Comparison Of Sprint Interval Training,Continuous Training And Blood Flow Restriction On Acute Physiological Characteristics And Effects

Purpose: The design of protocols and intervention effects of high intensity interval training and blood flow restriction training have received extensive attention,especially in the last decade,they have been the hotspots and frontiers of competitive sports training;at the same time,they are also kinds of topics that are easily affected and limited by research conditions.In recent years,there are still many controversies and difficulties in the subject of influence and limitation,which need to be continuously explored and developed.Therefore,research on the acute physiological response and training effects of high intensity interval training and blood flow restriction training is important for sports training,including competitive sports,exercise and rehabilitation training.Due to the variety of high intensity interval training,this study focused on sprint interval training(SIT).To explore the similarities and differences of the workloads and energy consumption between SIT protocols with different recovery duration,and to supply theoretical reference for the application of SIT.Comparing the acute physiological characteristics and effects of SIT,continuous training(CT)and continuous training combined with intermittent blood flow restriction(CT+B).Hope to provide a new research perspective and experimental basis for athletes and publics.Methods: 1.The acute physiological characteristics of different sprint interval training(Study 1)12 active young men took part in a 2000 m time trial and seven different sprint interval training sessions(including 18*{10s+80s} SIT1,9*{20s+160s} SIT2,6*{30s+240s} SIT3,9*{30s+150s} SIT4,18*{30s+60s} SIT5,6*{30s+150s} SIT6,6*{30s+60s} SIT7)on rowing ergometer.The blood lactate,rating of perceived exertion(RPE),heart rate,energy consumption,total distance,stroke rate,velocity and power characteristics were analyzed.According to the total energy consumption and total distance,one SIT protocol was selected as the template to draw up the CT+B and CT protocols and used in Study 2 and Study 3.2.The acute physiological characteristics of sprint interval training,continuous training and continuous training combined with intermittent blood flow restriction(Study 2)10 active young men completed a 2000 m time trial and three different training programs(SIT,CT and CT+B)on rowing ergometer.The durations of SIT with 9 sets of 20 s sprint(same as the SIT2 in the Study 1),CT+B with 9 sets of blood flow restriction(BFR)and basal CT were 27 min.The blood lactate,RPE,heart rate,energy consumption,tissue saturation index(TSI),total distance,stroke rate,velocity and power characteristics were analyzed.3.The effects of sprint interval training,continuous training and continuous training combined with intermittent blood flow restriction on body composition,aerobic and anaerobic capacity in active young males(Study 3)45 active young men were randomly assigned into 4 groups,control(CON)group,SIT group,CT group and CT+B group.All participants took part in the baseline test,including weight,body fat percentage,the duration of 2000 m,maximal oxygen uptake,maximal heart rate,maximal blood lactate,accumulated blood lactate,maximal anaerobic capacity and 30 s average anaerobic capacity.Then,the participants in three training groups took part in 4 weeks rowing training with 3 times per week,and the CON group did not take part in any training intervention.After 4 weeks,all subjects performed the same tests as the baseline,and all data were analyzed.Results: 1.The acute physiological characteristics of different sprint interval training Compared with SIT3,other protocols had the following differences:(1)Maximum blood lactate(P < 0.001),cumulative blood lactate(P = 0.015),and glycolytic energy supply ratio(P = 0.018)were significantly lower in SIT1 than in SIT3,but total distance(P = 0.040)and average velocity(P = 0.040)were significantly higher.(2)SIT2 had significantly lower maximum blood lactate than SIT3(P = 0.006),but significantly higher maximum power(P = 0.020),mean power during the sprint work period(P = 0.012),total energy consumption(P = 0.041)and energy consumption per minute(P = 0.041)than SIT3.(3)No differences were observed in SIT4 compared to SIT3 for the above metrics(P > 0.05).(4)SIT5 had significantly higher mean heart rate(P < 0.001),total energy consumption(P = 0.003)and energy consumption per minute(P = 0.003)than SIT3,but significantly lower mean paddle frequency(P = 0.045),mean peak power(P = 0.002)and mean power during the sprint work period(P < 0.001)than SIT3.(5)SIT6 had significantly lower mean heart rate(P = 0.018),total distance(P < 0.001),aerobic energy supply ratio(P = 0.001)and total energy consumption(P < 0.001)than SIT3,but significantly higher maximum power(P = 0.009),mean peak power(P = 0.010)and glycolytic energy supply ratio(P < 0.001)than SIT3.(6)SIT7 had significantly lower total distance(P < 0.001),aerobic energy supply ratio(P < 0.001)and total energy consumption(P < 0.001)than SIT3,but significantly higher maximum power(P = 0.015),phosphagen energy supply ratio(P = 0.013),glycolytic energy supply ratio(P < 0.001)and energy consumption per minute(P < 0.001)than SIT3.The comparison revealed that the heterogeneity of work period(sprint)duration and recovery period duration led to the abovementioned differences in internal load,external load and energy consumption.Meanwhile,total energy consumption was used as the first criterion for SIT scheme screening in the subsequent experiments,and only SIT2 and SIT5 schemes had significantly higher total energy consumption than the conventional SIT3 scheme(P < 0.05);since there was no significant variability between the total energy consumption of SIT2 and SIT5 schemes(P > 0.05),total distance was selected as the second screening criterion,and SIT2 had significantly higher total distance than SIT5(P = 0.028);finally,SIT2 was selected as the SIT scheme for Study 2 and Study 3.2.The acute physiological characteristics of sprint interval training,continuous training and continuous training combined with intermittent blood flow restriction(1)Compared with SIT,the internal load characteristics,external load characteristics and total energy consumption of CT and CT+B showed the following differences: maximum blood lactate,cumulative blood lactate and RPE were significantly lower in CT and CT+B than in SIT(P < 0.05),but mean heart rate,total distance,average velocity,mean power and total energy consumption were significantly higher than in SIT(P < 0.05).(2)By comparing the load characteristics and total energy consumption of CT+B and CT,no significant differences were found in the internal workloads(maximal blood lactate,cumulative blood lactate,RPE,mean heart rate),external workloads(total distance,mean paddle frequency,average velocity and mean power)and total energy consumption between the two training modalities(P > 0.05).(3)The most significant difference among the three training modalities came from muscle oxygen saturation,which decreased significantly more in CT(P = 0.015)and CT+B(P = 0.001)than in SIT and significantly more in CT+B(P = 0.041);in addition,the decrease in muscle oxygen saturation troughs was significantly smaller in CT than in SIT(P = 0.010)and CT+B(P = 0.037),while there was no significant difference between SIT and CT+B(P > 0.05).3.The effects of sprint interval training,continuous training and continuous training combined with intermittent blood flow restriction on body composition,aerobic capacity and anaerobic capacity in active young males(1)Body fat percentage: SIT group(P = 0.012),CT group(P < 0.001)and CT+B group(P = 0.02)were decreased.(2)2000m duration: SIT group(P < 0.001),CT group(P = 0.001)and CT+B group(P < 0.001)were reduced.(3)Maximum oxygen uptake: only the SIT group(P < 0.001)and CT+B group(P = 0.026)were increased.(4)Maximum anaerobic capacity: only the SIT group(P = 0.001)and CT+B group(P = 0.006)were increased.(5)Average anaerobic capacity: only CT group(P = 0.007)and CT+B group(P = 0.001)were increased.Conclusions: 1.Comparing the similarities and differences of workloads and energy consumption between the classic SIT protocol(6*{30s+240s})and the other six SIT protocols with different recovery periods,it provides theoretical basis for the selection and application of SIT.2.SIT(9*{20s+160s})is the higher one on total energy consumption and total distance among SIT protocols,it has the function of reducing the body fat percentage and improving the performance in active young men.3.Among the acute physiological characteristics of CT and CT+B,the primary difference is the change of TSI.Each set of blood flow restriction can decrease the TSI,and there is no difference between SIT and CT+B.which may be one of the reasons for better effects in CT+B than CT.4.4-week SIT,CT,and CT+B interventions can equivalently reduce body fat percentage in active young men;however,SIT and CT+B are more effective in improving cardiorespiratory fitness than CT.5.SIT and CT+B play an important role in optimizing physical fitness,which can improve body composition and cardiorespiratory fitness while considering the improvement of anaerobic capacity.it is recommended that CT+B is an alternative way to improving cardiorespiratory fitness and body composition in those who could not take part in SIT or adaptive "immune" SIT.