Performance and physiological effects of different descending strategies for cross-country mountain biking

This study investigated the performance-related feasibility and physiological benefits of purposefully eliminating propulsive work while descending in mountain biking and compared values to those measured during road descending. Participants cycled uphill on a road at race pace before descending over three conditions (off-road pedalling; off-road coasting; road coasting). Relatively low power output during off-road pedalling was associated with a greater oxygen uptake (p?<?.01) when compared with off-road coasting despite no difference in vibration exposure (p?>?.05). Importantly, pedalling did not invoke a performance benefit (p?>?.05) on the descent used in this study. Significantly greater heart rate and oxygen uptake (both p?<?.01) were observed between road and off-road descending, likely caused by the increase in terrain-induced vibrations (p?<?.01) experienced between the bicycle and rider. Results indicate that reducing propulsive work during descending can improve recovery without being disadvantageous to performance. Similarly, the vibrations experienced during road descending are relatively low, and further reduce oxygen cost. In an effort to increase efficiency, it is recommended that mountain bike athletes focus on skills to increase descending speed without the addition of pedalling, and that equipment be used to decrease vibrations nearer to those seen on the road.     

The influence of shoe drop on the kinematics and kinetics of children tennis players

This study investigated the immediate effects of reducing the shoe drop (i.e. the difference between the heel and the forefoot height) on the kinematics and kinetics of the lower extremities of children tennis players performing a tennis-specific movement. Thirteen children tennis players performed a series of simulated open stance forehands wearing 3 pairs of shoes differing only in the drop: 0 (D0), 6 (D6) and the control condition of 12?mm (D12). Two embedded forceplates and a motion capture system were used to analyse the ground reaction forces and ankle and knee joint angles and moments of the leading lower limb. In D6 compared with D12, the peak impact force was reduced by 24% (p?=?.004) and the ankle was less dorsiflexed at foot strike (p?=?.037). In D0 compared with D12, the peak impact force was reduced by 17% (p?=?.049), the ankle was less dorsiflexed at foot strike (p?=?.045) and the knee was more flexed at foot strike (p?=?.007). In addition, 4 out of 13 participants (31%) presented a forefoot strike pattern for some of the trials in D0. No difference was observed across shoe conditions for the peak knee extensor moment (p?=?.658) or the peak ankle plantarflexor moment (p?=?.071). The results provide preliminary data supporting the hypothesis that for children tennis players, using a 6-mm lower shoe drop might reduce heel impact forces and thus limit potentially impact-related injuries.     

Effects of strength,explosive and plyometric training on energy cost of running in ultra-endurance athletes

The aim of the present study was to evaluate the effects of a 12-week home-based strength, explosive and plyometric (SEP) training on the cost of running (Cr) in well-trained ultra-marathoners and to assess the main mechanical parameters affecting changes in Cr. Twenty-five male runners (38.2?±?7.1 years; body mass index: 23.0?±?1.1?kg·m^?2; V˙O₂max: 55.4?±?4.0 mlO₂·kg^?1·min^?1) were divided into an exercise (EG?=?13) and control group (CG?=?12). Before and after a 12-week SEP training, Cr, spring-mass model parameters at four speeds (8, 10, 12, 14?km·h^?1) were calculated and maximal muscle power (MMP) of the lower limbs was measured. In EG, Cr decreased significantly (p?<?.05) at all tested running speeds (?6.4?±?6.5% at 8?km·h^?1; ?3.5?±?5.3% at 10?km·h^?1; ?4.0?±?5.5% at 12?km·h^?1; ?3.2?±?4.5% at 14?km·h^?1), contact time (t_c) increased at 8, 10 and 12?km·h^?1 by mean +4.4?±?0.1% and t_a decreased by ?25.6?±?0.1% at 8?km·h^?1 (p?<?.05). Further, inverse relationships between changes in Cr and MMP at 10 (p?=?.013; r?=??0.67) and 12?km·h^?1 (p?<?.001; r?=??0.86) were shown. Conversely, no differences were detected in the CG in any of the studied parameters. Thus, 12-week SEP training programme lower the Cr in well-trained ultra-marathoners at submaximal speeds. Increased t_c and an inverse relationship between changes in Cr and changes in MMP could be in part explain the decreased Cr. Thus, adding at least three sessions per week of SEP exercises in the normal endurance-training programme may decrease the Cr.     

A shower before bedtime may improve the sleep onset latency of youth soccer players

During the competitive season, soccer players are likely exposed to numerous factors that may disrupt the process of sleep. The current investigation looked to evaluate a practical sleep hygiene strategy (10-min showering at ～40°C before lights out), within a group of 11 youth soccer players in comparison to normal sleeping conditions (control). Each condition consisted of three days within a randomised crossover trial design. Sleep information was collected using a commercial wireless bedside sleep monitor. Measures of skin temperature were evaluated using iButton skin thermistors to establish both distal and proximal skin temperatures and distal to proximal gradient. The shower intervention elevated distal skin temperature by 1.1°C (95% CI: 0.1–2.1°C, p?=?.04) on average prior to lights out. The elevation in distal temperature was also present during the first 30-min following lights out (1.0°C, 95% CI: 0.4–1.6°C, p?<?.01). The distal to proximal gradient also showed a significant effect between the conditions within the first 30-min after lights out (0.7°C, 95% CI: 0.3–1.2°C, p?<?.01). On average the sleep latency of the youth soccer players was ?7-min lower (95% CI: ?13 to ?2?min, p?<?.01) and sleep efficiency +2% higher (95% CI: 1–3%; p?<?.01) in the shower condition. These findings demonstrate that a warm shower performed before lights out may offer a practical strategy to promote thermoregulatory changes that may advance sleep onset latency and improve sleep efficiency in athletes.     

Effects of competition on the sleep patterns of elite rugby union players

Abstract

No published research has assessed sleep patterns of elite rugby union players following match-play. The present study examined sleep patterns of professional rugby union players, prior and post-match-play, to assess the influence of competition. Twenty-eight male rugby union players (24.4?±?2.9 years, 103.9?±?12.2?kg) competed in one of four competitive home matches. Player's sleep behaviours were monitored continuously using an Actiwatch^® from two days before the match, until three days post-match. Repeated measures of analysis of variance (ANOVA) showed significant differences across the time points measured for time to bed (F?=?26.425, η² ?=?0.495, p < .001), get up time (F?=?21.175, η²?=?0.440, p?<?.001), time spent in bed (F?=?10.669, η²?=?0.283, p?<?.001), time asleep (F?=?8.752, η²?=?0.245, p?<?.001) and percentage of time moving (F?=?4.602, η²?=?0.146 p?<?.05). Most notable, post hocs revealed a significant increase for time in bed the night before the match (p?<?.01; 95% CI?=?0?:?10–1?:?28?h; 9.7?±?13.5%) compared with the reference night sleep. Furthermore, time asleep significantly decreased post-match (p?<?.05; 95% CI?=??0:03 to ?1:59?h; ?19.5?±?19.8%) compared to two nights pre-match. Across all time points, sleep latency and efficiency for most players were considered abnormal compared to that expected in normal populations. The results demonstrate that sleep that is deprived post-match may have detrimental effects on the recovery process.     

Impact of a physical education-based behavioural skill training program on cognitive antecedents and exercise and sport behaviour among adolescents: a cluster-randomized controlled trial

ABSTRACT

Background: School-based physical education has been associated with a multitude of potential learning outcomes. Representatives of a public health perspective suggest that promoting physical activity in and outside the context of school is an important endeavour. While the importance of behavioural skill training to improve (motor) learning is well documented in both general and physical education, the promotion of behavioural skills to foster physically active lifestyles constitutes a rather neglected area in physical education research.

Purpose: To examine whether a standardized physical education-based behavioural skill training program has the potential to positively impact on adolescents’ self-reported exercise and sport participation, as well as cognitive antecedents involved in the regulation of exercise and sport behaviour.

Research design: Cluster-randomized controlled trial.

Methods: A sample of 143 secondary school students (50% girls, aged 14–18 years) attending academic high schools in German-speaking Switzerland were assigned class-wise to the intervention (behavioural skill training) and control condition (conventional physical education lessons). Data were assessed prior and after completion of the 7-week intervention program, which was composed of four 20-min lessons and two reflection phases. Exercise and sport behaviour and cognitive antecedents (exercise/sport intention, motivation, implementation intentions, coping planning, self-efficacy) were assessed via self-reports. A multilevel mixed effects linear regression procedure was used to test the main hypotheses. The regression analyses were adjusted for clustering of school classes, and controlled for baseline levels of the outcome measure and potential confounders.

Results: Compared to a control condition, the intervention program resulted in significant improvements with regard to introjected motivation (p?<?.05), coping planning (p?<?.001) and self-efficacy (p?<?.01). The intervention also had a positive impact on adolescents’ self-reported sport/exercise behaviour (p?<?.001). Improvements in exercise/sport intention (p?<?.05), coping planning (p?<?.01), and self-efficacy (p?<?.01) were associated with increased levels of self-reported exercise/sport participation.

Conclusion: Behavioural skill training as part of compulsory physical education has the potential to improve cognitive antecedents of exercise and sport behaviour and to foster adolescents’ exercise and sport participation. Enhancing behavioural skills might be one way in which school physical education can contribute to the creation of more physically active lifestyles among adolescents.     

Is salivary cortisol moderating the relationship between salivary testosterone and hand-grip strength in healthy men?

This study examined the moderating effect of cortisol (C) on the relationship between testosterone (T) and hand-grip strength (HGS) in healthy young men. Sixty-five males were monitored for salivary T, C and HGS before and 15?min after a short bout (5?×?6-s trials) of sprint cycling exercise. Sprint exercise promoted (p?<?.05) positive changes in T (6.1?±?24.9%) and HGS (3.4?±?7.5%), but a negative C response (?14.4?±?33.1%). The T and C measures did not independently predict HGS, but a significant T?×?C interaction was found in relation to these outcomes. Further testing revealed that pre-test T and HGS were negatively associated (p?<?.05), but only in men with high C levels. The exercise changes in T and HGS were also negatively related in men with low C levels (p?<?.05), but no relationship was seen in men with high C levels. In summary, complex relationships between T and HGS emerged when considering C as a moderating variable. The pre-test combination of high C and low T levels favoured absolute HGS, whereas low pre-test C levels and a smaller T change were linked to larger HGS changes. These associations suggest that, in the current format, T is not necessarily anabolic to muscle strength in healthy young men. Such complexities could also explain some of the inconsistent T relationships with physical performance in lesser trained male populations.     

Impact of carbohydrate mouth rinsing on time to exhaustion during Ramadan: A randomized controlled trial in Jordanian men

Mouth rinsing using a carbohydrate (CHO) solution has been suggested to improve physical performance in fasting participants. This study examined the effects of CHO mouth rinsing during Ramadan fasting on running time to exhaustion and on peak treadmill speed (V_peak). In a counterbalanced crossover design, 18 sub-elite male runners (Age: 21?±?2 years, Weight: 68.1?±?5.7?kg, VO_2max: 55.4?±?4.8?ml/kg/min) who observed Ramadan completed a familiarization trial and three experimental trials. The three trials included rinsing and expectorating a 25?mL bolus of either a 7.5% sucrose solution (CHO), a flavour and taste matched placebo solution (PLA) for 10?s, or no rinse (CON). The treatments were performed prior to an incremental treadmill test to exhaustion. Three-day dietary and exercise records were obtained on two occasions and analysed. Anthropometric characteristics were obtained and recorded for all participants. A main effect for mouth rinse on peak velocity (V_peak) (CHO: 17.6?±?1.5?km/h; PLA: 17.1?±?1.4?km/h; CON: 16.7?±?1.2?km/h; P?η_p²?=?0.49) and time to exhaustion (CHO: 1282.0?±?121.3?s; PLA: 1258.1?±?113.4?s; CON: 1228.7?±?98.5?s; P?=?.002, η_p²?=?0.41) was detected, with CHO significantly higher than PLA (P?P?P?>?.05). Energy availability from dietary analysis, body weight, and fat-free mass did not change during the last two weeks of Ramadan (P?>?.05). This study concludes that carbohydrate mouth rinsing improves running time to exhaustion and peak treadmill speed under Ramadan fasting conditions.     

Kinematic and kinetic differences in block and split-stance standing starts during 30 m sprint-running

Abstract

This study aimed to understand the kinematic and kinetic differences between two sprint starts: block and split-stance standing. Fourteen sub-elite male sprinters (100 m time: 11.40?±?0.39?s) performed block and split-stance standing starts sprints over 30 m of in-ground force platforms in a randomised order. Independent t-tests and repeated measures mixed model analysis of variance were used to analyse the between-condition variables across conditions, and over four step phases. Block start sprints resulted in significantly (p?<?.05) faster 5 m (5.0%, effect size [ES]?=?0.89) and 10?m (3.5%, ES?=?0.82) times, but no significant differences were found at 20 and 30?m. No significant differences were found in any kinematic measure between starting positions. However, block starts resulted in significantly (p?<?.001) greater propulsive impulses (6.8%, ES?=?1.35) and net anterior-posterior impulses (6.5%, ES?=?1.12) during steps 1–4, compared to the standing start. Block starts enable athletes to produce a greater amount of net anterior-posterior impulse during early accelerated sprinting, resulting in faster times up to 10 m. When seeking to improve initial acceleration performance, practitioners may wish to train athletes from a block start to improve horizontal force production.     

Effects of strength and endurance exercise order on endocrine responses to concurrent training

The present study examined the effect of strength and endurance training order on the endocrine milieu associated with strength development and performance during concurrent training. A randomised, between-groups design was employed with 30 recreationally resistance-trained males completing one of four acute experimental training protocols; strength training (ST), strength followed by endurance training (ST-END), endurance followed by strength training (END-ST) or no training (CON). Blood samples were taken before each respective exercise protocol, immediately upon cessation of exercise, and 1?h post cessation of exercise. Blood samples were subsequently analysed for total testosterone, cortisol and lactate concentrations. Ability to maintain 80% 1RM during strength training was better in ST and ST-END than END-ST (both p?<?.05). Immediately following the respective exercise protocols all training interventions elicited significant increases in testosterone (p?<?.05). ST and END-ST resulted in greater increases in cortisol than ST-END (both p?<?.05). The testosterone:cortisol ratio was similar following the respective exercise protocols. Blood lactate concentrations post-training were greater following END-ST and ST than ST-END (both p?<?.05). Conducting endurance exercise prior to strength training resulted in impaired strength training performance. Blood cortisol and lactate concentrations were greater when endurance training was conducted prior to strength training than vice versa. As such, it may be suggested that conducting endurance prior to strength training may result in acute unfavourable responses to strength training when strength training is conducted with high loads.     

Effects of a phase change cooling garment during exercise in the heat

The purpose of our study was to examine the physiological, perceptual, and performance effects of wearing a phase change cooling garment (CG) during an interval exercise routine in the heat. Sixteen male participants (age 23?±?3 years, ht 1.76?±?0.11?m; wt 78.5?±?11.2?kg; body fat 15.2?±?5.8%) completed two trials (one with phase change inserts, CG, and one control without inserts) consisting of two submaximal exercise portions separated by 5-minute seated rest, and a final maximal effort performance bout. Each submaximal bout involved 30?seconds or 1?minute of muscular endurance and agility exercises and 5?minutes of treadmill jogging and step-ups. The performance bout included 30?seconds or 1?minute of muscular endurance and agility exercises, with participants completing as many repetitions as possible, followed by a 15-minute recovery (active and passive). Rectal temperature (T_re) and heart rate were not different between trials, however change in T_re from baseline was improved during 10 and 15 minutes of recovery with the CG (P?<?.05). Mean skin temperature was lower using the CG vs control throughout the trial (P?<?.05). Thermal sensation was lower when using the CG compared to control (P?<?.001). There were no differences in any outcomes of the performance exercises (P?>?.05). These findings indicate that the continuous use of a CG during an interval style workout in the heat provides improvements in thermal sensation, however, only minimal thermophysiological benefits, and no performance augmentation.     

Assessment of subcutaneous adipose tissue using ultrasound in highly trained junior rowers

Introduction: There is a large variety of body fat (BF) measurements, which differ in validity and reliability. The aim of this study was to measure subcutaneous adipose tissue (SAT) using ultrasound (US) in highly trained junior rowers in a field setting, establish fat patterning profiles, and compare the profiles between male and female athletes. Skinfold thickness (SKF) measurements were also taken and compared to US measurements. Methods: Sixteen athletes participated. US measurements were taken at eight sites and reported as a sum of SAT (D): D_Excl (without embedded structures) and D_Incl (including embedded structures). SKF was measured at three sites and reported as a sum of adipose tissue thickness (SUM_SKF). Results: Mean SAT thickness (D_Incl) was 27.6?±?12.4?mm for males and 65.5?±?11.8?mm for females. Females had significantly more embedded structures than males (P?=?.016). Significant correlations were found (P?<?.001, r?=?0.92) comparing SUM_SKF to D_Incl and between SKF and US measurements at the thigh site (P?<?.001, r?=?0.86). Conclusion: US is a suitable tool to measure BF in the field testing of athletes and enables measurements of SAT with an accuracy and reliability not reached before. The sum of thicknesses (D_Incl or D_Excl) can be used to represent subcutaneous fat based on accurate measurements of uncompressed SAT thicknesses.     

Effect of shoe wearing time and midsole hardness on ground reaction forces,ankle stability and perceived comfort in basketball landing

ABSTRACT

This study examined the effect of wearing time on comfort perception and landing biomechanics of basketball shoes with different midsole hardness. Fifteen basketball players performed drop landing and layup first step while wearing shoes of different wearing time (new, 2-, 4-, 6- and 8-week) and hardness (soft, medium and hard). Two-way ANOVA with repeated measures was performed on GRF, ankle kinematic and comfort perception variables. Increased wearing time was associated with poorer force attenuation and comfort perception during landing activities (p < 0.05). The new shoes had significantly smaller forefoot (2- and 4-week) and rearfoot peak GRF impacts (all time conditions) in drop landing and smaller rearfoot peak GRF impact (6- and 8-week) in layup; shoes with 4-week of wearing time had significantly better perceptions of forefoot cushioning, forefoot stability, rearfoot cushioning, rearfoot stability and overall comfort than the new shoes (p < 0.05). Compared with hard shoes, the soft shoes had better rearfoot cushioning but poorer forefoot cushioning (p < 0.05). Shoe hardness and wearing time would play an influential role in GRF and comfort perception, but not in ankle kinematics. Although shoe cushioning performance would decrease even after a short wearing period, the best comfort perception was found at 4-week wearing time.     

Effects of high-intensity resistance circuit-based training in hypoxia on body composition and strength performance

Abstract

Hypoxic training methods are increasingly being used by researchers in an attempt to improve performance in normoxic ambients. Moreover, previous research suggests that resistance training in hypoxia can cause physiological and muscle adaptations. The primary aim of this study was to compare the effects of 8 weeks of high-intensity resistance circuit-based (HRC) training in hypoxia on body composition and strength performance. The secondary aim was to examine the effects of HRC on metabolic parameters. Twenty-eight male participants were randomly assigned to either hypoxia (Fraction of inspired oxygen [F_IO₂]?=?15%; HRC_hyp: n?=?15; age: 24.6?±?6.8 years; height: 177.4?±?5.9?cm; weight: 74.9?±?11.5?kg) or normoxia [F_IO₂]?=?20.9%; HRC_norm: n?=?13; age: 23.2?±?5.2 years; height: 173.4?±?6.2?cm; weight: 69.4?±?7.4?kg) groups. Training sessions consisted of two blocks of three exercises (Block 1: bench press, leg extension and front pull down; Block 2: deadlift, elbow flexion and ankle extension). Each exercise was performed at six repetition maximum. Rest periods lasted for 35-s between exercises, 3-min between sets and 5-min between blocks. Participants exercised twice weekly for 8 weeks, and body composition, strength and blood tests were performed before and after the training program. Lean body mass and bone mineral density significantly increased over time in the HRC_hyp (p?<?.005; ES?=?0.14 and p?<?.014; ES?=?0.19, respectively) but not in the HRC_norm after training. Both groups improved their strength performance over time (p?<?.001), but without group effect differences. These results indicate that simulated hypoxia during HRC exercise produced trivial effects on lean body mass and bone mineral density compared to normoxia.     

Could Slackline Training Complement the FIFA 11+ Programme Regarding Training of Neuromuscular Control?

The current study compared changes in neuromuscular control between slackline training and the stabilization training elements of the FIFA 11+ programme. Twenty-five students in 2 groups performed a 12-unit training programme. The slackline training group (n?=?13) exclusively trained with a slackline. The stabilization training group (n?=?12) practised exercises as described in the second part of the FIFA 11+ programme. Improvements in balance were assessed using three tests for dynamic, quasi-static, and perturbed postural control: the star excursion balance test (SEBT), the closed-eye single-leg stance, and the MFT S3-Check. Both groups significantly improved the stability and sensorimotor index of the MFT S3-Check (p?<?.001), their range on the SEBT (p?<?.001), and the duration of closed-eye single-leg stance (p?<?.001). The group?×?training interaction was significant for the MFT S3-Check (stability index: p?=?.042; sensorimotor index: p?=?.004) and the SEBT (dominant leg: p?=?.003; averaged both legs: p?=?.016), with the slackline training group showing a larger training effect than the stabilization training group. The results of the present study suggest that slackline training offers similar – or better – improvements in neuromuscular control as the FIFA 11+ warm-up programme. If compliance with the FIFA 11+ programme is declining, then slacklining might offer an alternative approach to reach the training goals of improved sensorimotor control.     

Evidence of sub-optimal sleep in adolescent Middle Eastern academy soccer players which is exacerbated by sleep intermission proximal to dawn†

The purpose was to assess sleep patterns, quantity and quality in adolescent (16.2?±?1.2 yr) Middle Eastern academy soccer players (n?=?20) and the influence of an intermission upon these characteristics. On a 17-day training camp (located one time zone west of home) including three discrete matches, sleep was assessed pre- (PRE) and post-match (POST) via wrist actigraphy. Retrospective actigraphy analysis identified sleep characteristics, including if players experienced a sleep intermission (YES) or not (NO) proximal to dawn, and bedtime (hh:mm), get-up time (hh:mm), time in bed (h), sleep duration (h) and sleep efficiency (%). Within YES two bouts were identified (BOUT1 and BOUT2). No differences were seen between PRE and POST, nor between BOUT1 and BOUT2 (p?>?.05). Overall players did not meet National Sleep Foundation (NSF) guidelines (7:04?±?1:16?h vs. recommended 8–10?h for 14–17 yr). Sleep duration was significantly reduced (～ ?13% or ?1:06) in YES compared to NO (6:33?±?1:05 vs. 7:29?±?1:17, p?<?.01). Despite players in YES waking earlier due to an intermission, they did not compensate for this with a later wake time, rising significantly earlier compared to NO (09:40?±?00:38 vs. 10:13?±?00:40, p?<?.05). These players on average do not obtain sufficient sleep durations relative to NSF guidelines, with decrements increased by an intermission proximal to dawn. High inter- and intra-individual variance in the players sleep characteristics indicates the need for individualized sleep education strategies and interventions to promote appropriate sleep.     

The effect of sex and localised fatigue on triceps surae musculoarticular stiffness

Purpose: The main purpose of this study was to investigate the influence of fatigue on musculoarticular stiffness (MAS) of the ankle joint across sexes. Methods: Twenty-seven males and 26 females participated in the study. After baseline assessment of MAS and related variables, localised fatigue was induced in triceps surae using the standing heel-rise test during which the subjects were instructed to lift and drop the heel at a frequency of 0.5?Hz. When subjects were unable to continue due to exhaustion the test was terminated and another MAS test was performed soon after. Results: Significant higher triceps surae MAS was found in men compared to women (p?p??1 and from 14.5 to 13.9?KN?m^?1 in men and women, respectively. Percentage changes revealed, however, that in relative terms the changes in all the variables evaluated were similar (p?>?.01) between sexes, with MAS less than 5%. Conclusion: Despite the sex-related differences at baseline, fatigue seems to affect biomechanical properties of the ankle joint similarly in men and women.     

High-intensity interval and moderate-intensity continuous training elicit similar enjoyment and adherence levels in overweight and obese adults

Background: High-intensity interval training (HIIT) has been shown to improve cardiometabolic health during supervised lab-based studies but adherence, enjoyment, and health benefits of HIIT performed independently are yet to be understood. We compared adherence, enjoyment, and cardiometabolic outcomes after 8 weeks of HIIT or moderate-intensity continuous training (MICT), matched for energy expenditure, in overweight and obese young adults. Methods: 17 adults were randomized to HIIT or MICT. After completing 12 sessions of supervised training over 3 weeks, participants were asked to independently perform HIIT or MICT for 30 min, 4 times/week for 5 weeks. Cardiometabolic outcomes included cardiorespiratory fitness (VO₂ peak), lipids, and inflammatory markers. Exercise enjoyment was measured by the validated Physical Activity Enjoyment Scale. Results: Exercise adherence (93.4?±?3.1% vs. 93.1?±?3.7%, respectively) and mean enjoyment across the intervention (100.1?±?4.3 vs. 100.3?±?4.4, respectively) were high, with no differences between HIIT and MICT (p?>?.05). Similarly, enjoyment levels did not change over time in either group (p?>?.05). After training, HIIT exhibited a greater decrease in low-density lipoprotein cholesterol than MICT (?0.66?mmol?L^?1 vs. ?0.03?mmol?L^?1, respectively) and a greater increase in VO₂ peak than MICT (p?<?.05, +2.6?mL?kg?min^?1 vs. +0.4?mL?kg?min^?1, respectively). Interleukin-6 and C-reactive protein increased in HIIT (+0.5?pg?mL^?1 and +?31.4?nmol?L^?1, respectively) and decreased in MICT (?0.6?pg?mL^?1 and ?6.7?nmol?L^?1, respectively, p?<?.05). Conclusions: Our novel findings suggest that HIIT is enjoyable and has high unsupervised adherence rates in overweight and obese adults. However, HIIT may be associated with an increase in inflammation with short-term exercise in this population.