EXERCISE INTENSITY AND PACING STRATEGY OF A 5-KM INDOOR RACE WALK DURING A WORLD RECORD ATTEMPT: A CASE STUDY

The aim of this case study was to describe the physiological and regulatory processes, by means of heart rate (HR) monitoring and pacing strategy, in a top-level race walker (age: 32 years; height: 1.76 m; body mass: 62 kg; training volume: 130\u2013150 km\u2022wk-1) who was focused on the attainment of the 5-km indoor race walk (RW) World Record. The HRmean was 185 6 14.9 b\u2022min-1, with an HRmean/HRmax ratio of 0.96. Almost the whole race (91.8%) was performed to an intensity 6590% of the HRmax; lower intensity work was negligible (8.1%). The race profile was a reverse J-shaped pacing curve; in fact, the athlete completed the first 1,000 m in the fastest time, slowing during the middle 3,000 m, and increasing the speed during the final 1,000 m of the race. Despite the attempt failed (the athlete performed only the 2009 World leading performance, 18 minutes 23 seconds 47 tenths), these data suggest that a more linear strain distribution for the entire performance would be optimal instead of a fast-start strategy, which leads to a drastic decrement of the walking velocity. Moreover, this study supports the use of HR monitoring combined with the regulation of the effort to understand the physiological and regulatory processes during an indoor RW event

Physiological and physical profile of snowboarding: A preliminary review

The sport of snowboarding has grown in popularity as both a recreational winter activity as well as a prominent Olympic sport. Both forms are comprised of one of three different disciplines within the sport: freestyle, alpine, and snowboard-cross. In recent years, the increased professionalism and substantial growth of snowboarding as a global sport has increasingly attracted the interest of exercise physiologists and sport scientists. Given the small (but growing) number of studies that have been published, the research analyzing the physiological and performance characteristics and requirements of snowboarding remains limited. The absence of such studies signifies a lack of examination into this important but under-explored area of research, which could contribute valuable information to the scientific community and international snowboarding teams. The studies conducted thus far have indicated different requirements of physiological and physical traits dependent upon the specific discipline of snowboarding in question. For example, in order to meet the divers demands of each discipline, athletes must develop various qualities, such as muscular strength and power. This can increase their ability to withstand the high forces and loads on the muscular system during competition, and further decrease their risk of lower limbs injuries. At the same time, the studies acknowledge the potential advantages of aerobic fitness in terms of recovery, to more efficiently sustain the athlete through both competitive and on- and off-snow training sessions. Given the value and breadth of application of these limited studies, further analysis and research could contribute greater knowledge and benefits to the field of snowboarding. Therefore, it is the purpose of this preliminary review to explore the current literature, providing further insight into the physiological and physical demands of snowboarding performance. This preliminary review is intended to stimulate interest among the communities of exercise physiologists, sport scientists and particularly coaches in order to improve our current understanding of snowboarding and its demands as a sport. This preliminary review further seeks to develop protocols and strategies to assess physiological and performance characteristics of snowboarding, monitor athletic performance, provide practical recommendations for training, identify new areas of scientific research, and develop accurate talent identification programs

Does the Running Economy Really Increase after Ultra-Marathons?

[no abstract available

An Extreme Mountain Ultra-Marathon Decreases the Cost of Uphill Walking and Running

Purpose: To examine the effects of the world's most challenging mountain ultramarathon (MUM, 330 km, cumulative elevation gain of +24,000 m) on the energy cost and kinematics of different uphill gaits. Methods: Before (PRE) and immediately after (POST) the competition, 19 male athletes performed three submaximal 5-min treadmill exercise trials in a randomized order: walking at 5 km.h-1, +20%; running at 6 km.h-1, +15%; and running at 8 km.h-1, +10%. During the three trials, energy cost was assessed using an indirect calorimetry system and spatiotemporal gait parameters were acquired with a floor-level high-density photoelectric cells system. Results: The average time of the study participants to complete the MUM was 129 h 43 min 48 s (range: 107 h 29 min 24 s to 144 h 21 min 0 s). Energy costs in walking (-11.5 +/- 5.5%, P < 0.001), as well as in the first (-7.2 +/- 3.1%, P = 0.01) and second (-7.0 +/- 3.9%, P = 0.02) running condition decreased between PRE and POST, with a reduction both in the heart rate (-11.3, -10.0, and -9.3%, respectively) and oxygen uptake only for the walking condition (-6.5%). No consistent and significant changes in the kinematics variables were detected (P-values from 0.10 to 0.96). Conclusion: Though fatigued after completing the MUM, the subjects were still able to maintain their uphill locomotion patterns noted at PRE. The decrease (improvement) in the energy costs was likely due to the prolonged and repetitive walking/running, reflecting a generic improvement in the mechanical efficiency of locomotion after ~130 h of uphill locomotion rather than constraints imposed by the activity on the musculoskeletal structure and function

Isokinetic strength of foot dorsal and plantar flexor muscles in young male orienteers

Map and compass allow orienteers navigating point to point in unfamiliar and uneven grounds. High levels of fitness and running speed are requested to cover successfully long distances and climbs. Lower limb muscular strength is necessary to sustain challenging descents on rough terrains (Fong et al., 2007). Eight male junior (age, 19±1.6yr) Italian national team orienteers (OR), and 8 cross country track and fields (TF) experienced runners (20±4.5yr), all with right lower limb dominance volunteered. Ages, weights, heights, and BMI of OR and TF did not differ (ANOVA, p>0.05). Each participant performed, and an isokinetic dynamometer measured 5 repetitions of right and left foot dorsal and plantar flexions at the angular speeds of 60-120-180deg/sec respectively. Each value was normalized to the body weight of the respective subject. Descriptive statistics were computed within subject, group, movement, angular speed, and side. For each movement, the effects of group and side on the peak torques at different speeds were compared by ANOVA (statistical significance 5%). On average in both groups, right foot dorsal and plantar flexor muscles were stronger than those of contralateral limb, for all the angular speeds, but no significant differences were found. OR performed peak torques larger than those obtained by TF, in both sides and movements. Differences were significant in foot plantar flexor muscles at 60-120-180deg/sec, and in foot dorsal flexor muscles at 60-120deg/sec (p≤0.04 for all comparisons). The investigation should be extended to a larger group of participants and to other muscular districts. Data could be of interest for athletes, coaches, and physicians to set a correct training planning, to prevent accidental injuries, or to quantify the effects of rehabilitation (Fong et al., 2007)

Injury and Illness Rates During Ultratrail Running

This study aimed to describe injury/illness rates in ultratrail runners competing in a 65-km race to build a foundation for injury prevention and help race organizers to plan medical provision for these events. Prospectively transcribed medical records were analysed for 77 athletes at the end of the race. Number of injuries/illnesses per 1\u2009000 runners and per 1\u2009000-h run, overall injury/illness rate and 90% confidence intervals and rates for major and minor illnesses, musculoskeletal injuries, and skin disorders were analysed. A total of 132 injuries/illnesses were encountered during the race. The overall injuries/illnesses were 1.9 per runner and 13.1 per 1\u2009000-h run. Medical illnesses were the most prominent medical diagnoses encountered (50.3%), followed by musculoskeletal injuries (32.8%), and skin-related disorders (16.9%). Despite the ultra-long nature of the race, the majority of injuries/illnesses were minor in nature. Medical staff and runners should prepare to treat all types of injuries and illnesses, especially the fatigue arising throughout the course of an ultratrail run and injuries to the lower limbs. Future studies should attempt to systematically identify injury locations and mechanisms in order to better direct injury prevention strategies and plan more accurate medical care

Isokinetic strength of foot plantar and dorsal flexors in young male orienteers

Orienteers navigate point to point in unfamiliar and uneven grounds using map and compass to run their races. High levels of fitness and running speed are requested to cover successfully long distances and climbs. Strength in ankle and foot muscles is necessary to overcome natural obstacles in rough terrains (1). Eight male orienteers of junior Italian team (OR; age, 19\ub11.6yr), 8 cross country track and fields experienced runners (TF; 20\ub14.5yr), and 8 sedentary persons (control group CG; 23\ub12.7yr), all with right lower limb dominance volunteered. Ages, weights, heights, and body mass indices between groups did not differ (ANOVA, p>0.05). Each participant performed and an isokinetic dynamometer measured 4 repetitions of right and left foot dorsal and plantar flexions at the angular speeds of 60-120-180deg/sec respectively. Within side, group and angular speed, the ratios of peak torques between plantar and dorsal flexors were also computed. Descriptive statistics were calculated within subject, group, movement, angular speed, and side. For each movement, the effects of group and side, and group 7side interactions on peak torques at different speeds were compared by ANOVA (statistical significance 5%). Within group, dorsal and plantar flexors of right foot were generally stronger than those of contralateral limb, but differences were not significant. Side-related differences were similar in all groups (p>0.05). On average, OR performed larger peak torques in both sides and movements. Differences were significant in foot plantar flexors at 60-120-180deg/sec, and in foot dorsal flexors at 60 and 120deg/sec (p 640.04). In both limbs, the ratios between plantar and dorsal flexors were larger in OR at 120-180deg/sec, and in TF at 60deg/sec (p<0.01). Orienteers build their physical training mostly on overcoming natural obstacles and running on uneven grounds. This approach could stimulate a continuous proprioceptive activity, and favor the reinforcement of ankle and foot muscles. Data could be of interest for coaches to set efficient training plans preventing accidental injuries, and for physical therapists and physicians to quantify the effects of rehabilitation. Investigations should be extended to a larger group of participants and to other muscular districts

Gokyo Khumbu/Ama Dablam Trek 2012

In the expedition Gokyo Khumbu/Ama Dablam Trek 2012, we studied the effects of two 12-day training periods performed both at sea level and at high altitude. The main results on adult women have been published in six original articles. In women, high altitude trekking induced CD69 T cell activation and promoted anti-stress effects of the immune responses and the oxidative balance (1). Low-to-moderate exercise training at s.l. improves the regenerative capacity of skeletal muscle and depicted the epigenetic signature of satellite cells. The cell differentiation was favored by increased [Ca2+]i and fusion index (2). On the contrary, the training in hypobaric-hypoxia induced oxidative stress and impaired the regenerative capacity of satellite cells (6). Although training did not significantly modify muscle phenotype , it induced beneficial adaptations of the oxygen transport-utilization systems witnessed by faster VO2 kinetics at exercise onset (3). The two training periods did not influence the postural stability (4). In young adult women, micturition physiological parameters were affected during adaptation to hypoxia; the correlation with SpO2 strongly suggests a role of hypoxia in these changes (5

An analysis of pacing profiles of world-class racewalkers

PURPOSE: The aim of this study was to describe the pacing profiles used by racewalkers competing in IAAF World Championships. METHODS: The times for each 5-km segment were obtained for 225 men competing over 20 km, 214 women competing over 20 km, and 232 men competing over 50 km, of whom 49 did not finish. Athletes were grouped based on finishing position (for medalists) or finishing time. RESULTS: Different pacing profiles were used by athletes grouped by finishing time, with 20-km medalists using negative pacing and those finishing within 5% of the winning time matching the medalists' early pace but failing to maintain it. Lower-placed 20-km athletes tended to start more quickly relative to personal-best pace and experienced significant decreases in pace later. Across all competitions, the fastest finishers started the slowest relative to previous best performance. All 50-km athletes slowed toward the finish, but lower-placed finishers tended to decrease pace earlier (with up to 60% of the race remaining). After halfway in the 50-km, 8 of the 15 athletes who had a 5-km split more than 15% slower than the previous split dropped out. CONCLUSIONS: The negative pacing profile used by 20-km medalists required the ability to start fast and maintain this pace, and similarly paced training may be beneficial in race preparation. Over 50 km, the tactic of starting slower than personal-best pace was generally less risky; nonetheless, any chosen pacing strategy should be based on individual strengths