Gymnastik- och idrottshögskolan, GIH

The study aimed to identify a small set of fitness tests that could effectively predict performance in simulated firefighting tasks. Thirty-six (25 male and 11 female) firefighters participated in the study. Strength was evaluated with grip strength, barbell bench rows, and elevated trap bar deadlifts. Work capacity was assessed using a 3-minute pyramid test, executed with and without firefighting equipment. Firefighting performance was evaluated using a simulated work task course comprising stair climbing, hose pull, victim rescue, and equipment carry. We used backward linear regressions to derive models incorporating fitness test results, demographic variables, and oxygen uptake measures as predictors. Statistical significance was set to p < 0.05. The pyramid test without equipment accounted for 59% of the variance in task performance. When body mass and height were included, the model's predictive power increased to 71%. A final model, integrating the pyramid test, body mass, and absolute maximal oxygen uptake capacity (V̇o2max), explained 81% of performance variation. Our findings indicate that V̇o2max is the key factor in firefighter task performance, explaining 69% of the variance. The pyramid test, which estimates V̇o2max and predicted 59% of performance, is simple, time efficient, and can be conducted at stations to assess physical ability and work capacity. Incorporating the pyramid test into regular assessments can help firefighters focus on improving their work capacity, which is essential for achieving better performance.

In traditional ice hockey skates with fixed blade holders, a shorter blade radius allows for greater variation in the foot’s overall pitch angle as the contact point shifts from the rear to the front of the blade. Therefore, a shorter blade radius can help players better adapt their pitch angle to different skating demands as compared to a longer blade radius. However, reducing the blade radius also decreases the ice contact area, and when the contact becomes too limited, plowing resistance increases, creating a trade-off that can negatively impact speed and glide. To address this trade-off between maneuverability and glide resistance, a novel dynamic blade holder incorporating a rocker mechanism has been developed. This study presents a mathematical equilibrium model of the dynamic blade holder to evaluate its effect on skate pitch angle. The model demonstrates how the rocker allows independent adjustment of the pitch angle without altering blade curvature, effectively amplifying pitch changes as a function of contact point displacement. Analytical expressions describe this amplification and its dependence on rocker radius, providing practical tools for understanding and optimizing skate design. Future research should examine the biomechanical implications of this approach in real skating scenarios.

This study investigated the test–retest reliability of strength and power-related measures assessed with a portable IMTP set-up and with CMJ in elite ice hockey players from the Swedish Hockey League. Twenty-two male ice hockey players (age: 26.8 ± 5.1 yr; height: 184.5 ± 3.9 cm; body mass: 88.6 ± 5.7 kg) participated in this study. The participants performed three maximal IMTP and CMJ trials on two separate occasions. Absolute and relative variables from the portable IMTP (force and rate of force development) and CMJ (force, power, velocity, impulse, jump height, time to peak force, time to peak power, concentric duration and eccentric duration) were obtained using force plates. Excellent reliability (ICC > 0.90; CV < 5%) was observed for multiple CMJ parameters, such as peak force (ICC = 0.94; CV = 2.7%), concentric and eccentric impulse (ICC = 0.96; CV = 1.4% resp. ICC = 0.95; CV = 2.9%) and CMJ peak power (ICC = 0.93; CV = 2.3%). IMTP peak force also demonstrated excellent reliability (ICC = 0.95; CV = 2.4%). IMTP rate of force development variables yielded reliability ranging from poor to moderate (CV = 12.9–54.6%). CMJ and portable IMTP provide highly reliable assessments of most strength and power-related variables in elite male ice hockey players. While absolute peak impulse, velocity and force, power and concentric duration displayed the highest reliability and should be prioritized, RFD variables require cautious interpretation due to high variability.

Skridskor med dynamiska skenhållare kan ge hockeyspelare bättre balans, kraft och kontroll – utan att tappa fart. Forskning visar störst effekt vid baklängesåkning. Tekniken används redan i NHL och av svenska landslagsspelare.

Detailed skating velocity profiles of high-calibre ice hockey players are lacking, and an increasing number of ice hockey players are using dynamic skating blade holders, but the impact of these skates on performance remains unclear. This study aims to compare velocity profiles between dynamic and fixed blade holders across various skating techniques. Twenty high-calibre skaters from one of the three highest-ranked leagues in Sweden (age 19.7 ± 4.1 years, body mass 77.9 ± 7.6 kg) completed three maximal trials involving linear forward sprints, forward c-cuts, and backward c-cuts on two separate occasions using two different types of blade holders. Split times were recorded at 5 m intervals from 5–40 m and average velocity was calculated for each distance segment. Velocity increased every 5 m up to 40 m, independent of the blade holder type across all techniques. No significant differences in performance were observed for linear forward sprinting or forward c-cuts between the blade holder types. However, backward c-cuts showed a significant improvement in speed with the dynamic holders at several intervals: 0–5 m (2.42 m/s vs. 2.38 m/s, p = 0.048), 15–20 m (5.86 m/s vs. 5.76 m/s, p = 0.009), and 35–40 m (6.84 m/s vs. 6.67 m/s, p = 0.021), resulting in 1-2% faster split times. The results indicate that high-calibre skaters progressively increase their velocity up to 40 m in both forward and backward skating, without reaching maximal velocity. Additionally, dynamic blade holders may offer a performance advantage during backward skating, making them a valuable option for players who frequently utilise this technique in competitive play.

Most team sports consist of elements that require both a high level of strength and aerobic endurance. Because of these demands a combination of resistance and endurance training (concurrent training) is an integrated part of their weekly training program. Concurrent training can be defined as the implementation of resistance and endurance training in parallel within the same training program to develop both capacities simultaneously. Despite the wide range of benefits of concurrent training, there is evidence that adding endurance training to a resistance training protocol can compromise strength development. The underlying cause has recently started to be clarified, with substantial evidence suggesting that the design of the training program and inter-individual differences play a crucial role in determining the effect of concurrent training on strength performance. It has been suggested that the training status may have an independent influence on the results during concurrent training. Thus, it is important to acknowledge that the scientific literature on concurrent training for elite team sport athletes is very scarce, especially in females. The primary aim of this thesis was therefore to investigate the effect of concurrent training on elite team sport athletes with both sexes represented. This was done by performing one systematic review with meta-analysis and three experimental studies.

Study I is a review study addressing the effect of training status on strength development during concurrent training and the effect of same-session and different sessions of concurrent training. The result from this study suggests that adding endurance training to a resistance training protocol impairs lower-body maximal dynamic strength development in trained individuals but not in moderately trained or untrained. The data also show that the impairment appears to increase if concurrent training is performed within the same session. Given these findings, the focus of study II was to investigate the impact of intrasession exercise order during same-session concurrent training in elite team sport athletes. In this study, we show that high-intensity interval training before resistance training reduces power output during resistance training but does not impair maximal strength or power development during a 7-week training intervention. The focus of study III was to examine the reliability of isometric leg press and countermovement jump, two commonly used measurements when assessing strength- and power-related variables in elite team sport athletes. In this study, we demonstrate that isometric leg press and countermovement jump are highly reliable measurements when examining strength- and power-related variables.

The findings from study II showed that a reduction in resistance training performance (power output) during same-session concurrent training was visible only when high-intensity interval training was performed before resistance training (study II). The focus of study IV was therefore to investigate the effect of different recovery periods following high-intensity interval training on strength and explosive performance during a power training session in elite team sport athletes. Since isometric leg press and countermovement jump were shown in study III to be highly reliable measurements when assessing strength- and power-related variables in elite team sport athletes, these measurements were used in study IV. In study IV, we demonstrated that high-intensity interval training 10 min prior to power training impairs strength and explosive performance. However, the impairment was no longer present 6 and 24 hours after high-intensity interval training.

In conclusion, the present thesis shows that trained individuals are sensitive to concurrent training, and that adding high-intensity interval training prior to resistance training compromises strength and explosive performance during the resistance training session in elite team sport athletes. However, the reduction in training performance does not seem to translate to reduced strength or power development during shorter training periods (<7-weeks). The findings from the present thesis also show that the reduction in training performance can be reduced by performing the resistance training session first or by allowing at least a 6-hour recovery period between sessions. The findings from this thesis provide a foundation for an evidence-based approach when organizing training to enhance performance in elite team sport athletes, and for future work to further examine the effect of concurrent training on this population.

This study investigates how different recovery periods after high-intensity interval training (HIIT) affects strength and explosive performance during a power training (PT) session. Fifteen female elite ice hockey players (22.5 ± 5.2 years) performed PT, including 6 sets of 2 repetitions (reps) of isometric leg press (ILP) and 6 sets of 3 reps of countermovement jump (CMJ), following a rested state and 10 minutes, 6 hours, or 24 hours after HIIT (3 sets of 8 × 20 seconds at 115% of power output at maximal oxygen consumption on a cycle ergometer). Peak force (PF) and peak rate of force development (pRFD) were measured during the ILP. Peak jump height (PJH), concentric phase duration (ConDur), eccentric phase duration, total duration, peak power (PP), velocity at peak power (V@PP), and force at peak power were measured during CMJ. The following variables were significantly reduced when only a 10-minute recovery period was allowed between HIIT and PT: PF was reduced by 7% (p < 0.001), pRFD by 17% (p < 0.001), PJH by 4% (p < 0.001), ConDur by 4% (p = 0.018), PP by 2% (p = 0.016), and V@PP by 2% (p = 0.007). None of the measured variables were reduced when PT was performed 6 and 24 hours after HIIT. We conclude that strength and explosive performance of elite female ice hockey players is reduced 10 minutes after HIIT but not negatively affected if a rest period of at least 6 hours is provided between HIIT and PT.

Kombinerad styrke- och konditionsträning är vardagsmat för elitidrottare och elitmotionärer. Men personer som tränar mycket är särskilt känsliga för den här träningsformen. Passens ordningsföljd och rätt mängd vila är därför viktigt för att maximera styrkeutvecklingen, visar ny forskning.

Isometric leg press (ILP) and countermovement jump (CMJ) are commonly used to obtain strength- and power-related variables with important implications for health maintenance and sports performance. To enable the identification of true changes in performance with these measurements, the reliability must be known. This study evaluates the between-session reliability of strength- and power-related measures obtained from ILP and CMJ. Thirteen female elite ice hockey players (21.5 ± 5.1 years; 66.3 ± 8.0 kg) performed three maximal ILPs and CMJs on two different occasions. Variables from the ILP (peak force and peak rate of force development) and CMJ (peak power, peak force, peak velocity, and peak jump height) were obtained. The results were reported using the best trial, an average of the two best trials, or an average of three trials. The intraclass correlation coefficient (ICC) and coefficient of variation (CV) were high (ICC > 0.97; CV < 5.2%) for all outcomes. The CV for the CMJ (1.5-3.2%) was lower than that for the ILP (3.4-5.2%). There were no differences between reporting the best trial, an average of the two best trials, or an average of the three trials for the outcomes. ILP and CMJ are highly reliable when examining strength- and power-related variables in elite female ice hockey players.

This study aimed to investigate the effect of intrasession exercise order of maximal effort flywheel resistance training (RT; 436 repetitions [rep]) and high-intensity interval training (HIIT, 2–438 rep of 20 second at 130% of Watt atV̇O2max [wV̇O2max]), on the development of maximal strength and power in elite team-sport athletes. A 7-week training intervention involving 2 training sessions per week of either HIIT followed by RT (HIIT + RT, n 5 8), RT followed by HIIT (RT + HIIT, n 5 8), or RTalone (RT, n 5 7) was conducted in 23 elite male bandy players (24.7 6 4.3 years). Power and work were continuously measured during the flywheel RT. Isometric squat strength (ISq), countermovement jump, squat jump, and V̇O2max were measured before and after the training period. Power output during training differed between the groups (p 5 0.013, h2p5 0.365) with RT producing more power than HIIT + RT (p 5 0.005). ISq improved following RT + HIIT (;80%, d 5 2.10, p 5 0.001) and following HIIT + RT(;40%, d 5 1.64, p 5 0.005), and RT alone (;70%, d 5 1.67, p 5 0.004). V̇O2max increased following RT + HIIT and HIIT + RT(;10%, d51.98, p50.001 resp. d52.08, p50.001). HIIT before RT reduced power output during RT in elite team-sport athletes but did not lead to blunted development of maximal strength or power after a 7-week training period. During longer training periods(.7-weeks), it may be advantageous to schedule RT before HIIT because the negative effect of HIIT + RT on training quality increased during the final weeks of training. In addition, the largest training effect on maximal strength was observed following RT +HIIT.