Abstract
aim of the study was to determine the effects of sprint interval training (SIT) on anaero- bic and aerobic performance in young physically active men, as assessed by maximal power (Pmax), maximal oxygen uptake (VO2max), and the second ventilatory threshold (VT2). The data obtained were presented against the background of the effects of aerobic interval train- ing. Participants (n= 45) aged 19–27 yearswere recruited into three groups of 15 participants each. The first group performed SIT, the second performed aerobic interval training (AIT), and the third group was without any intervention (control—CON). In each study group, par- ticipants performed somatic measurements twice (before and after the exercise intervention), the Wingate test (assessing peak anaerobic power (PP)), and a graded exercise test assessing aerobic performance. The training intervention in the SIT and AIT groups lasted 6 weeks, with three training sessions per week. The duration of a single session in AIT was constant throughout the intervention and lasted 60 min, while in SIT it lasted 17 min (first session), and the longest training session lasted 30 min. Training in the SIT group resulted in a significant increase inabsolute anaerobic peak power(p< 0.001, ES = 0.36),while no significant change in PP was observed after AIT(p= 0.13, ES = 0.24). Both trainingprotocols (SIT and AIT) sig- nificantly improved VO2max(p= 0.03, ES = 0.39 andp= 0.02, ES = 0.55, respectively) and absolute Pmax (p< 0.001, ES = 0.68 andp= 0.02, ES = 0.36). Only in the AIT group were statistically significant changes related to VT2 observed: after training, oxygen uptake at VT2 increased significantly(p= 0.04,
after AIT(p= 0.13, ES = 0.24). Both trainingprotocols (SIT and AIT) sig- nificantly improved VO2max(p= 0.03, ES = 0.39 andp= 0.02, ES = 0.55, respectively) and absolute Pmax (p< 0.001, ES = 0.68 andp= 0.02, ES = 0.36). Only in the AIT group were statistically significant changes related to VT2 observed: after training, oxygen uptake at VT2 increased significantly(p= 0.04, ES = 0.64). The SIT protocolimproved both aer- obic (VO2max) and anaerobic (PP) performance, but did not affect the VT2 level. The data indicate that SIT can be used for training in sports disciplines requiring aerobic and anaerobic performance. Keywords:training; muscle power; Wingate test; sprint; aerobic training; oxygen uptake 1. Introduction Sprint interval training (SIT) is defined as training with several tens of seconds of effort with long (several minutes) recovery breaks and is one of the forms of high-intensity interval training [1]. SIT is usually used to improve anaerobic performance (phosphagen and glycolytic) and to improve speed, muscle power, and acid–base balance tolerance [2,3]. SIT is based on anaerobic efforts performed with external resistance at maximal power and is a training method that induces physiological adaptations most likely resulting from increased activity of glycolytic, oxidative, and phosphagen enzymes [4,5]. Systematic SIT Appl. Sci.2026,16, 1373 https://doi.org/10.3390/app16031373
Appl. Sci.2026,16, 1373 2 of 17 training induces a number of biochemical changes. It has been proven that SIT training increases the activation of glycogen-metabolizing enzymes, glycolytic enzymes, oxidative enzymes, and creatine kinase or aminotransferase [4,5]. It also increases the release of calcium ions (Ca 2+ ) from the sarcoplasmic reticulum surrounding striated muscles [4]. The desired physiological effects of SIT include an increase in VO2max and peak anaerobic power (Pmax), as well as an improvement in the oxidative capacity of skeletal muscles [6–8]. After SIT training, an increase in resting muscle glycogen content of 26% was observed, as well as differences in muscle fiber changes to type IIa [9]. Although SIT is strictly anaerobic training of supramaximal intensity, its use in improv- ing aerobic performance is increasingly being considered [10,11], as metabolic adaptations to this training may also promote improvements in aerobic performance. Interval sprint training can therefore be an excellent substitute or supplement to endurance training. Previous studies [12–14] have shown that SIT not only increases peak anaerobic power (PP) and mean power (MP), but may also increase maximal oxygen uptake (VO2max) [11]. Similar conclusions were reached by other authors [12–15], proving the effectiveness of SIT in improving aerobic capacity in a similar way to low- or medium-intensity training of long duration. High-intensity interval training not only improves VO2max, but also leads to a reduction in body fat, and the changes observed were similar after both SIT and high-intensity interval training [11,16]. However, the data are not conclusive. Another study [17] showed that high-intensity training did not improve aerobic performance among professional judo practitioners. The results of the meta-analysis [18] indicate that long-term high-intensity interval training (power or velocity between the second ventilatory thresh- old and maximal oxygen consumption) may be the optimal form of interval training to augment aerobic performance. A moderate effect in favor of high-intensity interval training over SIT in maximal power (Pmax) or maximal aerobic velocity was detected. In order to assess aerobic performance, VO2max and the intensity of work at metabolic (ventilatory) thresholds (VT1 and VT2) are taken into account [19–21]. After exceeding
consumption) may be the optimal form of interval training to augment aerobic performance. A moderate effect in favor of high-intensity interval training over SIT in maximal power (Pmax) or maximal aerobic velocity was detected. In order to assess aerobic performance, VO2max and the intensity of work at metabolic (ventilatory) thresholds (VT1 and VT2) are taken into account [19–21]. After exceeding the first ventilatory threshold (VT1), metabolic acidosis occurs, causing an increase in lactate, which the body is able to compensate for [22]. Increasing exercise intensity causes the next metabolic threshold to be exceeded, which is the second ventilatory threshold (VT2),an important indicator in the assessment of aerobic endurance [23,24]. Exceeding VT2 causes hyperventilation and the development of uncompensated metabolic acidosis [25]. To improve aerobic capacity, training is usually performed at a submaximal continuous or intermittent intensity rather than supramaximal intensity, as in SIT. The study compared the effective- ness of two different training methods in improving physical performance—aerobic (AIT) and anaerobic (SIT)—i.e., methods that produce different physiological and biochemical effects. The biochemical benefits include increased oxidation of fatty acids and glucose [26], increased activity of enzymes involved in fatty acid oxidation (citrate synthesis, lactate de- hydrogenase, succinate dehydrogenase, phosphofructokinase) [27,28], and increased ATP production in mitochondria during physical exercise and the number of mitochondria in type Ia muscle fibers [29]. AIT increases the activity of oxidative enzymes (creatine kinase, myokinase, ATPase, phosphofructokinase, lactate dehydrogenase) [30–35] and increases erythrocyte production [36]. This type of training reduces systolic and diastolic blood pres- sure and improves myocardial function and vascular endothelial function [37]. Endurance training improves VO2max and shifts VT2 to higher exercise intensities, primarily through increased blood flow to skeletal muscle [38–40]. AIT training improves oxygen transport to cells and improves the functioning of the cardiorespiratory system [35,41]. AIT also reduces body fat [42] and causes bradycardia, thereby increasing heart rate reserve [43,44]. A typical, traditional AIT has submaximal intensity, usually not exceeding VT2, and is therefore not considered a high-intensity interval training [1]. https://doi.org/10.3390/app16031373
functioning of the cardiorespiratory system [35,41]. AIT also reduces body fat [42] and causes bradycardia, thereby increasing heart rate reserve [43,44]. A typical, traditional AIT has submaximal intensity, usually not exceeding VT2, and is therefore not considered a high-intensity interval training [1]. https://doi.org/10.3390/app16031373
Appl. Sci.2026,16, 1373 3 of 17 The aim of the study was to determine the comprehensive effects of sprint interval training on exercise capacity (anaerobic and aerobic capacity), and in particular on en- durance capacity among young untrained men, as assessed by maximal oxygen uptake and the second ventilatory threshold. For the aerobic metabolism, VO2max reflects maximal aer- obic power measured during maximal exercise. VT2 reflects aerobic capacity. In the same manner, for anaerobic glycolysis, also called “lactic anaerobic metabolism”, peak power (PP) reflects maximal anaerobic power, and mean power (MP) reflects anaerobic capacity in the Wingate Anaerobic Test. In this study, the data obtained were presented in contrast to the effects of aerobic interval training. We hypothesized that sprint interval training would be as effective in improving endurance capacity as traditional aerobic interval training and, unlike AIT, would be effective in improving anaerobic capacity. Thus, SIT may prove to be a more versatile training method, affecting both aerobic and anaerobic capacity. 2. Materials and Methods 2.1. Study Design The participants were physically active, but this activity was very varied, unsystematic, and varied in intensity and duration. For the duration of the intervention, they refrained from other physical activities they had previously been engaged in. They were not trained athletes and did not participate in any sports competitions. The study was experimental and designed as a parallel study. The study involved physically active men divided randomly into three groups. Randomization was performed using an online tool (www.randomizer.org, accessed on 6 March 2023). The first group performed SIT, the second group performed AIT. The last group did not undergo any training intervention (control group—CON). The sample size was determined before the study began. G*Power version 3.1.9.7 software (Germany) was used to calculate the sample size. The following data were entered into the software: test family = f tests; statistical test = ANOVA with repeated measures, within-between interaction; type of power analysis = calculation of the required sample size with assumedα, power, and effect size. The parameters entered into the software were as follows: effect size f: 0.25; error probabilityα: 0.05; power:
calculate the sample size. The following data were entered into the software: test family = f tests; statistical test = ANOVA with repeated measures, within-between interaction; type of power analysis = calculation of the required sample size with assumedα, power, and effect size. The parameters entered into the software were as follows: effect size f: 0.25; error probabilityα: 0.05; power: 0.80; number of groups: 3; number ofmeasurements: 2; correlation between measurements: 0.5; non-sphericity correction: 1.0. The required total sample size was42 participants. Due topossible dropouts from the study, we decided to recruit45 participants (15 per group).All participants completed the training sessions, and a complete set of data was obtained. Each person in the study group gave their written consent to participate in the study, and approval was obtained from the Bioethics Committee at the Regional Medical Chamber in Krakow, number: No. 187/KBL/OIL/2022 dated 1 July 2022. The exact course of the study is presented in Figure. The following inclusion criteria were used: male gender, age (19–27 years), sponta- neous irregular low-to-moderate physical activity, and no medical contraindications to participate in training. Exclusion criteria included obesity and overweight, chronic medical conditions, injuries and trauma within 6 months prior to the start of the project, and training in any sport. Accompanied by the researcher, participants completed a seven-day physical activity questionnaire. The exercise intervention in the SIT and AIT groups lasted six weeks with a frequency of three times per week. The group without intervention (CON) did not perform exercise training during this time. The study participants were introduced to the exercise test procedures and familiarized with the cycle ergometer technique (E834 Monark, Varberg, Sweden). The study participants were instructed on how to prepare for the exercise tests and training: they should be well rested, should not consume caffeine or alcohol for 24 h before the tests,should maintain their usual diet, and should not consume any dietary https://doi.org/10.3390/app16031373
Appl. Sci.2026,16, 1373 4 of 17 supplements during the intervention period. Before the training intervention, somatic measurements, a Wingate test, and a graded test took place, which were then repeated one week after the training. Measurements were taken on a single day. There was a 2 h gap between the Wingate test and the graded test. The exercise tests and workouts took place under similar conditions, with an ambient temperature of approximately 21 ◦ C and a humidity of approximately 40%. The workouts took place under the supervision of a sports/motor training instructor. Figure 1.The course of the study. 2.2. Somatic Measurements Each participant’s body composition was measured twice (before and after the training intervention), while body height (BH) was measured only once. Body composition was analyzed using a body composition analyzer (IOI 353, Jawon Medical, Seoul, Republic of Korea). The indices measured were: body mass index (BMI), body mass (BM), lean body mass (LBM), body fat percentage (%FM), and body fat mass (FM) expressed in kg. Body height was measured using a stadiometer (Seca 217, Hamburg, Germany) to the nearest 0.1 cm. 2.3. Graded Exercise Test (Ergospirometry) The graded exercise test, which is a direct method that determines maximal oxygen uptake under laboratory conditions, was conducted on a bicycle ergometer (Ergoline Er- goselect 100, GE, Bitz, Germany) using a Metalyzer 3B ergospirometer (Cortex, Leipzig, Germany). The following indices were measured in the test: power of effort (P), oxy- gen uptake (VO2), heart rate (HR), and respiratory exchange ratio (RER). To determine ventilatory thresholds, additional indicators were examined: pulmonary ventilation (VE), carbon dioxide production (VCO2), percentage of oxygen in exhaled air (FEO2), percentage of carbon dioxide in exhaled air (FECO2), ventilation equivalents for oxygen (VE/VO2), https://doi.org/10.3390/app16031373
Appl. Sci.2026,16, 1373 5 of 17 and carbon dioxide (VE/VCO2). Ventilatory thresholds were determined using the res- piratory equivalents method [45,46]. The criteria for the determination of the VT1 were as follows:—minimal level of FEO2and VE/VO2.The second ventilatory threshold was determined at the intensity at which VE/VCO2reached a minimum value, FECO2reached a maximum value, and a second breakdown of the linearity of pulmonary ventilation was observed. To determine VO2max, the following criteria were used: VO2did not increase with increasing power (plateau in VO2), RER > 1.1, and heart rate (HR) was close to HRmax (±5 bpm) [47]. If no plateau was observed, but the other criteria were met, VO2peak was taken as VO2max. During the first two minutes of the test, resting data were recorded, followed by a four-minute warm-up performed at a power of 60 W. Then, every 2 min, the power of the effort was increased by 30 watts until volitional fatigue. 2.4. Wingate Test In order to test anaerobic capacity, the Wingate test [48] was used. The following indices were determined in the test: peak power determined in absolute and relative values, mean power also expressed in absolute and relative values, and fatigue index (power loss) (FI). The test used a bicycle ergometer (E834, Monark, Sweden) and software (MCE, JBA Staniak, Warsaw, Poland). When entering the test, the participant had to have the saddle positioned, and then began the test, preceded by a 5 min warm-up with a load of 120 W and a cadence of 60 rpm. At the 2nd and 4th minute, the participant performed a maximum acceleration lasting 5–6 s. After completing the warm-up, the participant rested for 5 min (including 4 min of stretching the lower extremities). The test had a stationary start [49], and the participant’s task was to reach maximum pedaling speed (revolutions per minute) as fast as possible and then maintain it until the end of the test (all-out effort). The Wingate test consisted of a 30 s sprint with a load of 7.5% of body mass. The effort took place in a seated position, and during the Wingate test,
[49], and the participant’s task was to reach maximum pedaling speed (revolutions per minute) as fast as possible and then maintain it until the end of the test (all-out effort). The Wingate test consisted of a 30 s sprint with a load of 7.5% of body mass. The effort took place in a seated position, and during the Wingate test, the participant was verbally motivated to achieve the highest possible pedaling speed. 2.5. Physical Activity Prior to the study, participants completed the Physical Activity Recall (PAR) question- naire, which was used to determine seven days of physical activity [50,51]. Each participant was instructed on how to complete the questionnaire, and it was completed in the presence of the researcher, who clarified any doubts the participant may have had. 2.6. Aerobic Interval Training Aerobic interval training (AIT) was performed on cycle ergometers (Wattbike, Nottingham, UK). Exercise intensity was determined by power noted at the first and second ventilatory thresholds (VT1 and VT2) (Table the participant performed a 6 min warm-up with power at VT1, then the participant performed a 6 min effort with power at VT2. Between efforts there was an active recovery of 3 min with power at VT1 (the exercise/recovery ratio was therefore 2:1). During the training session, which lasted 60 min, the participant performed six such series, i.e., 6 min of effort with power corresponding to VT2 and 3 min of active recovery with power corresponding to VT1. Table 1.Characteristics of training loads in the AIT group. Variable Mean ±SD VT1_P (W) 70.8 ±17.6 VT1_%Pmax 24.9±5.9 https://doi.org/10.3390/app16031373
Appl. Sci.2026,16, 1373 6 of 17 Table 1.Cont. Variable Mean ±SD VT1_%HRmax 63.3±5.1 VT1_%VO2max 34.7±4.9 VT2_P (W) 162 ±21.1 VT2_%Pmax 57.4±8.6 VT2_%HRmax 80.5±6.0 VT2_%VO2max 61.2±9.8 Pmax: maximal power; VO2max: maximal oxygen uptake; HRmax: maximal heart rate; VT1: first ventilatory threshold; VT2: second ventilatory threshold. 2.7. Sprint Interval Training The SIT was performed on a cycle ergometer (Monark 834, Sweden). Each workout consisted of a warm-up modeled on the Wingate test protocol. Immediately following the warm-up, the men performed 15 s sprint efforts of supramaximal intensity (all-out) with a load of 7.5% of body mass, i.e., a 15 s shortened version of the Wingate test. The participants were instructed to exert the same effort as during the Wingate test, i.e., their task was to sprint at maximum pedaling cadence in each effort. Neither power nor pedaling cadence was controlled during these efforts. For the first 2 weeks, participants performed three such supramaximal efforts and then increased the number of repetitions by one effort per training session per week. Thus, in the third week of training, there were 4 supramaximal efforts per training session, in the fourth week—5 efforts, in the fifth week—6 efforts, and in the last week of training, the number of efforts was reduced to 4. The shortest training session lasted 17 min, and the longest lasted 30 min. Between efforts there was a 4 min active rest, during which participants pedaled at 60 watts (Table). Table 2.Training plan implemented by the sprint interval training group.Week Training Intensity Volume (Series×Time Duration) I I all out 3 ×15 s II all out 3 ×15 s III all out 3 ×15 s II IV all out 3 ×15 s V all out 3 ×15 s VI all out 3 ×15 s III VII all out 4 ×15 s VIII all out 4 ×15 s IX all out 4 ×15 s IV X all out 5 ×15 s XI all out 5 ×15 s XII all out 5 ×15 s V XIII all out 6 ×15 s XIV all out 6 ×15 s XV all out 6 ×15 s VI XVI all
III VII all out 4 ×15 s VIII all out 4 ×15 s IX all out 4 ×15 s IV X all out 5 ×15 s XI all out 5 ×15 s XII all out 5 ×15 s V XIII all out 6 ×15 s XIV all out 6 ×15 s XV all out 6 ×15 s VI XVI all out 4 ×15 s XVII all out 4 ×15 s XVIII all out 4 ×15 s https://doi.org/10.3390/app16031373
Description
This study compares the effects of sprint and aerobic interval training on performance metrics.