High-intensity interval training (HIIT) is considered an effective method to improve fitness and health indicators, but its high-intensity exercises and the mechanical and metabolic stress generated during the session can lead to the occurrence of exercise-induced muscle damage. Therefore, this study aimed to describe, by means of a systematic review, the effects of a single HIIT session on exercise-induced muscle damage. A total of 43 studies were found in the Medline/PubMed Science Direct/Embase/Scielo/CINAHL/LILACS databases; however, after applying the exclusion criteria, only 15 articles were considered eligible for this review. The total sample was 315 participants. Among them, 77.2% were men, 13.3% were women and 9.5 uninformed. Their age ranged from 20.1 ± 2 to 47.8 ± 7.5 years. HIIT protocols included running with ergometers (n = 6), CrossFit-specific exercises (n = 2), running without ergometers (n = 3), swimming (n = 1), the Wingate test on stationary bicycles (n = 2), and cycling (n = 1). The most applied intensity controls were %vVO₂max, “all out”, MV, MAV, Vmax, and HRreserve%. The most used markers to evaluate muscle damage were creatine kinase, myoglobin, and lactate dehydrogenase. The time for muscle damage assessment ranged from immediately post exercise to seven days. HIIT protocols were able to promote changes in markers of exercise-induced muscle damage, evidenced by increases in CK, Mb, LDH, AST, ALT, pain, and muscle circumference observed mainly immediately and 24 h after the HIIT session.

To describe external training load and internal training load through sets of a single session of high-intensity interval training (HIIT) body work.Twenty male individuals (24±3 years) performed a HIIT body work protocol consisting of a single ...

Introduction: Physical activity raises body temperature, increases the sweat rate and accelerates fluid loss during exercise, thereby impairing exercise performance. However, studies using the high intensity interval training (HIIT) approach and its effects on rates of perspiration and hydration are still inconclusive. Objectives: The objective of this study was to assess sweating and water loss during an HIIT workout session, using body weight, with healthy college students. Methods: Twenty male individuals (31 ± 07 years) were split into two groups: Active group (AG) and Inactive group (IG). The HIIT workout protocol, using body weight, consisted of a single bout with 1:1 stimuli, being: 30” “all out” intensity, involving jumping jack, mountain climber, burpee and squat jump exercises; and 30” of passive recovery, totaling 20 minutes of exercises. For comparison purposes, after 48 hours all the individuals underwent the continuous running protocol with intensity corresponding to 75% of maximum heart rate for 40 minutes. The intensity of the session was monitored continuously, at each 30”, using the perceived exertion scale for both protocols. To ensure euhydration status, all individuals ingested 500 ml of water 120 minutes before the training session. Results: Significant differences (p= 0.01) were found in body mass after HIIT compared to the Moderate session in both Active (HIIT: -0.60 ± 0.29 kg, Moderate: -0.26 ± 0.12 kg) and Inactive (HIIT: -0.92 ± 0.30 kg, Moderate: -0.26 ± 0.26 kg) groups, however, no differences were found between groups. Absolute sweating rate values comparing moderate and HIIT single bout in Inactive (Moderate: 10.55 ± 10.59 ml/min; HIIT: 28.90 ± 13.88 ml/min) and Active (Moderate: 9.60 ± 4.52 ml/min; HIIT: 26.00 ± 15.06 ml/min) groups were different between types of exercise, but not between groups. Conclusions: The sweating rate is influenced by the intensity of the exercise, being higher after HIIT than after a moderate exercise session. However, the sweating rate variation is not affected by the subjects’ physical activity level. Level of Evidence II; Diagnostic studies-Investigating a diagnostic test.

The aim of this study was to investigate the effectiveness of supervised and unsupervised physical training programs using outdoor gym equipment on the lifestyles of elderly people. Methods: physically independent elderly people were randomly distributed into three groups: supervised training (n: 20; ST), unsupervised training (n: 20; UT) and control (n: 20; C). The ST and UT groups completed a 12-week program, with exercises performed three times a week. The ST group underwent weekly 30 min sessions consisting of a 5 min warm-up (walking at 60% of HR_max), followed by 20 sets of 30, “monitored by a metronome with 30” of passive recovery between sets and a five-minute cool-down. The following equipment was used: elliptical, rowing, surfing and leg press. The UT group was instructed to freely attend the gym and train spontaneously using the same equipment used by ST. Lifestyle changes were evaluated using a questionnaire containing specific domains. Results: no significant differences were identified in the domains for family, physical activity, nutrition, smoking, sleep, behavior, introspection, work and overall score; however, the values corresponding to the alcohol domain for the ST and UT groups were lower (p < 0.05) than the C group, remaining even lower after the 12 weeks of intervention. Time effect (p < 0.05) was found only in the ST group for the physical domains, sleep, behavior and overall score. Conclusion: elderly people submitted to supervised and unsupervised physical exercise programs using outdoor gym equipment present positive changes in lifestyle parameters compared to physical inactive elderly people.

Our aim was to evaluate musculoskeletal discomfort and the lifestyle of military police officers of administrative and tactical force departments. Military police officers were distributed into two groups: administrative (Adm, n = 15) and tactical force (TF, n = 16) departments. Their lifestyle was assessed using the Fantastic Lifestyle questionnaire. Moreover, physical activity quantification was assessed using the International Physical Activity questionnaire, and musculoskeletal discomfort was quantified using the Corlett diagram. The mean total time of physical activity was 546 ± 276 min per week. No differences (p = 0.0832) were found between the Adm (454 ± 217 min) and TF (623 ± 301 min) groups. Concerning lifestyle, in general the sample presented very good (42%) and good (42%) style classification. For this parameter, no significant differences were found, but only a tendency was discovered (x²: 7.437; p = 0.0592); indeed, the TF presented a better classification (63%) of very good, compared to the Adm (53%) of good. No differences (p > 0.05) were found in musculoskeletal perception of discomfort between the right and left sides (p > 0.05) for all police officers and between the Adm and FT groups (p > 0.05). Military police officers showed high and moderate risk for waist circumference and waist-to-hip ratio, respectively; however, lifestyle and total time of physical activity were considered adequate without differences between military administrative and tactical force sectors.

The time-efficient nature of HIIT using bodyweight exercises can facilitate the application of exercise programs at home by encouraging more people to perform regular physical exercise. However, there are no studies investigating the influence of the distribution/order of exercises during HIIT training sessions using this method. The aim of the present study was to evaluate the effects of different exercise orders on training load indicators during HIIT sessions using body weight. Twenty male participants performed three 20-min sessions of HIIT using whole body exercise, consisting of 20 sets with 30 s of activity performed at maximal intensity, followed by 30 s of passive recovery. Three designs of exercise protocols were randomly performed according to the following exercise distribution: A: jumping jack, burpee, mountain climb and squat jump); B: jumping jack, mountain climb, burpee, and squat jump) and C: burpee, squat jump, jumping jack and mountain climb. No differences were found between protocols for relative heart rate, perceived exertion, and lactate concentrations. Significant differences (p < 0.001) were found for the number of movements (A:712 ± 59, B:524 ± 49, C:452 ± 65). No differences were observed for the area under curve when examining perceived exertion between protocols. However, the values for perceived recovery significantly differed (p < 0.001) between protocols (A:64 ± 19; B:52 ± 11; C:17 ± 13). Interestingly, protocol B and C induced a displeasure perception compared to protocol A. Our findings suggest that exercise distribution/order using HIIT whole body exercise promotes alterations in psychophysiological responses in HIIT using whole body exercises.