Factors Affecting Sea-Level Performance Following Altitude Training in Elite Athletes

Live high train high(LHTH)is the original method of altitude training used by elite athletes to enhance sea-level perfor-mance.Whilst many anecdotal reports featuring world-class performances of elite athletes at sea-level following LHTH exist,well-controlled studies of elite athletes using altitude training under ecologically valid conditions with training well characterised are still lacking.The literature is equivocal when considering the ergogenic potential of LHTH,and given the majority of controlled studies do not report enhanced sea-level performance,some scepticism regarding the efficacy of LHTH persists.Despite this,LHTH remains a popular form of altitude training utilised by elite athletes,with numerous case studies of champion athletes employing LHTH solidifying the rationale for its use during preparation for competition.Discussion of factors affecting the response to LHTH are often related to compromising either the hypoxia induced acceleration of eryth-ropoiesis and production of red blood cells,or the maintenance of oxygen flux and training intensity at altitude.Regarding the former,iron status and supplementation,as well as hypoxic dose are often mentioned.Concerning the latter,reduced oxygen availability at altitude leading to athletes training at lower absolute intensities and the relative intensity of training sessions being clamped as equivalent to sea-level,thus also reducing absolute training intensity are frequently discussed.Other factors including immune function and the timing of competition following LHTH may also contribute to an observed performance.Less considered in the literature are those factors specific to elite athletes,namely the repeated use of altitude camps throughout a season,and the influence this may have on subsequent performance.The current narrative review aimed to summarise the current literature pertaining to LHTH in elite athletes,and furthermore describe several factors affecting performance following altitude training.

Longitudinal trajectories of athlete burnout among young table tennis players: A 3-wave study

Purpose:The purposes of this study were to examine the trajectories of athlete burnout across a 2-month period characterized by high physical,psychological,and social demands to explore(1)whether several subgroups of athletes representing distinct burnout trajectories emerged from the analyses and(2)whether athlete burnout symptoms(reduced accomplishment,sport devaluation,and exhaustion)developed in tandem or whether some burnout dimensions predicted downstream changes in other dimensions(causal ordering model).Methods:One hundred and fifty-nine table tennis players in intensive training centers completed a self-reported athlete burnout measure across 3 time points within a 2-month period characterized by high demands.Data were analyzed through latent class growth analysis.Results:Results of latent class growth analysis showed 3 distinct trajectories for each athlete burnout dimension,indicating not only linear or quadratic change but also stability in longitudinal athlete burnout perceptions.Results also suggested that the 3 dimensions of athlete burnout did not develop in tandem.Rather,the likelihood of belonging to particular emerging trajectories of sport devaluation and physical/emotional exhaustion was significantly influenced by the athletes’perception of reduced accomplishment assessed at Time 1.Thus,reduced accomplishment predicted downstream changes in the 2 other athlete burnout dimensions.Conclusion:As a whole,these results highlighted that the multinomial heterogeneity in longitudinal athlete burnout symptoms needs to be accounted for in future research.

Non-enzymatic antioxidant blood plasma profile in the period of high training loads of elite speed skaters in the altitude

At the altitude,hypoxia and training load are key factors in the development of oxidative stress.Altitude-induced oxidative stress is developed due to the depletion of antioxidant potential.In the current study,we examined the non-enzymatic antioxidant profile of blood plasma in 7 males and 5 females specializing in speed skating at a 21-day training camp at 1850m above sea level.Training included:cycling,roller skating,ice skating,strength training,and special training.At the start point and the endpoint,total hemoglobin mass(tHb-mass),hemoglobin concentration,and circulating blood volume were determined.Antioxidant profiles,hypoxic doses,hypoxic impulses,and training impulses were assessed at 3,6,10,14,and 18 days.Antioxidant profiles consisting of“urate”and“thiol”parts were registered with chemiluminometry.In the training dynamics,antioxidant parameters changed individually,but in total there was a decrease in the“urate”capacity by a factor of 1.6(p=0.001)and an increase in the“thiol”capacity by a factor of 1.8(p=0.013).The changes in“urate”capacity positively correlated(r_(S)=0.40)and the changes in“thiol”capacity negatively correlated(r_(S)=−0.45)with changes in tHb-mass.Both exercise and hypoxic factors affect the antioxidant parameters bidirectionally.They correlated with a decrease in thiol capacity and with an increase in urate capacity.The assessment of the non-enzymatic antioxidant profile can be a simple and useful addition to screening the reactive oxygen species homeostasis and can help choose the personalized training schedule,individualize recovery and ergogenic support.

Acute effects of static stretching on peak and end-range hamstring-to-quadriceps functional ratios

AIM: To evaluate if static stretching influences peak and end-range functional hamstring-to-quadriceps(H/Q) strength ratios in elite women athletes. METHODS: Eleven healthy female athletes in an elite competitive level participated to the study. All the participants fulfilled the static stretching or non-stretching(control) intervention protocol in a randomized design on different days. Two static unassisted stretching exercises, one in standing and one in sitting position, were used to stretch both the hamstring and quadriceps muscles during these protocols. The total time for the static stretching was 6 ± 1 min. The isokinetic peak torque measurements for the hamstring and quadriceps muscles in eccentric and concentric modes and the calculations for the functional H/Q strength ratios at angular velocities of 60°/s and 180°/s were made before(pre) and after(post) the control or stretching intervention. The strength measurements and functional strength ratio calculations were based during the entire- and end-range of knee extension.RESULTS: The pre-test scores for quadriceps and hamstring peak torque and end range values were not significantly different between the groups(P > 0.05). Subsequently, although the control group did notexhibit significant changes in quadriceps and hamstring muscle strength(P > 0.05), static stretching decreased eccentric and concentric quadriceps muscle strength at both the 60°/s and 180°/s test speeds(P < 0.01). Similarly, static stretching also decreased eccentric and concentric hamstring muscle strength at both the 60°/s and 180°/s test speeds(P < 0.01). On the other hand, when the functional H/Q strength ratios were taken into consideration, the pre-intervention values were not significant different between the groups both during the entire and end range of knee extension(P > 0.05). Furthermore, the functional H/Q strength ratios exhibited no significant alterations during the entire and end ranges of knee extension both in the static stretching or the control intervention(P > 0.05). CONCLUSION: According to our results, static stretching routine does not influence functional H/Q ratio. Athletes can confidently perform static stretching during their warm-up routines.

Is there stability in the performance of elite half-marathoners?

The purpose of this study was to investigate the performance stability of elite half-marathoners of both sexes.The study was composed of 24 elite athletes(12 female and 12 male),ranked among the Senior World TOP20 halfmarathoners,who completed a half-marathon race for at least three consecutive years.Tracking was tested using autocorrelations and Kappa Cohen.Autocorrelation revealed a significant association,but a decrease in correlation among the years in both sexes.The overall weighted kappa showed lower stability in performance for both sexes(K=0.191 and K=-0.245)than for males.These findings suggest that both female and male elite halfmarathoners showed low stability in performance during three events.Besides that,athletes with a better performance tended to present the highest performance stability.It is recommended that coaches track the developmental trajectories of the athletes to comprised the changes in performance across the years,as to provide environmental characteristics that can influence performance.