Iron status and the acute post-exercise hepcidin response in athletes
- Peeling, Peter, Sim, Marc, Badenhorst, Claire, Dawson, Brian, Govus, Andrew, Abbiss, Chris, Swinkels, Dorine, Trinder, Debbie
- Authors: Peeling, Peter , Sim, Marc , Badenhorst, Claire , Dawson, Brian , Govus, Andrew , Abbiss, Chris , Swinkels, Dorine , Trinder, Debbie
- Date: 2014
- Type: Text , Journal article ,
- Relation: PLoS One Vol. 9, no. 3 (2014), p. e93002
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- Description: This study explored the relationship between serum ferritin and hepcidin in athletes. Baseline serum ferritin levels of 54 athletes from the control trial of five investigations conducted in our laboratory were considered; athletes were grouped according to values <30 mug/L (SF<30), 30-50 mug/L (SF30-50), 50-100 mug/L (SF50-100), or >100 mug/L (SF>100). Data pooling resulted in each athlete completing one of five running sessions: (1) 8 x 3 min at 85% vVO2peak; (2) 5 x 4 min at 90% vVO2peak; (3) 90 min continuous at 75% vVO2peak; (4) 40 min continuous at 75% vVO2peak; (5) 40 min continuous at 65% vVO2peak. Athletes from each running session were represented amongst all four groups; hence, the mean exercise duration and intensity were not different (p>0.05). Venous blood samples were collected pre-, post- and 3 h post-exercise, and were analysed for serum ferritin, iron, interleukin-6 (IL-6) and hepcidin-25. Baseline and post-exercise serum ferritin levels were different between groups (p<0.05). There were no group differences for pre- or post-exercise serum iron or IL-6 (p>0.05). Post-exercise IL-6 was significantly elevated compared to baseline within each group (p<0.05). Pre- and 3 h post-exercise hepcidin-25 was sequentially greater as the groups baseline serum ferritin levels increased (p<0.05). However, post-exercise hepcidin levels were only significantly elevated in three groups (SF30-50, SF50-100, and SF>100; p<0.05). An athlete's iron stores may dictate the baseline hepcidin levels and the magnitude of post-exercise hepcidin response. Low iron stores suppressed post-exercise hepcidin, seemingly overriding any inflammatory-driven increases.
- Authors: Peeling, Peter , Sim, Marc , Badenhorst, Claire , Dawson, Brian , Govus, Andrew , Abbiss, Chris , Swinkels, Dorine , Trinder, Debbie
- Date: 2014
- Type: Text , Journal article ,
- Relation: PLoS One Vol. 9, no. 3 (2014), p. e93002
- Full Text:
- Reviewed:
- Description: This study explored the relationship between serum ferritin and hepcidin in athletes. Baseline serum ferritin levels of 54 athletes from the control trial of five investigations conducted in our laboratory were considered; athletes were grouped according to values <30 mug/L (SF<30), 30-50 mug/L (SF30-50), 50-100 mug/L (SF50-100), or >100 mug/L (SF>100). Data pooling resulted in each athlete completing one of five running sessions: (1) 8 x 3 min at 85% vVO2peak; (2) 5 x 4 min at 90% vVO2peak; (3) 90 min continuous at 75% vVO2peak; (4) 40 min continuous at 75% vVO2peak; (5) 40 min continuous at 65% vVO2peak. Athletes from each running session were represented amongst all four groups; hence, the mean exercise duration and intensity were not different (p>0.05). Venous blood samples were collected pre-, post- and 3 h post-exercise, and were analysed for serum ferritin, iron, interleukin-6 (IL-6) and hepcidin-25. Baseline and post-exercise serum ferritin levels were different between groups (p<0.05). There were no group differences for pre- or post-exercise serum iron or IL-6 (p>0.05). Post-exercise IL-6 was significantly elevated compared to baseline within each group (p<0.05). Pre- and 3 h post-exercise hepcidin-25 was sequentially greater as the groups baseline serum ferritin levels increased (p<0.05). However, post-exercise hepcidin levels were only significantly elevated in three groups (SF30-50, SF50-100, and SF>100; p<0.05). An athlete's iron stores may dictate the baseline hepcidin levels and the magnitude of post-exercise hepcidin response. Low iron stores suppressed post-exercise hepcidin, seemingly overriding any inflammatory-driven increases.
A seven day running training period increases basal urinary hepcidin levels as compared to cycling
- Sim, Marc, Dawson, Brian, Landers, Grant, Swinkels, Dorine, Tjalsma, Harold, Wiegerinck, Erwin, Trinder, Debbie, Peeling, Peter
- Authors: Sim, Marc , Dawson, Brian , Landers, Grant , Swinkels, Dorine , Tjalsma, Harold , Wiegerinck, Erwin , Trinder, Debbie , Peeling, Peter
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of the International Society of Sports Nutrition Vol. 11, no. 1 (2014), p. 1-9
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- Description: BACKGROUND: This investigation compared the effects of an extended period of weight-bearing (running) vs. non-weight-bearing (cycling) exercise on hepcidin production and its implications for iron status. METHODS: Ten active males performed two separate exercise training blocks with either running (RTB) or cycling (CTB) as the exercise mode. Each block consisted of five training sessions (Day 1, 2, 4, 5, 6) performed over a seven day period that were matched for exercise intensity. Basal venous blood samples were obtained on Day 1 (D1), and on Recovery Days 3 (R3) and 7 (R7) to assess iron status, while basal and 3 h post-exercise urinary hepcidin levels were measured on D1, D2, D6, as well as R3 and R7 (basal levels only) for each condition. RESULTS: Basal urinary hepcidin levels were significantly elevated (p = 0.05) at D2, R3 and R7 as compared to D1 in RTB. Furthermore, 3 h post-exercise urinary hepcidin levels on D1 were also significantly higher in RTB compared to CTB (p = 0.05). In CTB, urinary hepcidin levels were not statistically different on D1 as compared to R7. Iron parameters were not significantly different at D1 compared to R3 and R7 during both conditions. CONCLUSIONS: These results suggest that basal hepcidin levels may increase over the course of an extended training program, especially if a weight-bearing exercise modality is undertaken. However, despite any variations in hepcidin production, serum iron parameters in both RTB and CTB were unaffected, possibly due to the short duration of each training block. In comparing running to cycling, non-weight-bearing activity may require more training sessions, or sessions of extended duration, before any significant changes in basal hepcidin levels appear. Chronic elevations in hepcidin levels may help to explain the high incidence of iron deficiency in athletes.
- Authors: Sim, Marc , Dawson, Brian , Landers, Grant , Swinkels, Dorine , Tjalsma, Harold , Wiegerinck, Erwin , Trinder, Debbie , Peeling, Peter
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of the International Society of Sports Nutrition Vol. 11, no. 1 (2014), p. 1-9
- Full Text:
- Reviewed:
- Description: BACKGROUND: This investigation compared the effects of an extended period of weight-bearing (running) vs. non-weight-bearing (cycling) exercise on hepcidin production and its implications for iron status. METHODS: Ten active males performed two separate exercise training blocks with either running (RTB) or cycling (CTB) as the exercise mode. Each block consisted of five training sessions (Day 1, 2, 4, 5, 6) performed over a seven day period that were matched for exercise intensity. Basal venous blood samples were obtained on Day 1 (D1), and on Recovery Days 3 (R3) and 7 (R7) to assess iron status, while basal and 3 h post-exercise urinary hepcidin levels were measured on D1, D2, D6, as well as R3 and R7 (basal levels only) for each condition. RESULTS: Basal urinary hepcidin levels were significantly elevated (p = 0.05) at D2, R3 and R7 as compared to D1 in RTB. Furthermore, 3 h post-exercise urinary hepcidin levels on D1 were also significantly higher in RTB compared to CTB (p = 0.05). In CTB, urinary hepcidin levels were not statistically different on D1 as compared to R7. Iron parameters were not significantly different at D1 compared to R3 and R7 during both conditions. CONCLUSIONS: These results suggest that basal hepcidin levels may increase over the course of an extended training program, especially if a weight-bearing exercise modality is undertaken. However, despite any variations in hepcidin production, serum iron parameters in both RTB and CTB were unaffected, possibly due to the short duration of each training block. In comparing running to cycling, non-weight-bearing activity may require more training sessions, or sessions of extended duration, before any significant changes in basal hepcidin levels appear. Chronic elevations in hepcidin levels may help to explain the high incidence of iron deficiency in athletes.
Effect of tart cherry juice on recovery and next day performance in well-trained Water Polo players
- McCormick, Rachel, Peeling, Peter, Binnie, Martyn, Dawson, Brian, Sim, Marc
- Authors: McCormick, Rachel , Peeling, Peter , Binnie, Martyn , Dawson, Brian , Sim, Marc
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of the International Society of Sports Nutrition Vol. 13, no. 1 (2016), p. 1-8
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- Description: Background: Tart Montmorency cherries contain high concentrations of phytochemicals and anthocyanins, which have recently been linked to improved athletic recovery and subsequent performance. To date however, previous work reporting promising results has focused on land-based endurance sports, with any potential benefits to team sports remaining unknown. As such, this investigation set-out to examine the effect of supplemental tart cherry juice (CJ) on recovery and next day athletic performance in highly-trained water-based team sport athletes over seven days. Methods: In a randomised, double-blind, repeated measures, crossover design, nine male Water Polo athletes were supplemented with CJ or a placebo equivalent (PLA) for six consecutive days. Prior to, and at the completion of the supplementation period, water-based performance testing was conducted. On day 6, participants also undertook a fatiguing simulated team game activity. Venous blood samples were collected (Pre-exercise: day 1, 6 and 7; Post-exercise: day 6) to investigate markers of inflammation [Interleukin-6 (IL-6); C-reactive protein (CRP)] and oxidative stress [Uric Acid (UA); F2-Isoprostane (F2-IsoP)]. A daily diary was also completed (total quality of recovery, delayed onset muscle soreness) as a measure of perceptual recovery. Results: In both conditions, day 6 post-exercise IL-6 was significantly higher than pre-exercise and day 7 (p<0.05); CRP was greater on day 7 as compared to day 6 pre- and post-exercise (p<0.05); F2-IsoP was significantly lower on day 7 as compared to day 1 and day 6 (p<0.05); UA remained unchanged (p>0.05). No differences were found for any performance or recovery measures. Conclusions: The lack of difference observed in the blood markers between groups may reflect the intermittent, non-weight bearing demands of Water Polo, with such activity possibly unable to create a substantial inflammatory response or oxidative stress (over 7 days) to impede performance; thereby negating any potential beneficial effects associated with CJ supplementation. Trial registration: This trial was registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR). Registration number: ACTRN12616001080415. Date registered: 11/08/2016, retrospectively registered. © 2016 The Author(s).
- Authors: McCormick, Rachel , Peeling, Peter , Binnie, Martyn , Dawson, Brian , Sim, Marc
- Date: 2016
- Type: Text , Journal article
- Relation: Journal of the International Society of Sports Nutrition Vol. 13, no. 1 (2016), p. 1-8
- Full Text:
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- Description: Background: Tart Montmorency cherries contain high concentrations of phytochemicals and anthocyanins, which have recently been linked to improved athletic recovery and subsequent performance. To date however, previous work reporting promising results has focused on land-based endurance sports, with any potential benefits to team sports remaining unknown. As such, this investigation set-out to examine the effect of supplemental tart cherry juice (CJ) on recovery and next day athletic performance in highly-trained water-based team sport athletes over seven days. Methods: In a randomised, double-blind, repeated measures, crossover design, nine male Water Polo athletes were supplemented with CJ or a placebo equivalent (PLA) for six consecutive days. Prior to, and at the completion of the supplementation period, water-based performance testing was conducted. On day 6, participants also undertook a fatiguing simulated team game activity. Venous blood samples were collected (Pre-exercise: day 1, 6 and 7; Post-exercise: day 6) to investigate markers of inflammation [Interleukin-6 (IL-6); C-reactive protein (CRP)] and oxidative stress [Uric Acid (UA); F2-Isoprostane (F2-IsoP)]. A daily diary was also completed (total quality of recovery, delayed onset muscle soreness) as a measure of perceptual recovery. Results: In both conditions, day 6 post-exercise IL-6 was significantly higher than pre-exercise and day 7 (p<0.05); CRP was greater on day 7 as compared to day 6 pre- and post-exercise (p<0.05); F2-IsoP was significantly lower on day 7 as compared to day 1 and day 6 (p<0.05); UA remained unchanged (p>0.05). No differences were found for any performance or recovery measures. Conclusions: The lack of difference observed in the blood markers between groups may reflect the intermittent, non-weight bearing demands of Water Polo, with such activity possibly unable to create a substantial inflammatory response or oxidative stress (over 7 days) to impede performance; thereby negating any potential beneficial effects associated with CJ supplementation. Trial registration: This trial was registered with the Australian and New Zealand Clinical Trials Registry (ANZCTR). Registration number: ACTRN12616001080415. Date registered: 11/08/2016, retrospectively registered. © 2016 The Author(s).
Association between preseason training and performance in elite Australian football
- McCaskie, Callum, Young, Warren, Fahrner, Brendan, Sim, Marc
- Authors: McCaskie, Callum , Young, Warren , Fahrner, Brendan , Sim, Marc
- Date: 2019
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 14, no. 1 (2019), p. 68-75
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- Description: Purpose: To examine the association between preseason training variables and subsequent in-season performance in an elite Australian football team. Methods: Data from 41 elite male Australian footballers (mean [SD] age = 23.4 [3.1] y, height =188.4 [7.1] cm, and mass = 86.7 [7.9] kg) were collected from 1 Australian Football League (AFL) club. Preseason training data (external load, internal load, fitness testing, and session participation) were collected across the 17-wk preseason phase (6 and 11 wk post-Christmas). Champion Data© Player Rank (CDPR), coaches’ ratings, and round 1 selection were used as in-season performance measures. CDPR and coaches’ ratings were examined over the entire season, first half of the season, and the first 4 games. Both Pearson and partial (controlling for AFL age) correlations were calculated to assess if any associations existed between preseason training variables and in-season performance measures. A median split was also employed to differentiate between higher- and lower-performing players for each performance measure. Results: Preseason training activities appeared to have almost no association with performance measured across the entire season and the first half of the season. However, many preseason training variables were significantly linked with performance measured across the first 4 games. Preseason training variables that were measured post-Christmas were the most strongly associated with in-season performance measures. Specifically, total on-field session rating of perceived exertion post-Christmas, a measurement of internal load, displayed the greatest association with performance. Conclusion: Late preseason training (especially on-field match-specific training) is associated with better performance in the early season.
- Authors: McCaskie, Callum , Young, Warren , Fahrner, Brendan , Sim, Marc
- Date: 2019
- Type: Text , Journal article
- Relation: International Journal of Sports Physiology and Performance Vol. 14, no. 1 (2019), p. 68-75
- Full Text:
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- Description: Purpose: To examine the association between preseason training variables and subsequent in-season performance in an elite Australian football team. Methods: Data from 41 elite male Australian footballers (mean [SD] age = 23.4 [3.1] y, height =188.4 [7.1] cm, and mass = 86.7 [7.9] kg) were collected from 1 Australian Football League (AFL) club. Preseason training data (external load, internal load, fitness testing, and session participation) were collected across the 17-wk preseason phase (6 and 11 wk post-Christmas). Champion Data© Player Rank (CDPR), coaches’ ratings, and round 1 selection were used as in-season performance measures. CDPR and coaches’ ratings were examined over the entire season, first half of the season, and the first 4 games. Both Pearson and partial (controlling for AFL age) correlations were calculated to assess if any associations existed between preseason training variables and in-season performance measures. A median split was also employed to differentiate between higher- and lower-performing players for each performance measure. Results: Preseason training activities appeared to have almost no association with performance measured across the entire season and the first half of the season. However, many preseason training variables were significantly linked with performance measured across the first 4 games. Preseason training variables that were measured post-Christmas were the most strongly associated with in-season performance measures. Specifically, total on-field session rating of perceived exertion post-Christmas, a measurement of internal load, displayed the greatest association with performance. Conclusion: Late preseason training (especially on-field match-specific training) is associated with better performance in the early season.
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