Effectiveness of high-fat and high-carbohydrate diets on body composition and maximal strength after 15 weeks of resistance training

PURPOSE

The aim of this study was to compare High Carbohydrates Low Fat (HCLF) and Low Carbohydrate High Fat (LCHF) diets in terms of changes in body composition and maximal strength.

PATIENTS/METHODS

The study involved 48 men aged 25 ​± ​2.5, divided into two groups, one of which (n ​= ​23) was following the LCHF diet and the other (n ​= ​25) the HCLF diet. Both groups performed the same resistance training protocol for 15 weeks. Maximal strength in squat, bench press and deadlift was assessed pre- and post-intervention. Measurements of selected body circumferences and tissue parameters were made using the multifunctional, multi-frequency, direct bioelectric impedance InBody 770 analyzer from InBody Co., Ltd (Cerritos, California, USA). The team with the necessary qualifications and experience in research performed all the measurements and maintained participants' oversight throughout the entire length of the study.

RESULTS

Both nutritional approaches were effective in terms of reducing body fat mass. The HCLF group achieved greater skeletal muscle hypertrophy. Significant decreases in body circumferences, especially in the abdominal area, were observed for both dietary approaches. Maximal strength significantly increased in the HCLF group and decreased in the LCHF group.

CONCLUSION

Holistic analysis of the results led to the conclusion that both dietary approaches may elicit positive adaptations in body composition. The two approaches constitute useful alternatives for both recreational exercisers and physique athletes with body composition goals.

The Connection Between Resistance Training, Climbing Performance, and Injury Prevention

BACKGROUND

Climbing is an intricate sport composed of various disciplines, holds, styles, distances between holds, and levels of difficulty. In highly skilled climbers the potential for further strength-specific adaptations to increase performance may be marginal in elite climbers. With an eye on the upcoming 2024 Paris Olympics, more climbers are trying to maximize performance and improve training strategies. The relationships between muscular strength and climbing performance, as well as the role of strength in injury prevention, remain to be fully elucidated. This narrative review seeks to discuss the current literature regarding the effect of resistance training in improving maximal strength, muscle hypertrophy, muscular power, and local muscular endurance on climbing performance, and as a strategy to prevent injuries.

MAIN BODY

Since sport climbing requires exerting forces against gravity to maintain grip and move the body along the route, it is generally accepted that a climber`s absolute and relative muscular strength are important for climbing performance. Performance characteristics of forearm flexor muscles (hang-time on ledge, force output, rate of force development, and oxidative capacity) discriminate between climbing performance level, climbing styles, and between climbers and non-climbers. Strength of the hand and wrist flexors, shoulders and upper limbs has gained much attention in the scientific literature, and it has been suggested that both general and specific strength training should be part of a climber`s training program. Furthermore, the ability to generate sub-maximal force in different work-rest ratios has proved useful, in examining finger flexor endurance capacity while trying to mimic real-world climbing demands. Importantly, fingers and shoulders are the most frequent injury locations in climbing. Due to the high mechanical stress and load on the finger flexors, fingerboard and campus board training should be limited in lower-graded climbers. Coaches should address, acknowledge, and screen for amenorrhea and disordered eating in climbers.

CONCLUSION

Structured low-volume high-resistance training, twice per week hanging from small ledges or a fingerboard, is a feasible approach for climbers. The current injury prevention training aims to increase the level of performance through building tolerance to performance-relevant load exposure and promoting this approach in the climbing field.

Handgrip strength asymmetry as a new biomarker for sarcopenia and individual sarcopenia signatures

BACKGROUND

Although handgrip strength (HGS) asymmetry has clinical screening utility, its relevance to sarcopenia is unknown. This study examined the relationship between HGS asymmetry and sarcopenia signatures, and explored the relevance of circulating neural/neuromuscular markers.

METHODS

9403 individuals aged 18-92 years participated in this study. Maximal HGS and skeletal muscle index (SMI) were determined using hand dynamometry and DXA. Sarcopenia was diagnosed upon the presence of low HGS and low SMI, according to cohort-specific thresholds. Plasma biomarkers were measured by ELISA in a sub-group of 269 participants aged 50-83 years. Asymmetry was determined as the highest recorded HGS divided by the highest recorded HGS of the opposite hand. Individuals with a ratio > 1.10 were classified as having asymmetrical HGS.

RESULTS

Subjects with asymmetrical HGS had significantly lower SMI (7.67 kg/m2 vs 7.71 kg/m2, p = 0.004) and lower HGS (37.82 kg vs 38.91 kg, p < 0.001) than those with symmetrical HGS. In those aged ≥ 50 years asymmetrical HGS was associated with 2.67 higher odds for sarcopenia [95% confidence interval: (CI) = 1.557-4.561, p < 0.001], 1.83 higher odds for low HGS only (CI 1.427-2.342, p < 0.001), and 1.79 higher odds for low SMI only (CI 1.257-2.554, p = 0.001). HGS asymmetry demonstrated acceptable diagnostic accuracy for sarcopenia (AUC = 0.727, CI 0.658-0.796, p < 0.001). Plasma neural cell adhesion molecule concentrations were 19.6% higher in individuals with asymmetrical HGS (185.40 ng/mL vs 155.00 ng/mL, p < 0.001) than those with symmetrical HGS.

DISCUSSION

Our findings demonstrate the utility of HGS asymmetry as a screening tool that may complement existing strategies seeking to combat sarcopenia. Biomarker analyses suggest that heightened denervation may be an important aetiological factor underpinning HGS asymmetry.

Adaptive changes in bodybuilders in conditions of different energy supply modes and intensity of training load regimes using machine and free weight exercises

Background

The research was aimed at comparing the effect of using two types of training load different in intensity and energy supply. We studied the influence of the proposed load variations (machine and free weight exercises) on long-term adaptation of the body at the stage of specialized basic training in bodybuilding.

Methods

A total of 64 athletes aged 18-20 years were examined. The research participants were randomly divided into four groups, 16 athletes in each group. Athletes of group 1 and 3 used a complex of free weight exercises. Group 2 and 4 participants performed machine exercises. Bodybuilders of group 1 and 2 were trained in conditions of medium intensity training load (R _a  = 0.58) in the anaerobic-glycolytic mode of energy supply. Athletes of the 3rd and 4th groups used high intensity load (R _a  = 0.71) in the anaerobic-alactate mode of energy supply. We managed to determine the nature of adaptation processes using methods of control testing of strength capabilities, bioimpedansometry, anthropometry, biochemical analysis of blood serum (LDH, creatinine).

Results

The study showed that the difference in the dynamics of the participants' maximum strength development (on example of chest muscles) did not depend on the content of machine or free weight exercises, but on the features of training load regimes. Thus, the controlled indicator of strength capabilities in athletes of groups 3 and 4 increased by 5.1% compared to groups 1 and 2. During all stages of the study, the indicators of the projectile working mass in athletes of groups 3 and 4 exceeded the results observed in groups 1 and 2 by 25.9%. At the same time, the amount of load in a set is on average 2 times higher in athletes of groups 1 and 2. Group 4 athletes, who used machine exercises and high intensity training load, increased the circumferential body measurements by 3.8 times (the chest), compared to the results recorded in group 1 athletes. Athletes of group 1 and 2 showed increasing in body fat by 3.4% compared to the initial level on the background of large load volume. The basal creatine level in bodybuilders of groups 3 and 4 increased by 3.7 times after 12 weeks of study, which indicates an accelerated growth of muscle mass.

Conclusion

The most pronounced adaptive body changes in bodybuilders at the stage of specialized basic training occurred during high intensity training load and anaerobic-alactate energy supply mode. Machine exercises contributed to increasing the morpho functional indicators of athletes more than free weight exercises.

Effects of motor imagery training on skeletal muscle contractile properties in sports science students

Background

Studies on motor imagery (MI) practice based on different designs and training protocols have reported changes in maximal voluntary contraction (MVC) strength. However, to date, there is a lack of information on the effects of MI training on contractile properties of the trained muscle.

Methods

Forty-five physically active sport science students (21 female) were investigated who trained three times per week over a 4-week period in one of three groups: An MI group conducted MI practice of maximal isometric contraction of the biceps brachii; a physical exercise (PE) group physically practiced maximal isometric contractions of the biceps brachii in a biceps curling machine; and a visual imagery (VI) group performed VI training of a landscape. A MVC test of the arm flexors was performed in a biceps curling machine before and after 4 weeks of training. The muscular properties of the biceps brachii were also tested with tensiomyography measurements (TMG).

Results

Results showed an interaction effect between time and group for MVC (p = 0.027, η ² = 0.17), with a higher MVC value in the PE group (Δ5.9%) compared to the VI group (Δ -1.3%) (p = 0.013). MVC did not change significantly in the MI group (Δ2.1%). Analysis of muscle contractility via TMG did not show any interaction effects neither for maximal radial displacement (p = 0.394, η ² = 0.05), delay time (p = 0.79, η ² = 0.01) nor contraction velocity (p = 0.71, η ² = 0.02).

Conclusion

In spite of MVC-related changes in the PE group due to the interventions, TMG measurements were not sensitive enough to detect concomitant neuronal changes related to contractile properties.

Interindividual variability of adaptations following either traditional strength or power training combined to endurance training in older men: A secondary analysis of a randomized clinical trial

This study aimed to investigate the interindividual responses following two different concurrent training (CT) regimens in neuromuscular, cardiorespiratory and functional outcomes of older men. Thirty-five older men (65.8 ± 3.9 years) were randomly allocated into one of two CT groups: power training (PT) + high-intensity interval training (HIIT) (n = 17); or traditional strength training (TST) + HIIT (n = 18). Maximal dynamic strength (one-repetition maximum, 1RM), rate of force development at 100 milliseconds (RDF₁₀₀), countermovement jump power (CMJ), quadriceps femoris muscle thickness (QF MT), functional tests (sit-to-stand, timed-up-and-go, and stair climbing), and peak oxygen consumption (VO_2peak) were assessed pre-, post-8 and post-16 weeks of training. The Chi-squared test was used for assessing differences in the prevalence of responders (Rs), non-responders (NRs), and adverse responders (ARs). Similar prevalence of individual responses (Rs, NRs and ARs) between groups were observed after intervention in almost all outcomes: 1RM; power at CMJ; QF MT, and functional tests (P > 0.05). However, a significant difference in the distribution of Rs, NRs and ARs between groups was observed in the RFD₁₀₀ after 16 weeks (p = 0.003), with PT + HIIT group presenting high prevalence of Rs than TST + HIIT (100 % vs. 50 %). The inclusion of explosive-type of contractions in a concurrent training regime induces greater responsiveness in the RFD₁₀₀ in older men, while no differences compared to traditional strength training are observed in maximal strength, muscle size, VO_2peak, and functional performance.

Physical Health Impairment and Exercise as Medicine in Severe Mental Disorders: A Narrative Review

BACKGROUND

Individuals with severe mental disorders (SMDs; schizophrenia spectrum disorders, bipolar disorder, and major depressive disorder) are not only suffering from their mental conditions; they also have an attenuated physical health, augmenting their overall critical condition.

OBJECTIVES

We review and critically appraise the evidence based on (1) key physiological factors relating to aerobic endurance and skeletal muscle strength; (2) implications for physical function and health; and (3) effects of training interventions with different intensities evaluated in individuals with SMDs.

FINDINGS

Reductions in aerobic endurance factors, peak oxygen uptake (VO_2peak) and walking work efficiency, are paralleled by reductions in maximal skeletal muscle strength and power. In turn, the poor aerobic endurance and muscle strength lead to impaired physical function, increased risk of lifestyle-related diseases, and ultimately early death. Exercise has the potential to counteract the attenuated physical health in people with SMDs. While aerobic endurance training is shown to increase VO_2peak due to plasticity of the oxygen transport system, strength training is documented to improve maximal muscle strength, power, and walking work efficiency as a result of adaptations in neuromuscular force developing factors.

CONCLUSIONS

In conclusion, improvements in these key determinants for physical health appear to be achievable in people with SMDs despite many being challenged by motivational difficulties with attending regular exercise and have beneficial implications for physical function during activities of daily living, lifestyle-related diseases, and early death.

Chronic Effects of Heavy Load Activity Performed Before Resistance Training Sessions on the Physical Performance of Youth Soccer Players

The adoption of resistance training (RT) programs has been shown to positively influence sports performance-related parameters. However, the chronic effects of maximal strength protocols on the performance of soccer players are not completely investigated. The aim of this study was to evaluate the effects of performing two repetition maximum (2RM) before a resistance training session on the physical performance of youth soccer players. Seventeen players (under-20 category) were allocated in one of the following groups: 2RM + resistance training group (2RM + RT, n = 8) and resistance training group (RTG, n = 9). Both groups performed the same RT protocol during experimental weeks. However, the 2RM + RT performed 1 set of 2RM for 4 exercises, previously to RT protocol. Pre and post intervention period, one repetition maximum of the back squat exercise (1RM_SQUAT), sprint time (15m-sprint test), countermovement jump (CMJ), repeated sprint ability (RSA_BEST and RSA_MEAN), and yo-yo intermittent recovery test level-2 (YYIRT2) were assessed. Total load lifted (TLL) during the experimental weeks was also collected. Significant increases in 1RM_SQUAT (2RM + RT: +45.1%, d = 4.40; RTG: +32.3%, d = 1.84), 15m sprint (2RM + RT: -9.0%, d = 7.9; RTG: -8.8%%, d = 3.2), CMJ (2RM + RT: +2.3%, d = 0.17; RTG: +0.8%, d = 0.07), RSA_BEST (2RM + RT: -2.4%, d = 0.6; RTG: -2.3%, d = 1.04), RSA_MEAN (2RM + RT: -2.9%, d = 1.33; RTG: -3.4%, d = 1.78), YYIRT2 (2RM + RT: +12.0%, d = 0.82; RTG: +12.1%, d = 0.63) (all p < 0,05) were observed for both groups on pre to post-intervention periods, with no significant difference between groups. Therefore, the 2RM + RT protocol did not promote additional increase on performance of young soccer players.

Leg press and chest press strength normative values by half-decades in older persons

Evaluating muscular strength is vital to the application of effective training protocols that target quality of life and independence in older individuals. Resistance training is a valuable tool to improve functional capacity, strength, and power in this population; however, the lack of normative values for common lifts such as the leg press (LP) and chest press (CP) reduce its utility. This study developed age- and sex-specific normative strength values for older individuals. LP and CP 1-repetition maximum (1RM) values on Keiser A420 pneumatic machines were compiled from 445 older adults, ages 60-85y. Descriptive statistics and quartile rankings are reported, and two-way ANOVAs were conducted to determine differences between sex and age groups. There were significant sex x age group interactions for LP and CP. Men were significantly stronger than women across all age groups for both exercises (p < .01); however, the mean difference decreased with age. For men, no differences were seen among the 60-64 (237 ± 39 kg), 65-69 (223 ± 43 kg) and 70-74 (219 ± 50 kg) age groups; but the 60-64 group showed higher strength values than the 75-79 group (193 ± 52 kg) and all three groups contained higher strength values than the 80-85 group (172 ± 40 kg). Similarly, for relative strength, the 60-64 group (2.80 ± 0.53 kg·kgBM) surpassed values for all groups but the 65-69, and the 65-69 (2.70 ± 0.54 kg·kgBM) produced greater strength values than the 70-74 (2.45 ± 0.47 kg·kgBM), 75-79 (2.09 ± 0.37 kg·kgBM) and 80-85 (2.19 ± 0.38 kg·kgBM) groups. In contrast, no significant differences in absolute or relative strength were seen among age groups for the women. Our study establishes absolute and relative age- and sex-specific normative values for the LP1RM and CP1RM in older individuals. These values allow practitioners and researchers to interpret the results of various interventions, and evaluate their importance to evaluation of sarcopenia, injury risk, functional mobility and quality of life. Additionally, our results reveal that age-related declines in strength are prominent for male LP and CP, but not female CP or LP.

Effects of subjective and objective autoregulation methods for intensity and volume on enhancing maximal strength during resistance-training interventions: a systematic review

Background

Maximal strength is a critical determinant of performance in numerous sports. Autoregulation is a resistance training prescription approach to adjust training variables based on the individuals’ daily fluctuations in performance, which are a result of training-induced fitness and fatigue, together with readiness from daily non-training stressors.

Objective

This review aimed to summarise the effects of different subjective and objective autoregulation methods for intensity and volume on enhancing maximal strength.

Materials and Methods

A comprehensive literature search was conducted through SPORTDiscus, PubMed and Google Scholar. Studies had to meet the following criteria to be included in the review: (1) estimation of 1-RM or a 1-RM test for both pre-test and post-test to measure progression in strength assessment during the training intervention, (2) a training comparison group, (3) participants were healthy, (4) the article had a detailed description of training intensity, training volume, and training frequency during the training intervention, (5) the training intervention lasted for more than four weeks, (6) studies with objective autoregulation methods utilised a validated measuring tool to monitor velocity, (7) English-language studies.

Results

Fourteen studies met the inclusion criteria, comprising 30 training groups and 356 participants. Effect size and percentage differences were calculated for 13 out of 14 studies to compare the effects of different training interventions. All autoregulation training protocols resulted in an increase in 1-RM, from small ES to large ES.

Conclusion

Overall, our findings suggest that using both subjective autoregulation methods for intensity, such as repetitions in reserve rating of perceived exertion and flexible daily undulation periodisation, together with objective autoregulation methods for autoregulation intensity and volume, such as velocity targets and velocity loss, could be effective methods for enhancing maximal strength. It is speculated that this is because the implementation of autoregulation into a periodised plan may take into account the athletes’ daily fluctuations, such as fluctuations in fitness, fatigue, and readiness to train. When training with a validated measuring tool to monitor velocity, this may provide objective augmented intra- and interset feedback during the resistance exercise who could be beneficial for increasing maximal strength. Coaches, practitioners, and athletes are encouraged to implement such autoregulation methods into a periodised plan when the goal is to enhance maximal strength.

Force decline after low and high intensity contractions in persons with multiple sclerosis

OBJECTIVE

Force decline during strong contractions is dominated by changes in the periphery whereas during weaker contraction changes in voluntary activation become more important. We compared force decline and contributing factors in persons with multiple sclerosis (PwMS) during low and high intensity contractions.

METHODS

Index finger abduction force, force evoked by electrical stimulation of the ulnar nerve at rest (RTw), and during MVCs were investigated in 19 PwMS and 19 controls. Participants performed contractions in sets of six contractions (7 s-on, 3 s-off) at 25% or 80% MVC. After each set, a 5 s-MVC was performed with superimposed nerve stimulation followed by RTw. Contractions were repeated until MVC dropped below 80% of initial MVC.

RESULTS

Low compared to high intensity contractions caused a greater decline in voluntary activation and a smaller decline in RTw. Compared to controls, PwMS accomplished equal sets of contractions but showed a smaller decline in RTw. Female PwMS showed poorer voluntary activation. The number of low intensity contractions was associated with sense of fatigue in PwMS.

CONCLUSION

Although, no difference in fatigability was observed, the mechanism contributing to force decline differed between PwMS and controls during submaximal contractions.

SIGNIFICANCE

During weak contractions, fatigue and fatigability are associated in PwMS.

Female maximal push/pull strength capabilities by humeral abduction angle in bilateral exertions

Pushing or pulling an object constitutes the majority of manual materials handling tasks. Anthropometric differences between workers alter pushing and pulling strategies at fixed heights, potentially modifying exposures and causing overexertion. Capability normalized to arm posture rather than work height remains unknown, and the purpose of this research was to quantify maximal pushing and pulling strength and upper extremity joint moments using fixed humeral abduction angles and a flexed arm position. Twenty university-aged females completed maximal pushes and pulls at 0°, 30°, 60°, 90°, and 120° of humeral abduction with an elbow to 90°. Abduction angle was the largest modifier of both push and pull force generating capability (p < 0.01), with increasing abduction reducing force capability by up to 30%. While push exertions on average exceeded pulls by 17 N (p < 0.01), the difference is much smaller than previous reports. Ergonomists should consider humeral angle of the worker rather than work heights, as individuals working in increased abduction decreases capability and increases potential overexertion injury risk.

Relation between Peak Power Output in Sprint Cycling and Maximum Voluntary Isometric Torque Production

From a cycling paradigm, little has been done to understand the relationships between maximal isometric strength of different single joint lower body muscle groups and their relation with, and ability to predict PPO and how they compare to an isometric cycling specific task. The aim of this study was to establish relationships between maximal voluntary torque production from isometric single-joint and cycling specific tasks and assess their ability to predict PPO. Twenty male trained cyclists participated in this study. Peak torque was measured by performing maximum voluntary contractions (MVC) of knee extensors, knee flexors, dorsi flexors and hip extensors whilst instrumented cranks measured isometric peak torque from MVC when participants were in their cycling specific position (ISOCYC). A stepwise regression showed that peak torque of the knee extensors was the only significant predictor of PPO when using SJD and accounted for 47% of the variance. However, when compared to ISOCYC, the only significant predictor of PPO was ISOCYC, which accounted for 77% of the variance. This suggests that peak torque of the knee extensors was the best single-joint predictor of PPO in sprint cycling. Furthermore, a stronger prediction can be made from a task specific isometric task.

Acute effects of stretching on maximal muscle strength and functional performance: A systematic review of Japanese-language randomised controlled trials

BACKGROUND

There is no consensus in the English-language literature regarding the best types or dosages of stretching to maximise muscle strength and functional performance. It is possible that primary research published in non-English languages provides different insights, and could add to the body of international knowledge.

PURPOSE

This systematic review aimed to identify and evaluate Japanese-language randomised controlled trials (RCTs) investigating acute effects of stretching on maximal strength and functional performance.

METHODS

Three Japanese databases and five English databases were searched from inception to 24 March 2015. Only Japanese-language RCTs examining acute effects of stretching on maximal strength and/or functional performance were included. Risk of bias in included studies was assessed using Physiotherapy Evidence Database scale. GRADE (Grading of Recommendation Assessment, Development and Evaluation) approach was applied to evaluate the quality of evidence. Descriptive synthesis was attempted.

RESULTS

Seven RCTs with variable methodological quality were included. No two studies were the same, thus meta-analysis was not possible. Descriptively, because of heterogeneity of interventions and outcome measures, it was not possible to identify consensus on the benefits of stretching. GRADE approach indicated low to very low quality evidence for this topic.

CONCLUSION

This review of Japanese-language RCTs provided no additional information to strengthen or challenge the current English-language evidence base on acute effects of stretching on maximal strength and performance. Future Japanese-language studies should address methodological flaws exposed in this review and incorporate functional outcome measures to strengthen the international evidence base.

Strength and size relationships of the quadriceps and hamstrings with special reference to reciprocal muscle balance

PURPOSE

This study examined the association of muscle size and strength for the quadriceps and hamstrings, the relationship between the size of these muscles, and whether the H:Q size ratio influenced reciprocal strength balance-widely regarded as a risk factor for hamstrings injury.

METHODS

Knee extensor and flexor isometric, concentric and eccentric (50 and 350° s(-1)) strength were measured in 31 healthy, recreationally active young men. Muscle volume was measured with magnetic resonance imaging.

RESULTS

The knee flexors achieved higher concentric and eccentric torques (normalised to isometric values) than the extensors. Muscle volume explained a significant part of the inter-individual differences in strength in both extensors (isometric 71%, concentric 30-31%) and flexors (isometric 38%, concentric 50-55%). Notably, muscle size was related to knee flexor eccentric strength (r = 0.69-0.76; R (2) = 48-58%) but not extensor eccentric strength. Quadriceps and hamstrings volumes were moderately correlated (r = 0.64), with the majority of the variance in the size of one muscle (59%) not explained by the size of the other muscle. The hamstrings-to-quadriceps (H:Q) volume ratio was correlated with the isometric (r = 0.45) and functional strength ratios (350° s(-1), r = 0.56; 50° s(-1), r = 0.34).

CONCLUSIONS

Muscle size exhibited a differential influence on knee extensor and flexor eccentric strength. Quadriceps and hamstrings muscle size was related, and the H:Q size ratio contributed to their strength ratios. Muscle size imbalances contribute to functional imbalances and these findings support the use of hamstrings strength training with an emphasis on hypertrophic adaptations for reducing injury risk.

The effects of heavy upper-body strength training on ice sledge hockey sprint abilities in world class players

The current study investigated the effects of 6 weeks of heavy upper-body strength training on maximal strength and sprint abilities in eight world class ice sledge hockey players. Before and after the strength training intervention, all subjects performed a 30-m maximal sprint on ice (where time for each 10 m section was measured) and 1 repetition maximal (1RM) strength test in the bench pull (BP), pull-down (PD), pull over (PO) and front pull (FP) exercises. Three weekly sessions with 3×6-8RM for these strength exercises were added during the intervention period. From pre- to post-test, 1RM in the strength exercises improved by 4-8%, whereas 30-m sprint time, all 10-m section times and the calculated power output in the 10-m acceleration phase all improved by 2-3% (all P<.05). The pre- to post-test changes in 30-m sprint time and the initial 10-m time correlated significantly with the changes in 1RM for BP (r=0.59 and 0.55) and PD (r=0.60 and 0.68) (all P<.05). In conclusion, the results of this study strongly suggest that heavy upper-body strength training improves upper-body strength and ice sledge hockey sprint abilities, and that the magnitude of improvements in strength correlates with the improvements in sprint abilities.