Abstract
hletes competing in distance competitions have used a combination of aerobic and anaerobic training approaches to train and enhance the performance-determining elements. Nevertheless, few studies have reported data related to the effect of concurrent training on well-trained distance (3,000 m – 10,000 m) runners. Because of limited evidence available for this population, this study aimed to investigate the effect of concurrent strength and endurance training on distance running performance. A randomized study was conducted. Thirty-nine distance runners (16.62±0.71 years) were randomly assigned into the endurance training group (ETG; n=13), strength training group (STG; n=13), and concurrent training group (CTG; n=13). The 12 weeks of training in which each group trained 3 times a week. The participants were tested on 1RM squat test, push-up test, VO2 max, and 5-km time trial. Findings showed that STG significantly higher than ETG enhancements on 1RMsquat (p<0.001) and push-up (p<0.001) and STG signifi- cantly higher than CTG enhancements on 1RM squat (p<0.001), push up (p=0.045). ETG results were significantly better than those obtained by STG on VO2 max (p=0.002) and 5-km time trial (p=0.004). Finally, the improvements obtained by CTG were significantly higher than those attained by ETG on 1RM squat (p<0.001), push-up (p<0.001); VO2 max (p<0.001) and 5-km time trial (p=0.002). In conclusion, performing 12-week concurrent training program improves performance variables that can be obtained with strength and endurance training in long-distance running. Athletes can acquire strength and endurance adaptations by engaging in concurrent training regimens. Keywords: aerobic training, muscle strength, physiological performance, resistance training Introduction Distance running performance is the consequence of a complex interaction of physiological and physical factors and it is dominated by combinations of strength, speed, endurance, flexibility, and coordination (Blagroveet al., 2018). Athletes competing in distance events have improved performance-de- termining factors using a combination of aerobic and anaer- obic training methods (Berryman
training, muscle strength, physiological performance, resistance training Introduction Distance running performance is the consequence of a complex interaction of physiological and physical factors and it is dominated by combinations of strength, speed, endurance, flexibility, and coordination (Blagroveet al., 2018). Athletes competing in distance events have improved performance-de- termining factors using a combination of aerobic and anaer- obic training methods (Berryman et al., 2017). Furthermore, due to the nature of the competition schedule or training time available distance running often performs a combination of endurance training and strength training on the same day (Enright et al., 2017). There is growing evidence that concur- rent strength and endurance training improves running per- formance more than endurance training alone, even though the factors that determine distance running performance have historically been established by aerobic running training (Blagrove, Howatson, & Hayes, 2018). According to a thorough systematic evaluation, concur- rent strength and endurance training has a moderately posi- tive impact on middle and long-distance time trials up to 10 km (Blagrove et al., 2018). The effect of concurrent training has been widely investigated by researchers. Some of them provide strong evidence that after concurrent training inter- vention muscle hypertrophy, strength, and power adaptations Correspondence: A.W. Demeku Bahir Dar University, Department of Sport Science/Sports Academy, Bahir Dar, 79, Ethiopia E-mail:melkamdemeku24@gmail.com ORIGINAL SCIENTIFIC PAPER
102 Sport Mont 21 (2023) 3CONCURRENT STRENGTH AND ENDURANCE TRAINING | D. A. WONDEM & Z. M. TEGEGNE were mostly attenuated, compared with those after isolated strength training stimuli (Tsitkanou et al., 2017). Conversely, Boullosa et al. (2020), and Ferrari et al. (2021) stated that com- bining training strength and cardiorespiratory fitness with strength in a training cycle could increase performance more than single-mode training. In the word of Piacentini et al. (2013), endurance athletes benefit from concurrent strength and endurance training because the rate of force production, one of the key factors of endurance performance, is critical for running. There have been numerous research investigations looking into the function of maximal oxygen consumption (VO2max) in distance running. In heterogeneous groups, research has demonstrated a substantial correlation between VO2max and middle-distance (800 m, r=0.75) and long-distance (marathon, r=0.78) performance (Ingham et al., 2008; Beattie et al., 2017). Another study also showed eight weeks of con - current strength and endurance training has beneficial ef- fects on musculoskeletal power, maximal oxygen uptake, and the record level of running time (Saud & Nabia, 2016). Significantly, the majority of past studies on concurrent training have concentrated on confirming the compatibility of concurrent strength and endurance training. And research findings are sometimes ambiguous in this area, and it is still unclear how useful strength training is for endurance ath - letes. Consequently, this study investigated the effects of 12 weeks of concurrent strength and endurance training on the performance of long-distance running. This study expect - ed that concurrent training may have significant effect on long-distance running performance. So, this study examined the effect of strength, endurance, and concurrent training on the performance of long-distance running. Methods Study design and participants A randomized study was conducted. Using random sam- pling select 39 well-trained distance runners (3,000 m – 10,000 m) from the Tilili athletics center. After being informed of the benefits and potential risks of the investigation, partic- ipants were randomized into three groups based on their 5km running time; Endurance training group (ETG) (n=13; 16.7±0.8 years; 57.77±2.29 kg (kilogram); 1.72±0.05 m (me- ter)),
was conducted. Using random sam- pling select 39 well-trained distance runners (3,000 m – 10,000 m) from the Tilili athletics center. After being informed of the benefits and potential risks of the investigation, partic- ipants were randomized into three groups based on their 5km running time; Endurance training group (ETG) (n=13; 16.7±0.8 years; 57.77±2.29 kg (kilogram); 1.72±0.05 m (me- ter)), Strength training group (STG) (n=13; 16.62±0.86 years; 56.42±2.01 kg; 1.72±0.05 m) and Concurrent training group (CTG) (n=13; 16.55±0.686 years; 56.96±2.24 kg; 1.717±0.06 m). Participants in the study had an average training back- ground of at least 2 years. All experimental procedures were ratified by the Bahir Dar University, Sports Academy Research Ethics Committee (No. ERC 01/2022). In addition, all participants in this research had to provide written informed consent.To investigate the effect of concurrent strength and endurance training intervention on strength qualities, physiological indicators, and a 5km time record of long-distance running; the researchers collect- ed quantitative data through appropriate field tests measures such as the Cooper VO2 max test, push-up test, 1RM squat test, and 5km time trial. Training protocol Athletes were kept in a training log, which included any physical activity done outside of the training program. All training sessions were coached by an experienced coach. Each strength session lasted approximately sixty minutes. The train- ing program lasted 12 weeks, with study participants attending three non-consecutive sessions per week. The training inter- ventions took place from the beginning of September to the end of November 2022. Strength training The training sessions included squat, leg curl, triceps ex- tension, bench press, calf raise, trunk extension, pulldown, hurdle hops, extended bounds, and uphill running per - formed. There are rests between sets and between exercises. This training program is performed by STG. A more detailed description of the strength training program is presented in Table 1. Table 1. Training Methodology that Was Used Within STG Week Training Parameters Exercises I (% 1RM)S (No)RepDi (Km)Incl (%)RTS (′)RTR (′) 1Squat, Leg Curl, Triceps Extension 60 4 14 2 2Squat, Bench Press, Calf Raise 65 4 12 2 3Trunk Extension, Leg Curl, Calf
by STG. A more detailed description of the strength training program is presented in Table 1. Table 1. Training Methodology that Was Used Within STG Week Training Parameters Exercises I (% 1RM)S (No)RepDi (Km)Incl (%)RTS (′)RTR (′) 1Squat, Leg Curl, Triceps Extension 60 4 14 2 2Squat, Bench Press, Calf Raise 65 4 12 2 3Trunk Extension, Leg Curl, Calf Raise 70 5 12 2 4Squat, Leg Curl, Pulldown 75 5 10-8 3 5Squat, Bench Press, Calf Raise 80 4 8-6 3 6Squat, Bench Press, Calf Raise 90 4 8 3 7 Squat + Hurdle Hops + 2′30″ Running at 100% Of MAS 80 66+10 5 8Squat + Hurdle Hops + 2′30″ Running 82 65+10 5 9 Squat + Extended Bounds (Cover 50 M Alternating Legs by Doing the Lowest Possible Number of Strides) + 2′15″ Running. 84+105 6 4 5 10 Squat + Extended Bounds (Cover 50 M Alternating Legs by Doing the Lowest Possible Number of Strides) + 2′ Running 86+110 6 3 5 11Uphill Running 115 3 5 0.2 6 10 3 12Uphill Running 120 2 5 0.2 6 10 3 Notes: 1RM: One-repetition maximum; Di: Distance; Incl: Inclination; Km: Kilometer;MAS:Maximume average speed; No: Number, Rep: Repetitions; RTR:Resting time between reps; RTS: Resting time between sets; S: Sets; STG: strength training group
CONCURRENT STRENGTH AND ENDURANCE TRAINING | D. A. WONDEM & Z. M. TEGEGNE Sport Mont 21 (2023) 3 103 Endurance training The main components of endurance training (see table 2) were continuous exercise lasting 45–50 minutes, Fartlek for 40–60 minutes, and reputation training. The amount of time devoted to endurance training and how this time was distributed throughout the training zones were the same across endurance-only training groups and concurrent training groups. Table 2.Training Methodology that Was Used Within ETG Week Training Parameters Exercises I (b.p.m) Du (′) Rep (No)Di(km) RT (′) 1 Continuous Training 130–140 45 2 Continuous Training 140–144 50 3 Continuous Training 145–150 45 4 Fartlek Training. 115–160 50 5 Fartlek Training. 115–160 55 6 Fartlek Training. 115–160 60 7 Extensive Interval Training (Long Intervals)155–160 3 10 2 8 Extensive Interval Training (Long Intervals)160–165 2 10 2 9 Extensive Interval Training (Long Intervals)165–170 1 14 2 10 Repetition Training 180 3 5 8 11 Repetition Training 185 2 5 6 12 Competition 100 1 5 Notes: b.p.m: beat per minute; Di: distance; Du: Duration; ETG: Endurance training group;I: Intensity of training; Km: kilometer; No: Number; Rep: Repetition; RT: Resting Time Concurrent training The concurrent training group (CTG) performed both strength and endurance programs on the same day, in which the endurance sessions are performed first and after 8-hour rest followed by the strength session. The training program of CTG included the same strength exercises as STG and ETG. Assessments To reduce the impact of extraneous factors and tidal variation on outcome measurements, many control proce - dures were put in place. The participants were instructed to continue living their regular lives, eating their regular meals, and refraining from using any nutritional supplements during the intervention time. After 12 weeks of training, each participant completed a familiarization before physical and physiological tests. After a 48-hour rest period, the lead researcher gave a thorough explanation of the testing proce - dures. Then before and after the 12-week training program, some anthropometric and physiological parameters were assessed (pretest and posttest). Before beginning the tests, a warm-up was carried out; running
12 weeks of training, each participant completed a familiarization before physical and physiological tests. After a 48-hour rest period, the lead researcher gave a thorough explanation of the testing proce - dures. Then before and after the 12-week training program, some anthropometric and physiological parameters were assessed (pretest and posttest). Before beginning the tests, a warm-up was carried out; running for 10 minutes at 60% of one's theoretical maximum heart rate, followed by five min - utes of joint mobility activities which serve as the general warm-up. The participant’s body weight, age, and height were all tak- en into consideration. A Seca digital column scale, model 769, was used to measure body weight (Hamburg, Germany). 1RM squat test was used to assess lower body maximum strength. Participants were instructed to maintain a naturally upright trunk position throughout the assessment. Both hands were securely gripping the bar, which was also being supported by the shoulders. The performer's legs were parallel to the ground when the test began with their knees bent 90 degrees. The subjects then stood up straight with their legs completely extended. Each subject needed between two and four tries to determine their 1RM. Only completed efforts were recorded. Between each trial, there was a three-minute break. An other test was push-up test; a standard push-up be- ginning with the hands and toes on the floor, the body and legs in a straight line, feet spaced slightly apart, and the arms outstretched, shoulder width apart, and at a right angle to the torso. The individual lowers their body while maintaining a straight back and knees to a predefined point, to another ob- ject, or until their elbows are at a 90-degree angle, then raises their arms back up to their starting positions. The test contin- ues until tiredness until they can no longer perform them in rhythm, or until they have completed the required number of pushups (Saud & Nabia, 2016). To determine the VO2 max, Cooper's 12-minute run test was employed. Cooper's 12-minute run test should be ap - plied with the newly calculated norm as a viable
their starting positions. The test contin- ues until tiredness until they can no longer perform them in rhythm, or until they have completed the required number of pushups (Saud & Nabia, 2016). To determine the VO2 max, Cooper's 12-minute run test was employed. Cooper's 12-minute run test should be ap - plied with the newly calculated norm as a viable approach for accurate, correct, and precise assessment of cardiore - spiratory fitness in terms of VO2 max (Bandyopadhyay, 2015). The subjects were run for a total of 12 minutes on a 400-meter circular track. The number of completed laps was counted, and the finish line was marked. By dividing the number of complete laps by 400 and adding the distance (in meters) of the final incomplete loop, one may compute the total distance (in meters) traveled in 12 minutes. The follow - ing equation was used to predict the VO2 max and convert the distance in meters to kilometers. VO2 max (ml · kg−1 · min−1) = (22.351 × distance covered in kilometers) − 11.288 (Meredith & Welk, 2010). The running test of choice was a 5-kilometer time tri- al. Only dry circumstances and winds below 2 m/s were used during testing (Karsten et al., 2016). A 5-kilometer run on a 400-meter outdoor running track was performed after a 10-minute warm-up at a self-determined pace. Participants were instructed to give it their all during the 5-km time trial. Completion times were noted to the nearest second.
104 Sport Mont 21 (2023) 3CONCURRENT STRENGTH AND ENDURANCE TRAINING | D. A. WONDEM & Z. M. TEGEGNE Statistical analysis Descriptive statistical analysis was made to display means (M) and standard deviation (SD). Levene's test was used to confirm the homogeneity of variances, and the Shapiro-Wilk test was performed to compare the normality of the variables. To confirm the performance differences between groups, a one-way ANOVA test was used. A two-way repeated-mea - sure ANOVA was then conducted to evaluate the training effects on the physical and performance characteristics be - tween groups (ETG vs. STG vs. CTG) and within groups (pre-test vs. post-test). When statistically significant p-values were found, post hoc multiple comparisons with Bonferroni correction were used to identify those differences (group- by-time interaction effect or main effects of time or group). To check the consistency between the pre-test and post-test measures, the interclass correlation coefficient (ICC) was cal - culated for each of the examined performance factors. Low ICC=0.49, moderate ICC=0.50, high ICC=0.75, and remark - able ICC=0.9 were used to interpret ICC data (Koo & Li, 2016). In addition, Cohen's effect size was used to determine the size of treatment effects within groups (ES). The four cat - egories of ESs: are no significant (0.25), minor (0.25-0.50), moderate (0.50-1.0), and large (>1.0) (Cohen, 2013). The de - fined level of significance was p<0.05. Data were statistically analyzed using the IBM SPSS V.26 computing application (IBM Corp., Armonk, NY, USA). Results Thirty-nine individuals completed the study without men- tioning any harm they may have suffered as a result of the intervention training session. According to the Shapiro-Wilk test and Levene's test, all variables appeared to have a normal and homogenous distribution. Moreover, the ICC values for all three groups were higher than 0.9 between the pre-test and post-test for all parameters. Results of comparative analysis (one-way ANOVA) among ETG, STG, and CTG at baseline (see Table 3) revealed that there were no statistically signifi- cant differences before the start of the training program. Table 3. Baseline characteristics of participants in each training group Variables Group F P
three groups were higher than 0.9 between the pre-test and post-test for all parameters. Results of comparative analysis (one-way ANOVA) among ETG, STG, and CTG at baseline (see Table 3) revealed that there were no statistically signifi- cant differences before the start of the training program. Table 3. Baseline characteristics of participants in each training group Variables Group F P ETG (n=13) M±SD STG (n=13) M±SD CTG(n=13) M±SD Age (y) 16.54±0.52 16.62± 0.86 16.69±0.85 0.131 0.877 Height (m) 1.72±0.061 1.72±0.05 1.71±.04 0.153 0.859 Weight(kg) 57.76±2.29 56.42±2.00 56.96±2.24 1.249 0.299 1RMSquat (No) 53.00±1.78 53.00±1.78 54.00±1.78 1.368 0.267 1RMPush up (No) 23.77±1.96 23.31±2.097 23.85±1.77 0.290 0.750 Vo2max (ml.kg -1 .min -1 ) 68.38±1.23 68.40±1.19 68.37±1.089 0.002 0.998 5km time trial 1010.38±15.21 1010.02±14.90 1009.95±14.73 0.003 0.997 Note: M±SD=mean ± Standard deviation, ETG= Endurance Training group, STG= Strength training group, CTG= Concurrent training group, y= year, m= meter, kg= kilogram, ml.kg -1 .min -1 = milliliters per kilogram per minute, M= Male, F= Female, n= number of participants, No=number; P=statistical significance. As for the within-subject comparisons, the two-way re- peated ANOVA revealed (showed in Table 4), STG signifi- cantly improved between the pre-and post-tests in 1RM squat (p<0.001; d=8.40), 1RM push-up (p<0.001; d=7.26), VO2max (p=0.0185; d=0.19) and 5 km time trial (p=0.001; d=0.14). The effect size of these improvements was small in the case of VO2 max and 5-km time trial, and large for 1RM squats and push-ups. Similarly, ETG significantly improved between Table 4. Results were obtained by the Three Experimental Groups in the Pre-and Post-Test in all the Variables Assessed Variable Group PT (M± SD) POT(M±SD) P-valueCohen’s d 1RMSquat(Kg) STG 53.00±1.78 69.31±2.09 <0.001 8.40 ETG 53.00±1.78 59.23±1.96 <0.001 3.33 CTG 54.00±1.78 64.15±1.2 <0.001 6.69 Push Up (No) STG 23.31±2.09 38.38±2.06 <0.001 7.26 ETG 23.77±1.96 28.85±2.04 <0.001 2.32 CTG 23.85±1.77 34.00±1.78 <0.001 5.72 Vo2Max(mL/kg/min) STG 68.40±1.19 68.19±1.01 0.0185 0.19 ETG 68.38±1.24 71.24±0.78 <0.001 2.76 CTG 68.37±1.08 74.22±1.45 <0.001 4.58 5km Time Trial (sec) STG 1010.01±14.9 1012.66±13.4 0.011 0.14 ETG 1010.38±15.2 974.69±9.9 <0.001 2.78 CTG 1009.9±14.73 936.38±17.2 <0.001 4.53 Notes. 1RM: One-repetition maximum; CTG: Concurrent training group; ETG: Endurance Training group; M±SD: Mean ±
ETG 23.77±1.96 28.85±2.04 <0.001 2.32 CTG 23.85±1.77 34.00±1.78 <0.001 5.72 Vo2Max(mL/kg/min) STG 68.40±1.19 68.19±1.01 0.0185 0.19 ETG 68.38±1.24 71.24±0.78 <0.001 2.76 CTG 68.37±1.08 74.22±1.45 <0.001 4.58 5km Time Trial (sec) STG 1010.01±14.9 1012.66±13.4 0.011 0.14 ETG 1010.38±15.2 974.69±9.9 <0.001 2.78 CTG 1009.9±14.73 936.38±17.2 <0.001 4.53 Notes. 1RM: One-repetition maximum; CTG: Concurrent training group; ETG: Endurance Training group; M±SD: Mean ± Standard deviation; POT: Post-Test; PT: Pre-Test; STG: Strength training group
CONCURRENT STRENGTH AND ENDURANCE TRAINING | D. A. WONDEM & Z. M. TEGEGNE Sport Mont 21 (2023) 3 105 the pre-and post-tests in the following parameters:1RM squat (p<0.001; d=3.33), push-up (p<0.001; d=2.32), VO2 max (p<0.001; d=2.76) and 5-km time trial (p<0.001; d=2.78). The effect size of these improvements was large in the case of all variables. In addition, CTG significantly improved its results between the pre-and the post-tests in the following variables; 1RM squat (p<0.001; d=6.69), push-up (p<0.001; d=5.72), VO2 max (p<0.001; d=4.58) and 5-km time trial (p<0.001; d=4.53). The effect size of these improvements was large in the case of all variables. Then, the two-way repeated ANOVA (see Table 5) showed that there was a group-by-time interaction effect for 1RM squat, push-up, VO2 max, and 5-km time trial (F (2-36) =90.946, p<0.001, F (2-36) =543.257, p<0.001, F (2-36) = 138.841, p=0.001 and F (2-36) =175.685, p<0.001, respectively). The 1RM squat, 1RM push-up, VO2max, and 5-km time trial all showed a main effect of time (F (1-36) =1255.794, p<0.001, F (1-36) =6652.971, p<0.001, and F (1-36) =458.374, p<0.001, respectively). The 1RM squat (F (2-36) =36.508, p<0.001), push-up (F (2-36) =18.345, p<0.001), VO2 max (F (2-36) =26.579, p<0.001), and 5-km time trial (F (2-36) =26.155, p<0.001) were the last exercises to show a main impact of the group. Table 5. Between-Subjects Comparisons of all the Variables Assessed Variable Main Effect of Time Main Effect of Group Group x Time Interaction Effect F (1-36) P F (2-36) P F (2-36) P Body weight 385.714 <0.001* 1.635 0.209 428.464 <0.001* 1RMSquat 1255.79 <0.001* 36.508 <0.001* 90.946 <0.001* Push up 6652.97 <0.001* 18.345 <0.001* 543.257 <0.001* Vo2max 364.653 <0.001* 26.579 <0.001* 138.841 <0.001* 5km Time trial 458.374 <0.001* 26.155 <0.001* 175.685 <0.001* Notes. F: Variation between sample means/variation within the samples; p: Level of statistical significance; VO2max: Maximum oxygen consumption; *p<0.05 Table 6: Bonferroni post hoc comparison Group(I) Group(J) d= (I-J) CI 95 P-value (Up LB) 1RMSquat ST ETG 5.04* 3.55 6.53 0.000 CTG 2.08* 0.59 3.57 0.004 CTG ETG 2.96* 1.47 4.45 0.000 1RMPush up STG ETG 4.54* 2.65 6.43 0.000 CTG 1.92*
Description
This study investigates the effect of concurrent strength and endurance training on distance running performance.