Influence Of Combining Aerobic And High Intensity Interval Training οN 400m Performance And Post-exercise Responses.

Abstract

PURPOSE: To examine the possible influence of combining aerobic and high intensity interval training (HIIT) on post-exercise responses in 400m in young sprinters. METHODS: Fourteen male sprinters (100-200 m) (18.4 ± 0.3 years old; mean ± SE) performed 400m at maximal effort (400mMax), 400m at 90% (400m-90%), and the Cunningham-Faulkner treadmill test (C-F) (12.8 km.h-1, 20% inclination to fatigue). Afterwards, participants were divided in 2 equivalent groups of 7 persons each and underwent 6 weeks of either HIIT training two times per week (HIIT), or HIIT and supplementary aerobic training two times per week (Comb). After training, 400mMax was repeated, whereas the 400m-90% was performed at pre-training intensity. Saliva samples for the determination of testosterone (TESTO) and Cortisol (CO) were collected before and 30min after the 400mMax and 400m-90%. Pre and post exercise differences between trials were analyzed using 2-way ANOVA and responses over time by 3-way ANOVA. RESULTS: Performance improvement with training in 400mMax (HIIT: 2.6 ± 0.4% vs. Comb: 1.9 ± 0.4%, p=0.23) and C-F (HIIT: 15.7 ± 1.3% vs. Comb: 13.9 ± 3.9%, p=0.66) was similar between groups. In 400m-90% the TESTO/CO ratio increased after training only in Comb (Pre-Training: 7.0 ± 2.2 vs. Post-Training: 13.4 ± 2.2, p=0.045), while CO was higher (p=0.016) after training in HIIT (13.6 ± 1.5 ng.ml-1) compared to Comb (8.4 ± 1.5 ng.ml-1). Higher hormonal increases (p<0.05) with exercise were observed in 400mMax compared to 400m-90% irrespective of training (pre/post training) and type of group (HIIT/Comb). No other hormonal differences were detected between groups. The increase of lactate concentration (post-pre exercise difference) 3 min after 400mMax (Comb: 9.6 ± 0.6 mmol.l-1 vs. HIIT: 12.2 ± 0.6 mmol.l-1; p=0.04) and C-F (Comb: 12.1 ± 0.4 mmol.l-1 vs. HIIT: 15.4 ± 0.5 mmol.l-1; p=0.012) was lower after training in Comb compared to HIIT. During the 3-min recovery, mean percentage heart rate was lower (p<0.001) in Comb (75 ± 1%) compared to HIIT (80 ± 1%) in 400mMax. CONCLUSIONS: Comb training possibly attenuated CO response 30min post-exercise in 400m-90%. Also, the Comb training did not further improve performance in 400mMax and C-F compared to HIIT but probably induced adaptations that facilitated the faster blood lactate and heart rate recovery.