The Effect of Different High-Intensity Periodization Models on Endurance Adaptations.
This study aimed to compare the effects of three different high-intensity training (HIT) models, balanced for total load but differing in training plan progression, on endurance adaptations.



Sixty-three cyclists (peak oxygen uptake (V˙O2peak) 61.3 ± 5.8 mL·kg·min) were randomized to three training groups and instructed to follow a 12-wk training program consisting of 24 interval sessions, a high volume of low-intensity training, and laboratory testing. The increasing HIT group (n = 23) performed interval training as 4 × 16 min in weeks 1-4, 4 × 8 min in weeks 5-8, and 4 × 4 min in weeks 9-12. The decreasing HIT group (n = 20) performed interval sessions in the opposite mesocycle order as the increasing HIT group, and the mixed HIT group (n = 20) performed the interval prescriptions in a mixed distribution in all mesocycles. Interval sessions were prescribed as maximal session efforts and executed at mean values 4.7, 9.2, and 12.7 mmol·L blood lactate in 4 × 16-, 4 × 8-, and 4 × 4-min sessions, respectively (P < 0.001). Pre- and postintervention, cyclists were tested for mean power during a 40-min all-out trial, peak power output during incremental testing to exhaustion, V˙O2peak, and power at 4 mmol·L lactate.



All groups improved 5%-10% in mean power during a 40-min all-out trial, peak power output, and V˙O2peak postintervention (P < 0.05), but no adaptation differences emerged among the three training groups (P > 0.05). Further, an individual response analysis indicated similar likelihood of large, moderate, or nonresponses, respectively, in response to each training group (P > 0.05).



This study suggests that organizing different interval sessions in a specific periodized mesocycle order or in a mixed distribution during a 12-wk training period has little or no effect on training adaptation when the overall training load is the same.
1Faculty of Health and Sport Sciences, University of Agder, Kristiansand, NORWAY; 2The Norwegian Olympic Federation, Oslo, NORWAY; 3Section for Sport Science, Lillehammer University College, Lillehammer, NORWAY; and 4Centre for Elite Sports Research, Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, NORWAY.
Øystein
Ø
Sylta
Espen
E
Tønnessen
Daniel
D
Hammarström
Jørgen
J
Danielsen
Knut
K
Skovereng
Troels
T
Ravn
Bent R
BR
Rønnestad
Øyvind
Ø
Sandbakk
Stephen
S
Seiler
D000222:Adaptation, Physiological; D001642:Bicycling / Q000502:physiology; D015992:Body Mass Index; D005080:Exercise Test; D006801:Humans; D010101:Oxygen Consumption / Q000502:physiology; D064797:Physical Conditioning, Human / Q000379:methods*; D010807:Physical Endurance / Q000502:physiology*; D013997:Time Factors