The Modifications of Haemoglobin, Erythropoietin Values and Running Performance While Training at Mountain vs. Hilltop vs. Seaside

Altitude training increases haemoglobin, erythropoietin values among athletes, but may have negative physiological consequences. An alternative, although less explored, that has the potential to positively influence performance while avoiding some of the negative physiological consequences of hypoxia is sand training. Ten endurance-trained athletes (age: 20.8 ± 1.4, body mass: 57.7 ± 8.2 kg, stature: 176 ± 6 cm; 5000 m 14:55.00 ± 0:30 min) performed three 21-day training camps at different locations: at a high altitude (HIGH), at the sea-level (CTRL), at the sea-level on the sand (SAND). Differences in erythropoietin (EPO) and haemoglobin (Hb) concentration, body weight, VO2max and maximal aerobic velocity (VMA) before and after each training cycle were compared. Data analysis has indicated that training during HIGH elicited a greater increase in VO2max (2.4 ± 0.2%; p = 0.005 and 1.0 ± 0.2%; p < 0.001) and VMA (2.4 ± 0.2%, p < 0.001 and 1.2 ± 0.2%; p = 0.001) compared with CTRL and SAND. While increases in VO2max and VMA following SAND were greater (1.3 ± 0.1%; p < 0.001 and 1.2 ± 0.1%; p < 0.001) than those observed after CTRL. Moreover, EPO increased to a greater extent following HIGH (25.3 ± 2.7%) compared with SAND (11.7 ± 1.6%, p = 0.008) and CTRL (0.1 ± 0.3%, p < 0.001) with a greater increase (p < 0.01) following SAND compared with CTRL. Furthermore, HIGH and SAND elicited a greater increase (4.9 ± 0.9%; p = 0.001 and 3.3 ± 1.1%; p = 0.035) in Hb compared with CTRL. There was no difference in Hb changes observed between HIGH and SAND (p = 1.0). Finally, athletes lost 2.1 ± 0.4% (p = 0.001) more weight following HIGH vs. CTRL, while there were no differences in weight changes between HIGH vs. SAND (p = 0.742) and SAND vs. CTRL (p = 0.719). High-altitude training and sea-level training on sand resulted in significant improvements in EPO, Hb, VMA, and VO2max that exceeded changes in such parameters following traditional sea-level training. While high-altitude training elicited greater relative increases in EPO, VMA, and VO2max, sand training resulted in comparable increases in Hb and may prevent hypoxia-induced weight loss.

Training status affects between-protocols differences in the assessment of maximal aerobic velocity

Purpose Continuous incremental protocols (CP) may misestimate the maximum aerobic velocity (Vmax) due to increases in running speed faster than cardiorespiratory/metabolic adjustments. A higher aerobic capacity may mitigate this issue due to faster pulmonary oxygen uptake ($$\dot{V}$$ V ˙ O2) kinetics. Therefore, this study aimed to compare three different protocols to assess Vmax in athletes with higher or lower training status. Methods Sixteen well-trained runners were classified according to higher (HI) or lower (LO) $$\dot{V}$$ V ˙ O2max$$\dot{V}$$ V ˙ O2-kinetics was calculated across four 5-min running bouts at 10 km·h−1. Two CPs [1 km·h−1 per min (CP1) and 1 km·h−1 every 2-min (CP2)] were performed to determine Vmax$$\dot{V}$$ V ˙ O2max, lactate-threshold and submaximal $$\dot{V}$$ V ˙ O2/velocity relationship. Results were compared to the discontinuous incremental protocol (DP). Results Vmax, $$\dot{V}$$ V ˙ O2max, $$\dot{V}$$ V ˙ CO2 and VE were higher [(P < 0.05,(ES:0.22/2.59)] in HI than in LO. $$\dot{V}$$ V ˙ O2-kinetics was faster [P < 0.05,(ES:-2.74/ − 1.76)] in HI than in LO. $$\dot{V}$$ V ˙ O2/velocity slope was lower in HI than in LO [(P < 0.05,(ES:-1.63/ − 0.18)]. Vmax and $$\dot{V}$$ V ˙ O2/velocity slope were CP1 > CP2 = DP for HI and CP1 > CP2 > DP for LO. A lower [P < 0.05,(ES:0.53/0.75)] Vmax-difference for both CP1 and CP2 vs DP was found in HI than in LO. Vmax-differences in CP1 vs DP showed a large inverse correlation with Vmax, $$\dot{V}$$ V ˙ O2max and lactate-threshold and a very large correlation with $$\dot{V}$$ V ˙ O2-kinetics. Conclusions Higher aerobic training status witnessed by faster $$\dot{V}$$ V ˙ O2 kinetics led to lower between-protocol Vmax differences, particularly between CP2 vs DP. Faster kinetics may minimize the mismatch issues between metabolic and mechanical power that may occur in CP. This should be considered for exercise prescription at different percentages of Vmax.

Physiological and Race Pace Characteristics of Medium and Low-Level Athens Marathon Runners

This study examined physiological and race pace characteristics of medium- (finish time < 240 min) and low-level (finish time > 240 min) recreational runners who participated in a challenging marathon route with rolling hills, the Athens Authentic Marathon. Fifteen athletes (age: 42 ± 7 years) performed an incremental test, three to nine days before the 2018 Athens Marathon, to determine maximal oxygen uptake (VO2 max), maximal aerobic velocity (MAV), energy cost of running (ECr) and lactate threshold velocity (vLTh), and were analyzed for their pacing during the race. Moderate- (n = 8) compared with low-level (n = 7) runners had higher (p < 0.05) VO2 max (55.6 ± 3.6 vs. 48.9 ± 4.8 mL·kg−1·min−1), MAV (16.5 ± 0.7 vs. 14.4 ± 1.2 km·h−1) and vLTh (11.6 ± 0.8 vs. 9.2 ± 0.7 km·h−1) and lower ECr at 10 km/h (1.137 ± 0.096 vs. 1.232 ± 0.068 kcal·kg−1·km−1). Medium-level runners ran the marathon at a higher percentage of vLTh (105.1 ± 4.7 vs. 93.8 ± 6.2%) and VO2 max (79.7 ± 7.7 vs. 68.8 ± 5.7%). Low-level runners ran at a lower percentage (p < 0.05) of their vLTh in the 21.1–30 km (total ascent/decent: 122 m/5 m) and the 30–42.195 km (total ascent/decent: 32 m/155 m) splits. Moderate-level runners are less affected in their pacing than low-level runners during a marathon route with rolling hills. This could be due to superior physiological characteristics such as VO2 max, ECr, vLTh and fractional utilization of VO2 max. A marathon race pace strategy should be selected individually according to each athlete’s level.

Physiological and Race Pace Characteristics of Medium and Low-Level Athens Marathon Runners

Aim: Maximum oxygen uptake (VO2max), running economy, and lactate threshold (LT) velocity are interacting factors which determine the running speed that that can be sustained in an endurance event such as Athens marathon. The aim of this study was to examine the physiological characteristics and the race pace characteristics in relation to the aforementioned parameters of moderate (finish time < 240 min) and low-level runners (finish time > 240 min) of the Athens marathon race. Material & Method: 15 athletes (age, 41 ± 7 yrs; height, 174.5 ± 6.6 cm; and body mass, 72.8 ± 6.9 kg), who participated in the 2018 Athens marathon, performed an incremental test until exhaustion, 3 to 10 days before the race to determine VO2max, maximal aerobic velocity (MAV), and the velocity at the 1st LT. The athletes were divided into a moderate level (n = 8, finish time, 209.0 ± 10.4 min) and a low-level group (n = 7; finish time, 289.7 ± 25.1 min). Finish time was exported from the results posted on the official site of the organization. Results: For the whole sample, VO2max was 52.4 ± 5.2 mL/kg/min, MAV 15.5 ± 1.4 km/h, and velocity at the 1st LT 10.6 ± 1.4 km/h, corresponding to 68.0 ± 5.4% of MAV and to 75.0 ± 8.8% of VO2max. The mean finish time was 246.7 ± 45.4 min, and the average running velocity 10.6 ± 1.9 km/h, which corresponded to 99.9 ± 7.5% of the velocity at the 1st LT and 75.0 ± 8.8% of VO2max. Moderate level, compared with the low-level athletes had higher (p < 0.05) VO2max (55.5 ± 3.5 vs. 48.8 ± 4.8 mL/kg/min), MAV (16.5 ± 0.7 vs. 14.4 ± 1.2 km/h), and velocity at 1st LT (11.6 ± 0.8 vs. 9.4 ± 1.0 km/h, corresponding to 70.5 ± 4.0 vs. 65.2 ± 5.6% of MAV). Medium-level athletes ran the marathon at a higher velocity (12.1 ± 0.6 vs. 8.8 ± 0.9 km/h), corresponding to a higher percentage of MAV (73.8 ± 2.6 vs. 61.3 ± 42%), 1st LT (104.8 ± 4.8 vs. 94.2 ± 5.8%), and VO2max (80.0 ± 7.8 vs. 69.3 ± 6.5%). Conclusions: These findings suggest that athletes of different levels run the Athens marathon at a rate corresponding to different percentages of key parameters of aerobic performance. It is recommended that the selected pace be applied individually according to each athlete’s level.

Avaliação da velocidade crítica de corrida em pista e esteira: perfis fisiológicos e relações com o desempenho em 3000 metros

The present study aiming to verify the interference of different conditions (treadmill vs. track) on critical velocity (CV) values, as well as on the correlation to the 3000-meter performance (v3000m), and thus infer about the specificity of each values as training parameter for this distance. Seven runners (15.3±1.4 years) were submitted to a maximal progressive test (1.0 km×h-1 increments per minute until exhaustion) to assess V̇O2max and maximal aerobic velocity (vV̇O2max). Subsequently, CV was estimated from three running performances at each test condition, with exercise intensities adjusted for different time limits (tLim) at 900, 2100 and 3300 meters in track or at 90, 95 and 115% of vV̇O2max in treadmill. From linear adjustments, using stepwise method, CV was assessed on treadmill (CVTREADMILL) and track (CVTRACK), and both compared by the Mann-Whitney test. The sample-adjusted dispersion coefficient (R2 adj) analyzed the varianceof v3000m with CVTRACK, CVTREADMILL and vV̇O2max. In all analyses, significance was set at P≤0.05. In progressive test, V̇O2max reached 54.2±5.2 mLO2×kg-1×min-1 and vV̇O2max reached 16.8±1.9 km×h-1. No differences were observed between CVTREADMILL and CVTRACK (14.0±1.8 vs. 12.3±3.2 km×h-1, P=0.46). Correlations were observed for v3000m with CVTREADMILL (R2 adj ~0.94), CVTRACK (R2 adj ~0.99) and vV̇O2max (R2 adj ~0.90), all showing P=0.001. It could be concluded that no influence was observe on the ability to achieve identical CV values from different assessment conditions. The correlation to the v3000 meters suggested better specificity of CVTRACK than CVTREADMILL for training prescription and performance control.

Acute caffeine supplementation retards aerobic and lactic anaerobic performance decline following a simulated futsal protocol

The aim of this study was to examine the effect of caffeine supplementation on aerobic, lactic anaerobic and alactic anaerobic performances in male futsal plyers following a simulated futsal match.Methods: Twenty trained futsal players (age= 34.05±3.7 yr., weight=74.38±8.65 kg, height= 1.75± 4.3 cm, body fat%=20.82±5.6 and BMI=24.15±2.62 kg/m2) participated in this single group, placebo controlled and single blinded study. The participants conducted tow simulated futsal games with 1 week break between them after ingesting either caffeine (3mg/kg body mass) or placebo. The subjects consumed the same food 24 hr. before each protocol protocol. At the baseline and immediately after tow protocols, alactic anaerobic, lactic anaerobic, and aerobic performances were assessed using Sargent jump test, Running based anaerobic sprint (RAST) test and 5 minutes running field test as a measurement of maximal aerobic velocity, respectively. The data were analyzed using repeated measures of analysis of variance.Results: After futsal simulation under caffeine or placebo condition, There were no significant (p≥0.05) differences on alactic anaerobic performance compared to baseline, and alactic anaerobic power output was not significantly(p≥0.05) different between tow conditions after simulated protocol. After futsal simulation, aerobic and lactic anaerobic performances for caffeine and placebo conditions were significantly (p≤0.05) lower that the baseline. Post protocol aerobic and lactic anaerobic performance measures were found significantly (p≤0.05) higher in the caffeine condition than that of in the placebo.Conclusions: Based on these results it can be said that 3 mg/kg body mass acute caffeine supplementation retards aerobic and lactic anaerobic performances decline after simulated futsal protocol. But it is not clear whether these ergogenic effects influence performance during futsal game. Therefore the results need to be confirmed during simulated and true futsal games.

Cardiorespiratory Responses to Continuous and Intermittent Exercises in Children

The aim of the study was to characterize aerobic responses to high intensity intermittent (HIIE) and continuous (CE) exercises in prepubertal children. 26 children aged 8 to 11-year-old took part in a preliminary session to determine peakVO2 and Maximal Aerobic Velocity (MAV). In 5 subsequent experimental visits, the participants completed 2 CE and 3 HIIE sessions in a randomized order. HIIE consisted of short intermittent 10-s and 20-s running bouts at 100 to 130% MAV, interspersed with recovery periods of equal duration (S-HIIE1 and S-HIIE2 respectively) and 5-s of sprinting and jumping at maximal intensity with 15-s recovery periods (S-HIIE3). CE consisted of 2 10-min running periods at 80% and 85% MAV with a 5-min recovery period. CE protocols elicited higher average VO2 and exercise time spent above 95% of peakVO2 compared to the HIIE protocols. S-HIIE 1 and S-HIIE 2 elicited similar average VO2 response, higher than S-HIIE 3. Our study shows that CE activated the aerobic system to a greater extent than S-HIIE in prepubertal children, as reflected by the time above 95% of peakVO2 during exercise. However, isotime S-HIIE protocols comprising 10-s or 20-s exercise bouts at an intensity above MAV result in similar times above 95% of peakVO2 during exercise.

Biomechanical Changes During a 50-minute Run in Different Footwear and on Various Slopes

The effects of footwear and inclination on running biomechanics over short intervals are well documented. Although recognized that exercise duration can impact running biomechanics, it remains unclear how biomechanics change over time when running in minimalist shoes and on slopes. Our aims were to describe these biomechanical changes during a 50-minute run and compare them to those observed in standard shoes. Thirteen trained recreational male runners ran 50 minutes at 65% of their maximal aerobic velocity on a treadmill, once in minimalist shoes and once in standard shoes, 1 week apart in a random order. The 50-minute trial was divided into 5-minute segments of running at 0%, +5%, and –5% of treadmill incline sequentially. Data were collected using photocells, high-speed video cameras, and plantar-pressure insoles. At 0% incline, runners exhibited reduced leg stiffness and plantar flexion angles at foot strike and lower plantar pressure at the forefoot and toes in minimalist shoes from minute 34 of the protocol onward. However, only reduced plantar pressure at the toes was observed in standard shoes. Overall, similar biomechanical changes with increased exercise time were observed on the uphill and downhill inclines. The results might be due to the unfamiliarity of subjects to running in minimalist shoes.

Effects of Various Cognitive Video Stimulations on the Measured Stamina of Runners

This study assessed whether cognitive stimulations could improve running performance. Nine trained men (22.6 ± 2.1 years old) performed four tests of stamina i) a control test (CT) at 100% of maximal aerobic velocity without any specific attention instructions, ii) a video self modeling test filmed from behind (VB), where runners attended to a video-loop of themselves, iii) a video self modeling test filmed from the front (VF), and iv) a video of landscapes (VL) with music. The results revealed a significant increase (p = .004) of stamina in all video conditions: VB (235 ± 59 s); VF (229 ± 53 s); VL (242 ± 57 s), compared with CT (182 ± 33 s). The results showed that the oxygen consumption was significantly lower (p = .02) in VB. Two distinct processes could explain these results including the active role of mirror neurons and the influence of music.