.

Effects of chronic NaHCO3 ingestion during interval training on changes to muscle buffer capacity, metabolism, and short-term endurance performance.

This study determined the effects of altering the H(+) concentration during interval training, by ingesting NaHCO(3) (Alk-T) or a placebo (Pla-T), on changes in muscle buffer capacity (beta m), endurance performance, and muscle metabolites. Pre- and posttraining peak O(2) uptake (V(O2 peak)), lactate threshold (LT), and time to fatigue at 100% pretraining V(O2 peak) intensity were assessed in 16 recreationally active women. Subjects were matched on the LT, were randomly placed into the Alk-T (n = 8) or Pla-T (n = 8) groups, and performed 8 wk (3 days/wk) of six to twelve 2-min cycle intervals at 140-170% of their LT, ingesting NaHCO(3) or a placebo before each training session (work matched between groups). Both groups had improvements in beta m (19 vs. 9%; P < 0.05) and V(O2 peak) (22 vs. 17%; P < 0.05) after the training period, with no differences between groups. There was a significant correlation between pretraining beta m and percent change in beta m (r = -0.70, P < 0.05). There were greater improvements in both the LT (26 vs. 15%; P = 0.05) and time to fatigue (164 vs. 123%; P = 0.05) after Alk-T, compared with Pla-T. There were no changes to pre- or postexercise ATP, phosphocreatine, creatine, and intracellular lactate concentrations, or pH(i) after training. Our findings suggest that training intensity, rather than the accumulation of H(+) during training, may be more important to improvements in beta m. The group ingesting NaHCO(3) before each training session had larger improvements in the LT and endurance performance, possibly because of a reduced metabolic acidosis during training and a greater improvement in muscle oxidative capacity.

Effects of resistance training on H+ regulation, buffer capacity, and repeated sprints.

PURPOSE: We investigated the effects of resistance training on muscle buffer capacity, H regulation, and repeated-sprint ability (RSA). METHODS: Sixteen recreationally active females performed a graded exercise test to determine VO2peak and the lactate threshold (LT), a repeated-sprint test (5 x 6 s, every 30 s) to determine RSA, and a 60-s high-intensity exercise test based on their pretraining RSA score (CIT60; continuous cycling at approximately 160% VO2peak). Muscle biopsies (vastus lateralis) were sampled before and immediately after CIT60. Subjects were then randomly assigned to either a high-repetition (three to five sets of 15-20 reps) short-rest (20 s) resistance-training group or to a control group. RESULTS: Training did not result in significant improvements in VO2peak (P > 0.05) but did improve the LT, leg strength, and RSA (P < 0.05). There were no significant improvements in muscle buffer capacity after training (P > 0.05); however, there was a significant reduction in H in the muscle and blood after high-intensity exercise (CIT60) (P < 0.05), CONCLUSIONS: High-repetition, short-rest, resistance training does not improve muscle buffer capacity in active females, but it does reduce H accumulation during high-intensity exercise (approximately 160% VO2peak). It is likely that increases in strength, LT, and ion regulation contributed to the improved RSA.