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The aim of this study was to compare how respiratory compensation point (RCP) and end-test power (EP) change in response to the same four-week high intensity interval training (HIIT). The power output associated with RCP and EP before and after HIIT were recorded in 24 recreationally-active participants (14 men and 10 women). RCP was determined from an incremental exercise test and EP was derived from a three-minute maximal effort test on a cycle ergometer. A significant time (pretest/posttest) × measurement (EP/RCP) interaction was found (F(1, 23)=5.119, p<.05). Results from a paired-sample t-test indicated that both EP (t(23)= -5.221, p<.05) and RCP (t(23)=-3.049, p<.05) increased significantly from pretest to posttest. Furthermore, a small effect size (d=.36, 90%CI=[.13, .58]) was calculated for the pre/posttest changes in the examined thresholds indicating greater potential improvements in EP compared to RCP. The pre/posttest change in EP (mean=21 W, 90%CI=[14, 28 W]) exceeded its standard error of estimate (14 W), while RCP did not. Correlation analysis revealed that EP correlated with RCP at both pretest (r=.813, p<.05) and posttest (r=.873, p<.05), however, delta values between the two measures were not significantly related. Both EP and RCP can be used to assess the change of aerobic capacity after HIIT, but may be reflective of different physiological adaptations. Further, EP may be preferred over RCP when assessing the effects of HIIT.

The aim of this study was to examine the hormonal and strength responses to different periodization models of resistance training in male athletes. Eighteen experienced resistance trained males were randomly assigned to either a block (BP; n=10; age: 23.7±2.9 yr; body mass: 78.5±11.3 kg; height: 1.77±0.05 m) or weekly undulating (WUP; n=8; age: 26.0±5.7 y; body mass: 78.9±12.4 kg; height: 1.79±0.05 m) periodized resistance training program. Both programs consisted of four-training sessions per week for 15 weeks, and each was equated for training volume. Analysis of variance was used to compare strength performance and changes in hormone response between groups. Salivary samples were taken before and after the first and the last workout of each mesocycle of the training program and assessed for testosterone (T) and cortisol (C). Maximal strength testing occurred before and after the 15-week training program. A greater increase (p=.040) in bench press strength was observed in BP compared to WUP, while no between group differences were noted for lower body isometric strength (p=.168) and lean body mass (p=.344). Significant elevations in T were seen in both groups following the power training phase, while no differences were noted between BP and WUP during any other training cycle. Results indicated that BP stimulated greater gains in upper body strength compared to WUP. In addition, the power phase of training may provide a greater anabolic hormone response.

Increases in muscle size and strength are influenced by the mechanical and metabolic stresses imposed by resistance training. Mechanical stress is induced by the use of high-intensity training and it is believed it activates a larger percentage of muscle fibers. Conversely, metabolic stress is generated by high training volumes with moderate intensities using short rest intervals. This training paradigm results in greater fatigue and potentially stimulates a greater anabolic hormone response to exercise. Although evidence exists for both strategies, it still remains inconclusive whether one training paradigm is more advantageous than the other regarding muscle hypertrophy development. In untrained adults, the novelty of most resistance training programs may be sufficient to promote hypertrophy and strength gains, whereas greater training intensity may be more beneficial for trained adults. However, the body of well-designed research in this advanced population is limited. Therefore, the purpose of this brief review is to discuss the merits and limitations of the current evidence.

The purpose of this study was to investigate the effects of 30-second all out sprint interval exercise (SIE) vs. moderate aerobic exercise (MA) on excess post-exercise oxygen consumption (EPOC). Six recreationally-trained males (age=23.3±1.4 yrs, weight=81.8±9.9 kg, height=180.8±6.3cm) completed a sprint interval exercise session consisting of three repeated 30-second Wingate cycling tests separated by four minutes (duration~11minutes) as well as a moderate aerobic exercise session consisting of 30-minute cycling at 60% heart rate reserve (HRR) in a random counterbalanced design. Baseline oxygen consumption (VO2) was determined by an average VO2 from the final five minutes of a 30-minute supine rest period prior to each trial. Following each protocol, VO2 was measured for 30-minutes or until baseline measures were reached. EPOC was determined by subtracting baseline VO2 from post-exercise VO2 measurements. Energy expenditure (kJ) was determined by multiplying kJ per liter of oxygen by the average VO2 during recovery. EPOC values were significantly higher in SIE (7.5±1.3 L) than MA (1.8±0.7 L). SIE produced a higher recovery caloric expenditure (156.9 kJ) compared to MA (41.0 kJ) and remained significantly elevated (p=.024) over resting levels during the entire recovery period (30 minutes) compared to MA (6 minutes, p=.003). The energy required to recover from three repeated maximal effort 30-second Wingate cycling tests was greater than 30-minutes of moderate aerobic exercise. Future studies should examine the chronic effects of maximal effort sprint training protocol on cardiovascular fitness and body composition., Cilj je ovog istraživanja bio utvrditi učinke maksimalnog intervalnog sprintanja po 30 sekunda (SIE) i usporediti ih s umjerenim aerobnim treniranjem (MA) na povišenu potrošnju kisika nakon vježbanja. Šest muškaraca rekreativaca (23.3±1.4 godina, 81.8 ± 9.9 kg i 180.8 ± 6.3 cm) je, u slučajnom uravnoteženom nacrtu eksperimenta, provelo intervalni sprinterski trening koji se sastojao od tri ponavljanja Wingate testa (30 sekunda) na biciklu sa odmorima po 4 minute (ukupno trajanje zadatka približno 11 minuta) te umjereni aerobni trening koji se sastojao od 30 minuta bicikliranja intenzitetom od 60% rezerve srčane frekvencije. Početni primitak kisika (VO2) je bio utvrđen kao prosječna vrijednost VO2 zabilježena u zadnjih 5 minuta 30-minutnog odmora u ležećem položaju koji se primjenjivao prije svakog eksperimentalnog protokola. Nakon svakog protokola, VO2 je bio mjeren tijekom 30 minuta ili do trenutka kada se VO2 spustio na početnu vrijednost. EPOC je utvrđen oduzimanjem početne vrijednosti VO2 od vrijednosti VO2 zabilježenih nakon eksperimentalnih protokola. Energetska potrošnja (kJ) je bila utvrđena množenjem potrošenih kJ po litri kisika sa prosječnim VO2 tijekom oporavka. Vrijednosti EPOC-a bile su značajno više u sprinterskoj grupi (SIE 7,5±1,3 l) u odnosu na vrijednosti u grupi MA (1,8±0,7). Sprinterski zadatak je proizveo višu kalorijsku potrošnju tijekom oporavka (156,9 kJ) u usporedbi s umjerenim aerobnim zadatkom MA (41,0 kJ) te je ona ostala značajno povišena (p=0,024) u odnosu na razinu u mirovanju tijekom cijelog perioda oporavka (30 minuta) za razliku od MA (6 minuta, p=0,003). Potrebna energija za oporavak nakon 3 ponovljena maksimalna Wingate testa od 30 sekunda bila je viša nego nakon 30 minuta umjerene aerobne aktivnosti. Buduća istraživanja trebala bi ispitati kronične učinke protokola maksimalnih sprinterskih napora na kardiovaskularni fitnes i sastav tijela.