Beijing will host the 2022 Winter Olympics, and China strengthens research on various aspects to allow their athletes to compete successfully in winter sport. Simultaneously, Government-directed initiatives aim to increase public participation in recreational winter sport. These parallel developments allow research to advance knowledge and understanding of the physiological determinants of performance and health related to winter sport. Winter sport athletes often conduct a substantial amount of training with high volumes of low-to-moderate exercise intensity and lower volumes of high-intensity work. Moreover, much of the training occur at low ambient temperatures and winter sport athletes have high risk of developing asthma or asthma-related conditions, such as exercise-induced bronchoconstriction. The high training volumes require optimal nutrition with increased energy and dietary protein requirement to stimulate muscle protein synthesis response in the post-exercise period. Whether higher protein intake is required in the cold should be investigated. Cross-country skiing is performed mostly in Northern hemisphere with a strong cultural heritage and sporting tradition. It is expected that innovative initiatives on recruitment and training during the next few years will target to enhance performance of Chinese athletes in classical endurance-based winter sport. The innovation potential coupled with resourcing and population may be substantial with the potential for China to become a significant winter sport nation. This paper discusses the physiological aspects of endurance training and performance in winter sport highlighting areas where innovation may advance in athletic performance in cold environments. In addition, to ensure sustainable development of snow sport, a quality ski patrol and rescue system is recommended for the safety of increasing mass participation.
To measure changes in strength, power, and agility over consecutive seasons based on competition level in figure skaters.
A total of 197 competitive singles figure skaters (age range = 9–25 years old) completed combines with United States Figure Skating on two consecutive seasons between 2011 and 2018. Skaters either remained in the same competitive on-ice level or increased by one level on consecutive seasons. All athletes completed the hexagon agility test, maximal vertical jump, timed tuck jumps, push-ups, and bent knee v-ups. Repeated-measures analyses of variance separated by sex with Tukey’s post hoc were performed for each dependent variable and Cohen’s d effect sizes were calculated for all significant differences.
Female skaters who remained in the same level demonstrated improved performance on vertical jump (3.66 cm higher), timed tuck jumps (3.77 more jumps), v-ups (1.59 more v-ups), and hexagon jump (1.17 s faster). There was an interaction for female skaters who remained in the same level (P = 0.004), with senior and junior levels outperforming intermediate level skaters on the hexagon jump test. Female skaters who increased level demonstrated improved performance on the vertical jump (2.24 cm higher), hexagon jump (1.16 cm faster), and tuck jump (3.03 more jumps). Male skaters did not demonstrate any changes in performance except v-ups (2.86 more v-ups) for those who increased level.
The greatest changes were in lower level female skaters who remained in the same level, supporting the importance of participating in strength and conditioning programs earlier in skating careers to maximize athleticism before reaching the senior level, when changes in off-ice performance plateau.
To explore the influence of the oval (plateau or plain), the lane (inner or outer), and simultaneous entry (long distance or sprint) on the result and pacing strategy in speed skating men’s 1500 m.
Multi-factor analysis of variance, independent sample T test, Spearman correlation coefficient method, paired T test and other statistical methods are used to analyze the relationship and differences between the oval (plateau or plain), the lane (inner or outer), and/or simultaneous entry (long distance or sprint) and the results of the top 8 athletes of the ISU event in the 2019–2020 season.
Among the three factors of oval, lane, and simultaneous entry, only the altitude will improve the athlete’s performance of 1500 m, an increase of about 2.52% (2.65 s). Both the oval and the simultaneous entry will affect the athlete’s 1500 m pacing strategy. Athletes tend to adopt a more positive strategy when competing in plateau; the sprint athletes have a faster opening, but a slower ending.
At present, the level of speed skating in China and the world is in the highest period. Among the oval factors, the highland oval can significantly improve the athletes’ performance of 1500 m; athletes tend to adopt a more positive pacing strategy in the plateau than in the plain. In the process of preparing for the 2022 Winter Olympic Games, we can predict the competitive level of the opponent through the plateau competition results and carry out targeted preparation. Different lanes do not affect the athlete’s 1500 m performance and pacing strategy but may affect the athlete’s final lap speed. There is no obvious difference between the sprint and long-distance athletes on the performance of 1500 m, but the sprint athletes have a faster opening and a slower ending, and the long-distance athletes have a faster final lap and a smaller drop between each lap.
The purpose of this study was to examine the effect of pole length on performance and technique selection during a simulated skating cross-country (XC) skiing competition on snow in female XC skiers.
Nine female XC skiers and biathletes (VO2max 63.6 ± 6.2 mL/min/kg, age 22.9 ± 3.5 years, body height 1.69 ± 0.1 m and body mass 60.8 ± 4.6 kg) completed two 5-km skating time-trail with maximal effort. The athletes had a minimum 4.5 h of rest between the two races, which were performed in a random order: one with self-selected poles (89.0% ± 0.6% of body height) and one with 7.5 cm increased pole length (94.0% ± 0.5% of body height). Speed in set terrain sections was determined and the selection of sub-technique was self-reported immediately after each race based on a detailed review of the entire track.
Skiers performed on average 7.1 ± 7.1 s (P = 0.029) faster with the long poles, with this difference occurring during the first 200 m and in the uphill parts of the track, in which ~ 5% more G3 and ~ 5% fewer G2 sub-techniques were chosen (both P < 0.05). The rating of perceived exertion was 1 ± 0.9 point lower (P = 0.04) and skiing technique was perceived to be ~ 1.2 ± 1.5 points better with long poles (P = 0.038), while the physiological responses (i.e., peak and average heart rate, and blood lactate concentration) did not differ between trials.
In conclusion, poles 7.5 cm longer than self-selected ones improved performance in skating, by enhancing speed in the initial phase (first 200 m) and in the uphill section of the track. In addition, the longer poles induced more use of the G3 skating sub-technique.
To investigate the physiological responses to low-load, superset resistance training (two exercises for the agonist and antagonist muscles performed without rest between exercises) to failure using elastic bands.
Twenty-three athletes were randomized to either a superset group (S, n = 12, average age: 19.8 ± 1.5 years) or a traditional set group (T, n = 11, average age: 20.1 ± 1.4 years). Strength, cross-sectional area (CSA) and muscular endurance of the biceps and triceps brachii were assessed before and after 8 weeks. Acute responses (muscle thickness) were measured during one testing session.
Muscle thickness of the biceps significantly increased in both T group (P < 0.05) and S group (P < 0.05) after a single bout of Training. The triceps did not show significant increases in either T group (P > 0.05) or S group (P > 0.05). Blood lactate also increased in both groups after one bout of training (T: from 1.3 ± 0.3 to 5.5 ± 2.4 mmol/L, S: from 1.4 ± 0.5 to 5.1 ± 1.5 mmol/L, P < 0.05). After 8-week training, both groups showed significant increases in the biceps (T: 13.2% ± 5.0%; S: 12.9% ± 7.3%, P < 0.05) and triceps (T: 9.5% ± 9.3%, S: 4.8% ± 4.1%, P < 0.05) without differences between groups. Increases in one repetition maximum for the bench press (7.8% ± 6.5%, P < 0.05) and maximal voluntary contraction for the arm extensors (9.3% ± 11.6%, P < 0.05) were observed for the T group only. Increases in muscular endurance were observed only in the S group for the bench press (26.0% ± 19.1%, P < 0.05) and the barbell curl (17.2% ± 16.6%, P < 0.05).
Superset training may enhance muscular endurance while attenuating maximal strength gains. There does not appear to be a hypertrophic benefit to performing superset training, but it may provide a time-efficient strategy to achieve adaptations in muscle mass.
The purpose of this study was to examine the influence of muscle length and fatigue on maximal force, submaximal force steadiness, and electromyographic (EMG) activity of the biceps brachii.
Force and EMG responses were measured before and after a fatigue protocol consisting of maximal intermittent contractions of the elbow flexors until task failure (n = 20). The protocol was performed on two separate occasions in a randomized order. During one visit, the elbow joint was at 90° (EF90) and for the other, it was extended to 120° (EF120).
The results show a large effect size for greater force loss following fatigue at long muscle length (P = 0.067, $\eta_{p}^{2}$ = 0.166). The fatigue-based decreases in force steadiness were not different between muscle lengths (P = 0.502, $\eta_{p}^{2}$ = 0.024). Force steadiness was lower at long muscle length before and after fatigue (P < 0.01, d = 0.691). Following fatigue, muscle excitation decreased and increased during maximal and submaximal force tasks, respectively, yet there were no length-dependent EMG responses.
The novel findings show fatigue at long muscle length likely affects force loss to a greater degree than fatigue-based decreases in force steadiness. These data show lower elbow flexion force steadiness when the biceps brachii is in a lengthened position.
The purpose of this study was to explore the relationship between two measures of trunk muscular endurance.
Retrospective data for 520 male law enforcement officers (age 40.16 ± 7.71 years; height = 1.81 ± 0.07 m; body mass = 94.4 ± 15.01 kg) belonging to a single US based law enforcement agency were used for this analysis. The data provided included: age, height, body mass, sit-up repetitions completed in 1-min (SU) and time to completion for the isometric prone plank (IPP). A Pearson’s product correlation coefficient was used to determine the relationships between the SU and IPP.
Significant (P < 0.001) moderate (r = 0.594, R 2 = 0.352) relationships were discovered between the SU and IPP.
Based on the results of this study it appears that both the SU and IPP tests are appropriate for evaluating trunk muscular endurance, but measure separate qualities (i.e., dynamic and static muscular endurance).
In kettlebell sport (KS) half marathon, the lift of the kettlebell is required for the highest number of repetitions in 30 min. No data are available on cardiorespiratory and metabolic responses during this exercise routine. The aim of the study was to evaluate cardiopulmonary and metabolic responses to KS half marathon compared to 30 min treadmill running, chosen as a reference paradigm of aerobic exercise, at the same average oxygen consumption (VO2).
A male elite KS athlete was enrolled in two trials separated by 7 days of rest. In the first trial, one-hand long-cycle KS exercise with a 1/3 body weight kettlebell was performed for 30 min (kettlebell half marathon, KT); in the second trial, 30 min treadmill running (TR) was performed at the same average VO2 measured in the first trial (speed 9–10 km/h at 1° uphill inclination). Metabolic and cardiopulmonary assessments [respiratory exchange ratio (RER), tidal volume (TV), breathing frequency (f), minute ventilation (VE)], blood lactate (BL) kinetics, heart rate (HR), and blood pressure (BP) were measured in both experimental sessions.
The average VO2 was 33.3 mL/min/kg in KT and 30.6 mL/min/kg in TR. The subject achieved RERpeak 1.17, RERmean 0.98, HRpeak 172 bpm (94% HRmax), HRmean 86% of HRmax, BPpeak 220/100 mmHg in KT, BLpeak 7.2 mmol/L (during trial) in KT and RERpeak 1.13, RERmean 0.89, HRpeak 142 bpm (78% HRmax), HRmean 70% of HRmax, BPpeak 160/80 mmHg, BLpeak 3.5 mmol/L (4 min after trial) mmol/L in TR.
Data indicate that a KS half marathon determines much higher cardiopulmonary and metabolic responses to treadmill running performed at similar VO2.
The primary aim of this study is to determine the prevalence of vitamin D deficiency and insufficiency among Asian athletes participating in indoor and outdoor sports in equatorial Singapore. Secondary aims are to examine the relationship between vitamin D status and skeletal muscle strength and performance, and bone density.
Serum 25(OH)D concentrations were determined in 95 indoor and outdoor athletes across various sports. Skeletal muscle strength and performance were assessed using the isometric mid-thigh pull (IMTP), drop jump test and 30 m sprint test. Bone Mineral Density (BMD) was measured using Dual-energy X-ray Absorptiometry (DXA).
Mean serum 25(OH)D concentrations were 28.6 ± 8.9 ng/mL among indoor, and 39.2 ± 13.2 ng/mL among outdoor sport athletes respectively (P < 0.05). More indoor sport athletes (62%) had insufficient vitamin D compared to outdoor sport athletes (30%) (P < 0.05). Outdoor sport athletes exhibited significantly greater peak force generation than indoor sport athletes (2079 ± 470 N vs. 1869 ± 546 N, P = 0.027). Other markers of muscle function were not significantly different between groups. Indoor and outdoor sport athletes did not have significantly different BMDs although none of the athletes studied presented with poor BMD. Athletes who were deficient in vitamin D had significantly lower BMD compared to athletes with sufficient vitamin D (P = 0.01).
Forty-seven percent of Singaporean athletes studied had suboptimal vitamin D status. Routine monitoring of vitamin D levels among indoor sport athletes should be in place to ensure optimal health and performance.
The current study aimed to assess the changes in physical and perceptual markers of health, fitness, and well-being over the first semester of university study in a New Zealand context.
In a pre-post longitudinal design, 90 first-year university students (39 females, 51 males, mean ± SD age: 18 ± 2 years) studying in the field of health, sport and human performance underwent tests of body mass, height, body mass index (BMI), blood pressure, predicted VO2max, flexibility, countermovement jump height, handgrip strength, isometric mid-thigh pull strength, and well-being pre and post the first semester of university study (12 weeks).
When evaluating the entire group, there was a significant increase in body mass (0.66 kg, P = 0.004) and BMI (0.2 kg/m2, P = 0.005) and decrease in the “engagement” construct of the well-being questionnaire (− 0.2, P = 0.03) over the first semester of university. In total, 73% of students living on-campus reported a decline in sleep and nutrition habits since starting university, in comparison to ~ 35%–40% of students living off-campus (P ≤ 0.03).
Similar to results seen in other countries, and despite the field of study, the first semester of university in New Zealand is likely to be associated with increases in body mass and BMI; however, changes in physical fitness and overall well-being measures were less obvious in the current study.
Powerlifting regularly exposes athletes to extreme stimuli such as chronic heavy resistance training (HRT), and many powerlifters choose to augment their performance with anabolic–androgenic steroids (AAS). However, little is known about the myocellular adaptations that occur from long-term HRT and AAS use, especially into middle age. We were presented with the unique opportunity to study muscle cells from an elite-level powerlifter (EPL; age 40 years) with ≥ 30 years of HRT experience and ≥ 15 years of AAS use. The purpose of this case study was to identify myocellular characteristics [myosin heavy chain (MHC) fiber type, fiber size, and myonuclear content] in EPL, as well as compare these data to existing literature. The participant underwent a resting vastus lateralis muscle biopsy and single fibers were analyzed for MHC content via SDS-PAGE. A subset of fibers underwent MHC-specific imaging analysis via confocal microscopy to identify cell size (cross-sectional area, CSA) and myonuclear domain (MND) size. MHC fiber type distribution was 9% I, 12% I/IIa, 79% IIa, and 0% other isoforms. This pure MHC IIa (fast-twitch) fiber content was amongst the highest reported in the literature. Imaging analysis of MHC IIa fibers revealed a mean CSA of 4218 ± 933 μm2 and MND of 12,548 ± 3181 μm3. While the fast-twitch fiber CSA was comparable to values in previous literature, mean MND was smaller than has been reported in untrained men, implying greater capacity for growth and repair. These findings showcase the unique muscle cell structure of an elite powerlifter, extending the known physiological limits of human muscle size and strength.