Including arm exercise during a cold water immersion recovery better assists restoration of sprint cycling performance.

Sprint (high-intensity) exercise performance is reduced when immediately preceded by cold water immersion (CWI). We aimed to investigate whether this performance effect could be attenuated by combining an active recovery (arm exercise) with hip-level CWI, and whether this attenuation may be related to an effect on core temperature (Tcore ). Participants (n = 8) completed three Wingate tests before (Ex1) and after (Ex2) four different 30-min recovery interventions: CWI at 15 °C (CW15), arm exercise during CWI at 15 °C (CW15+AE), arm exercise during thermoneutral immersion at 34 °C (TW34+AE) and non-immersed arm exercise (AE). After AE and TW34+AE, performance during Ex2 was not different from Ex1; while after CW15+AE and CW15, performance was reduced by 4.9% and 7.6%, respectively. Arm exercise maintained Tcore during recovery in CW15+AE, while it declined to a larger extent upon commencement of Ex2 (-0.9 °C) when compared with CW15 (-0.6 °C). This suggests similar leg muscle cooling during recovery in CW15 and CW15+AE. Without any other significant effects (e.g., on blood lactate), these data suggest that the improvement in sprint performance following an active CWI recovery, over CWI alone, may be related to maintained Tcore and its effect on neurophysiological mechanisms that drive muscle activation, but not by reduced muscle cooling.

12 weeks of simulated barefoot running changes foot-strike patterns in female runners.

To investigate the effect of a transition program of simulated barefoot running (SBR) on running kinematics and foot-strike patterns, female recreational athletes (n=9, age 29 ± 3 yrs) without SBR experience gradually increased running distance in Vibram FiveFingers SBR footwear over 12 weeks. Matched controls (n=10, age 30 ± 4 yrs) continued running in standard footwear. A 3-D motion analysis of treadmill running at 12 km/h(-1) was performed by both groups, barefoot and shod, pre- and post-intervention. Post-intervention data indicated a more-forefoot strike pattern in the SBR group compared to controls; both running barefoot (P>0.05), and shod (P<0.001). When assessed barefoot, there were significant kinematic differences across time in the SBR group for ankle flexion angle at toe-off (P<0.01). When assessed shod, significant kinematic changes occurred across time, for ankle flexion angles at foot-strike (P<0.001) and toe-off (P<0.01), and for range of motion (ROM) in the absorptive phase of stance (P<0.01). A knee effect was recorded in the SBR group for flexion ROM in the absorptive phase of stance (P<0.05). No significant changes occurred in controls. Therefore, a 12-week transition program in SBR could assist athletes seeking a more-forefoot strike pattern and "barefoot" kinematics, regardless of preferred footwear.

Effects of an eight week military training program on aerobic indices and psychomotor function.

This study assessed the effects of eight weeks of military training on aerobic fitness indices, military skills and neuropsychological function. Thirty five (n = 35) male Irish Defence Forces personnel, divided into training (n = 20) and control (n = 15) subgroups, completed tests of military aptitude (Kim's games, judging distance, fire order, map reading, weapon assembly) and neuropsychological function (Symbol digit modalities test (SDMT), Trail making test, Stroop test and grooved pegboard test) pre- and post-intervention. The repeated measures study design sought to account for any learning effect. Participants also completed a 10km route march, a two mile run and three by 20m shuttle run tests at both time points to quantify changes in fitness variables. The training sub-group significantly (P < 0.001) improved mean 20m shuttle-run distance and consequently estimated VO2 max pre- to post-intervention (49.8 +/- 1.0 vs. 52.4 +/- 0.9 mL x kg x min(-1)). Two mile run time was not significantly improved. Mean %HRmax during the 10km route march was significantly higher in both training (P < 0.001) and control (P < 0.01) sub-groups post-intervention (71 +/- 1 and 83 +/- 1%) compared to pre-intervention (65 +/- 1 and 77 +/- 1%). However, the training sub-group conducted the route march at a significantly faster speed on the second occasion. Military training significantly improved performance in 3/18 neuropsychological test components and 2/12 military skills test components. Training significantly improved ability to estimate both short (error; 36 +/- 6 vs. 12 +/- 1%) and intermediate (error; 72 +/- 12 vs. 11 +/- 3%) distances post-intervention. The training sub-group significantly (P < 0.01) improved SDMT score and mean Trail 1 time pre- to post-intervention (58.0 +/- 2.8 vs. 69.5 +/- 3.4; 18.1 +/- 0.8 vs. 14.4 +/- 0.8s, respectively). In Part 3 of the Stroop test, time mediated a significant (P < 0.05) and selective improvement in the training sub-group (51.3 +/- 3.2 vs. 63.8 +/- 5.4). In conclusion, aerobic fitness and a minority of neuropsychological and military skills tests improved following 8 weeks of military training.

Physiological changes following a 12 week gym based stair-climbing, elliptical trainer and treadmill running program in females.

AIM: Despite the growing popularity in recent years of the elliptical trainer aerobic exercise modality the physiological changes induced following a training program using elliptical trainers remains unknown. The present study investigated the metabolic and cardiorespiratory improvements following a 12-week aerobic training program using elliptical trainer, treadmill or stair-climbing modalities. METHODS: Twenty-two moderately active females (28.6 +/- 5.3 y, 1.65 +/- 0.05 m) were randomly assigned to treadmill running (n=7), elliptical trainer (n=8) or stair-climber (n=7) groups and trained 3 days x week(-1) initially at 70-80% of maximum heart rate (HRmax) for 30 min, progressing to 80-90% HRmax for 40 min. Subjects performed incremental exercise to volitional exhaustion using an electronically loaded cycle ergometer before and upon completion of the program. In addition, subjects performed sub-maximal fixed load tests at 0, 4, 8 and 12 weeks, using ergometers specific to their exercise group. RESULTS: No significant inter-group differences were recorded for pre-training VO2max or VEmax. Significant (p<0.05) post-training increases in cycling VO2max and VEmax were observed for treadmill (mean +/- SEM, 40.7 +/- 2.2 vs 43.4 +/- 2.6 ml x kg(-1) x min(-1) and 82.9 +/- 5.1 vs 90.2 +/- 6.4 l x min(-1)), elliptical trainer (36.9 +/- 2.5 vs 39.6 +/- 2.4 ml x kg(-1) x min(-1) and 86.8 +/- 2.3 vs 92.5 +/- 4.1 l x min(-1)) and stair-climber (37.4 +/- 2.9 vs 39.2 +/- 3.1 ml x kg(-1) x min(-1) and 95.9 +/- 5.8 vs 97.4 +/- 5.8 l x min(-1)) modalities, however, the increases were not significantly different between groups. For all groups, sub-maximal HR significantly decreased from week 0 to 4, and from week 4 to 8. CONCLUSION: In moderately active females similar physiological improvements were observed using stair-climber, elliptical trainer and treadmill running when training volume and intensity were equivalent.

Prevalence of obstructive airflow limitation in Irish collegiate athletes.

BACKGROUND: Asthma prevalence in athletes is variable, depending on the sport and training conditions. AIMS: To investigate the prevalence of obstructive airflow limitation, asthma control and lung volume differences in a control group and five groups of collegiate athletes--outdoor field, indoor court, endurance, combat sports and swimming. METHODS: Three hundred and five athletes completed a respiratory questionnaire and performed spirometry during normal training conditions, to determine FEV1, FVC and PEFR pre- and at 5, 10 and 15 minutes post-exercise. Between and within group analysis was carried out using single factor and repeated measures ANOVA. RESULTS: Previous diagnosis of asthma was reported by 24%, outdoor field sports 4.9%, indoor court sports 2.3%, endurance events 2.6%, combat sports 3%, swimming 6.9% and controls 4.3%. Mean FEV1 and FVC data, expressed as percentage of predicted, were greatest in swimming and lowest in controls. Swimming showed a significant rise in FEV1 post-exercise, indoor court and endurance sports demonstrated no change and outdoor field, combat and control groups showed a fall in FEV1 post-exercise. CONCLUSION: Warm humid training conditions appear protective against exercise-induced asthma. The greatest reductions in lung volumes occurred following high intensity exercise under cool conditions in the poorly aerobically conditioned.

Effect of recovery interventions on lactate removal and subsequent performance.

The recovery process in sport plays an essential role in determining subsequent athletic performance. This study investigated the effectiveness of different recovery interventions after maximal exercise. Eighteen trained male cyclists initially undertook an incremental test to determine maximal oxygen consumption. The four recovery interventions tested were: passive, active (50% maximal oxygen uptake), massage, and combined (involving active and massage components). All test sessions were separated by 2 to 3 days. During intervention trials subjects performed two simulated 5 km maximal effort cycling tests (T1 and T2) separated by a 20 min recovery. Performance time for the tests (t1, t2); blood lactate (BLa) during T1, T2, and every 3 min during recovery; and heart rate (HR) during the recovery intervention and T2 were recorded. Combined recovery was found to be better than passive (P<0.01) and either active or massage (P<0.05) in maintenance of performance time during T2. Active recovery was the most effective intervention for removing BLa at minutes 9 and 12, BLa removal during combined recovery was significantly better than passive at minute 3, and significantly better than passive, active, and massage at minute 15. In conclusion, combined recovery was the most efficient intervention for maintaining maximal performance time during T2, and active recovery was the best intervention for removing BLa.

A comparison of physiological responses to rowing on friction-loaded and air-braked ergometers.

The physiological responses of 10 trained rowers to a progressive incremental rowing protocol to exhaustion were investigated on Gjessing, Rowperfect fixed-mechanism and Rowperfect free-mechanism rowing ergometers. Heart rate, oxygen uptake (VO2), ventilation (VE) and blood lactate were determined at matched power values for each ergometer. The mean power and heart rate at the lactate anaerobic threshold were determined by graphical interpolation of data for each ergometer. Analysis of variance and linear regression showed differing responses at matched power and an approximate 40-50 W difference in power at the lactate anaerobic threshold when comparing the friction-loaded Gjessing with the air-braked Rowperfect fixed and Rowperfect free ergometers (P<0.01). No significant differences were noted when comparing the air-braked Rowperfect fixed and Rowperfect free ergometers. However, comparisons of VO2, VE and blood lactate at given heart rates and of heart rate at the lactate anaerobic threshold showed no significant differences between ergometers. Our results indicate similar physiological profiles for all ergometers tested when compared at equivalent heart rates, but differences when compared at matched power. A direct comparison of the data from Gjessing (friction-loaded) with Rowperfect fixed and Rowperfect free (air-braked) ergometers would therefore require a correction factor for inter-ergometer variation in displayed power data.

Anatomy of the proximal musculotendinous junction of the adductor longus muscle.

Injuries to the adductor longus commonly occur in the proximal part of the muscle tendon unit, close to the insertion site on the pubic bone. Ultrasonography, magnetic resonance imaging (MRI) and surgery have been helpful in localising the lesions, but the exact anatomy of the musculotendinous junction (MTJ) and insertion of the muscle remain unclear. We studied the anatomical features of the MTJ and measured the dimensions of the tendinous insertion into the pubic bone on 37 cadavers: 18 men and 19 women. The medial boundaries were the longest part of the tendon bilaterally in women, while the lateral aspect of the left muscle was greater in men. Tendinous fibres were predominantly found on the anterior surface, while the posterior surface consisted mainly of muscle tissue. The MTJ was clearly demarcated. There were several types of anomalies present which partially explains the difficulty in localising the site of injury and highlights the importance of individualized treatment.

Effect of variation in seat tube angle at different seat heights on submaximal cycling performance in man.

The effect of seat tube angle at selected seat heights (96, 100 and 104% trochanteric height) on heart rate, VO2 and lower limb kinematics was evaluated in 14 competitive male road racing cyclists during discontinuous submaximal exercise (200 W) on an air-resistance ergometer at seat tube angles of 68, 74 and 80 degrees. The tests were randomized to complete the nine combinations (three seat heights, three tube angles) in opposite directions from a starting tube angle of 74 degrees and 100% trochanteric height to avoid any time or sequence bias. Power efficiency was calculated for each combination from work done and VO2. All results were analysed using ANOVA for repeated measures. At a seat tube angle of 80 degrees, mean VO2 was significantly lower and power efficiency significantly higher compared with an angle of 74 degrees at all three seat heights, while heart rate was significantly lower only at a seat height equal to trochanteric height. At a seat tube angle of 74 degrees, mean VO2 and heart rate were significantly lower and power efficiency significantly higher compared with an angle of 68 degrees at all three seat heights. Hip range of movement and maximum and minimum hip angle were significantly less at an angle of 80 degrees compared with 68 degrees. Further biomechanical analysis suggested that the improvement in cycling efficiency observed at steeper seat tube angles was produced in part by the resultant altered ankling pattern of the cyclist.

Bone density profiles and osteoporosis incidence in Irish females.

1725 Irish females aged 15-70+ were included in this analysis to establish the group bone mineral density (BMD) profiles. Each subject was screened for 27 risk factors by questionnaire. Subjects were segregated into normal (N) and non-normal (NN) subgroups on the basis of the questionnaire. BMD of lumbar spine and hip were measured by dual energy X ray absorptiometry (DEXA). A substantial difference in BMD at all sites was observed between subgroups even following adjustment for body mass index and years of exposure to oestrogen. In the subgroup designated as non-normal 42%, 54%, 72% and 69% of those studied had spinal BMD levels > 2SD below mean peak at 55-59, 60-64, 65-69 and 70+ respectively. In comparison, similar age cohorts in the subgroup designated normal were 26%, 46%, 44% and 68% respectively. A marked difference was also observed in the younger age groups (15-34) where the percentage of individuals with spinal BMD levels > 2SD below mean peak was < 1.9% for N and 18.8% for NN. The results of this study suggest that the use of a questionnaire may be a valuable low cost screening tool in the younger groups.

Safety and efficacy of increasing wintertime vitamin D and calcium intake by milk fortification.

We studied the safety and efficacy of milk fortified with vitamin D3 and calcium. Over the winter, we conducted a double-blind, placebo-controlled trial of fortified milk (12 micrograms vitamin D3 and 1525 mg calcium per litre) compared to unfortified milk (0.3 micrograms vitamin D3 and 1270 mg calcium per litre) in 102 adults (aged 17-54 years). Serum 25-hydroxyvitamin D [25(OH)D], ionized calcium, and creatinine were measured at baseline and after intervention. Fortification reduced the seasonal decline in serum 25(OH)D concentrations by > 50%. In the fortified group, serum 25(OH)D decreased by 15 nmol/l from 77 +/- 35 nmol/l to 62 +/- 26 nmol/l (p < 0.001). In the control group, serum 25(OH)D fell by 31 nmol/l from 85 +/- 38 nmol/l to 54 +/- 25 nmol/l (p < 0.001). We suggest that milk enriched with vitamin D be provided in high-latitude European countries to diminish the wintertime fall in serum 25(OH)D.

Relationship between torque and EMG activity of a knee extensor muscle during isokinetic concentric and eccentric actions.

Integrated surface electromyographic (IEMG) activity of the vastus lateralis portion of the quadriceps muscle and knee torque were recorded during isokinetic concentric and eccentric actions, performed at maximum effort at a fixed velocity of 30 degrees s(-1) through 80-20 degrees knee flexion in 15 trained athletes. Mean IEMG and torque data were calculated for three ranges, viz. outer (25-44 degrees ), mid (45-54 degrees ) and inner (55-74 degrees ) and normalized as a percentage of mid-range concentric values. No significant difference was seen in IEMG activity either between left and right muscle or between concentric and eccentric action at any joint angle range. Similarly no significant difference was seen in torque between left and right muscle at any joint angle range. However, there was a significant difference in knee torque between the three angular ranges and between concentric and eccentric actions. It is concluded that no fixed relationship exists between vastus lateralis IEMG and quadriceps torque during maximum concentric and eccentric actions.