Military and law enforcement members’ shooting ability is influenced by their postural balance, which affects their performance and survivability. This study aimed to investigate the effects of a proprioception training program (standing or walking on unstable surfaces) on postural balance and shooting performance. Twenty participants, divided into two groups, completed 60 shots in a shooting simulator while standing, before and after a 4-week proprioception training program. One group (n = 10) followed the training program (EXP), while the other group followed the regular military academy program (CON). The shooting was conducted under four conditions: without load on a stable surface, with load on a stable surface, without load on an unstable surface, and with load on an unstable surface. The findings reveal that the training program had a significant impact on the EXP, improving their balance (p < 0.01). Additionally, only in the EXP, shooting score and the percentage center of gravity increased (p < 0.01) and the stability of the shots, measured by holding time on the target, doubled from 2.2 to 4.5 s (p < 0.01). These improvements were more pronounced when participants had a load and/or were on an unstable surface. In conclusion, a proprioception training program could be beneficial for improving postural balance and shooting performance.

The purpose of this study was to examine the effects of active recovery (AR) and passive recovery (PR) using short (2-min) and long (4-min) intervals on swimming performance. Twelve male competitive swimmers completed a progressively increasing speed test of 7 × 200-m swimming repetitions to locate the speed before the onset of curvilinear increase in blood lactate concentration (LT₁). Subsequently, performance time of 6 × 50-m sprints was recorded during four different conditions: (i) 2-min PR (PR-2), (ii) 4-min PR (PR-4), (iii) 2-min AR (AR-2) and (iv) 4-min AR (AR-4) intervals. Blood lactate concentration was measured before the first and after the last 50-m repetition. AR was applied at an intensity corresponding to LT₁. Performance as indicated by the time needed to complete 6 × 50-m sprints was impaired after AR-4 compared to PR-4 (AR-4: 28.65 ± 1.04, PR-4: 28.17 ± 0.72 s; mean% difference: MD% ±s; ±90% confidence limits: 90%CL, 1.71 ± 3.01%; ±1.43%, p = .01) but was not different between AR-2 compared to PR-2 conditions (AR-2: 28.68 ± 0.85, PR-2: 28.69 ± 0.82 s; MD%: 0.03 ± 1.61%; 90%CL ± 0.77%, p = .99). Performance in sprint-6 was improved after AR compared to PR independent of interval duration (AR: 28.55 ± 0.81, PR: 29.01 ± 1.03 s; MD%: 1.52 ± 2.61%; 90%CL ± 1.2%; p = .03). Blood lactate concentration was lower after AR-4 compared to PR-4 but did not differ between AR-2 and PR-2 conditions. In conclusion, AR impaired performance after a 4-min but not after a 2-min interval. A better performance during sprint-6 after AR could be attributed to a faster metabolic recovery or anticipatory regulatory mechanisms towards the end of the series especially when adequate 4-min active recovery interval is applied.

Background: The repeated sprint ability (RSA) has been studied with protocols using distances longer than 20 m per sprint, whereas basketball players cover on average less than 20-meter distance per sprint during match. Objectives: The aim of the present study was to examine the physiological impact of 10 × 15 m RSA test in straight-line (RSASL) or with change of direction (RSACOD), i.e. 10 × (7.5 + 7.5 m)) in young national level basketball players. Patients and Methods: Young basketball players (n = 11, age 17.1 (1.0) years, body mass 76 (6) kg, height 184 (4) cm, body mass index 22.6 (1.8) kgm^-2, sport experience 6.9 (2.7) years, mean (standard deviation)) and a control group consisting of high-school athletes (n = 7, 16.1 (0.7) years, 67 (6) kg, 177 (6) cm, 21.5 (1.0) kgm^-2, 7.7 (1.6) years, respectively) performed RSASL and RSACOD on a counter-balanced order. Sprints started every 30 seconds (active recovery) and there was 30 minutes break between RSA protocols; time variables were total time (TT), best time (BT) and fatigue index (FI). Countermovement jump (CMJ) was tested before and after each RSA protocol. Heart rate (HR) was continuously monitored during testing procedures. Results: Compared with RSASL, TT and BT were worst in RSACOD (38.13 vs. 27.52 s and 3.67 vs. 2.66 s, P < 0.001, respectively), whereas FI did not differ (3.8 vs. 3.5%, P = 0.388). A 2 × 2 repeated measures ANOVA showed main effect of RSA on CMJ (pre-test vs. post-test, increase + 1.8 cm, P = 0.020, η² = 0.28); there was neither main effect of RSA protocols (RSASL vs. RSACOD +0.7 cm, P = 0.251, η² = 0.08) nor an interaction between pre-post measurements and RSA protocols (P = 0.578, η² = 0.02). Compared with RSASL, RSACOD induced higher mean and peak HR responses (175 vs 172 bpm, P < 0.001, and 185 vs 182 bpm, P = 0.002, respectively). No statistical difference was observed between basketball players and control group neither for TT (27.98 vs. 26.80 seconds, + 4.4%, P = 0.149) and BT (2.71 vs. 2.59 seconds, + 4.5%, P = 0.157) in RSASL nor for TT (38.55 vs. 37.47 seconds, + 2.9%, P = 0.169) and BT (3.70 vs. 3.63 seconds, 1.8%, P = 0.414) in RSACOD. Conclusions: In conclusion, RSASL and RSACOD differed for time variables (TT and BT) and HR responses. Despite being non-significant, the trend that adding COD reduced the percentage differences in TT and BT between the two groups highlighted the role of sport specialization. Keywords: Exercise Test; Running; Performance; Team Sport; Vertical Jump

Kounalakis SN, Kostoulas I, Havenetidis K, Giossos I, Paxinos T. Cadets’ swimming and running performance with and without a combat uniform. Aviat Space Environ Med 2013; 84:39–45. Introduction: The aim was to examine whether a combat uniform (CU) influences the cadet’s exercise performance in and out of the water. Methods: Fourteen male Army Officer cadets performed on 6 separate days: 1) a maximal 400-m freestyle swimming trial; 2) a 4 × 50-m all-out freestyle swimming trial with 10 s rest in between; 3) a 50-m swim obstacle course with a CU (CU_S); 4) a 50-m swim obstacle course without a CU (NU_S); 5) a 1000-m track run with a CU (CU_R); and 6) a 1000-m track run without a CU (NU_R). In each trial, performance time, oxygen uptake ( o₂), lactate concentration ([La]), and capillary oxygen saturation (S_po₂) were recorded. Results: The mean performance time was 44.3 ± 3.1 s and 33.4 ± 1.8 s in CU_S and NU_S trials, respectively. Peak o₂ was similar in CU_S, NU_S, and 400 m (CU_S: 59.1 ± 1.1 ml · kg⁻¹ · min⁻¹, NU_S: 57.3 ± 2.1 ml · kg⁻¹ · min⁻¹, 400 m: 58.2 ± 1.6 ml · kg⁻¹ · min⁻¹). [La] was higher in CU_S than in NU_S (CU_S: 10.0 ± 2.0 mmol · L⁻¹, NU_S: 8.5 ± 1.8 mmol · L⁻¹), but it was lower in CU_S and NU_S than during the 400 m and 4 × 50 m. S_po₂ was lower (~4.5%) in CU_S than NU_S. No differences were observed between running trials. Conclusions: The results suggest that the use of CU during swimming tasks induces high demands for energy and, thus, leads to a significant impairment of the swimming performance of the cadets. However, the influence of the CU seems to be less crucial during dry land running performance.

The purpose of the study was to compare physiological and performance responses during surface and underwater fin swimming. Thirteen male, elite fin swimmers performed four repetitions of 50-m sprints using a monofin (4 x 50 m) either on surface (S) or underwater with apnea (U). Performance time and the number of lower body kicks were recorded during 4 x 50-m sprints. Lactate was evaluated before the start, after the second and the fourth sprint and five minutes into recovery. The heart rate was measured continuously and respiratory function was recorded before and after each condition. Performance time was shorter and kicking frequency was higher in U compared to S (17.73 ± 1.18 vs. 19.94 ± 1.41 s, 135 ± 18 vs. 121 ± 15 kicks∙min−1, p < 0.05). Lactate concentration was no different between conditions. Forced expiratory volume in 1 s and peak expiratory flow were no different before and after the sprints and between conditions (p > 0.05). Forced vital capacity and maximal voluntary ventilation were increased after sprints under both conditions (p < 0.05). The heart rate was decreased in U compared to S during both sprints (167–177 vs. 183–185 b∙min−1) and the recovery period (141–151 vs. 166–174 b∙min−1). Underwater and surface repeated sprint swimming present maximal dynamic and physiological responses that should be considered during fin swimming training.

Objective: This study aimed to experimentally investigate the biomechanical and performance differences between the grab start (GS) and the kick start (KS) with each leg on the kickplate (KSR, KSL) in Bi-Finswimming (BFS). It focused on the effect of foot placement on the starting block, equipped with an adjustable, inclined rear kickplate (Omega, OSB11), to determine potential performance advantages and contribute evidence-based recommendations for optimizing start techniques in competitive BFS. Methods: Thirteen national-level finswimmers (seven males, six females; age: 17.7 ± 2.1 years) voluntarily participated. Each athlete performed two trials of three start techniques (GS, KSR, KSL) over three days in a randomized order. Four synchronized cameras recorded video data. Performance metrics (time to 5 m (T5), 15 m (T15), 25 m (T25), reaction time, block time (BT), flight time (FT), and entry characteristics) along with joint angles (hip, knee, ankle), were analyzed using Kinovea software (v. 2024.1). A two-way repeated measures ANOVA (start type × gender) was conducted to analyze performance metrics, and a paired-sample t-test assessed differences in joint angles. Also, correlations between dependent (type of start) and independent variables (start-examined variables) were examined through bivariate Pearson’s r analysis. Results: No significant gender differences were found (p > 0.05). Significant differences emerged between the starting techniques, with KS showing faster T5, T15, and T25 (p < 0.001, η²_p = 0.6; p < 0.001, η²_p = 0.5; p < 0.05, η²_p = 0.3, respectively). BT was significantly longer in GS compared to KS (p < 0.001, η²_p = 0.8), while FT was shorter in GS (p = 0.002, η²_p = 0.4). Faster T5, T15, and T25 were associated with increased flight distance and longer FT in KSL. Conclusions: The kick start generally outperforms the grab start, especially in block time, in Bi-Finswimming. These preliminary results suggest that it could be considered for future discussion regarding potential legalization by the World Underwater Federation, pending further research.