Rest interval duration does not influence adaptations in acid/base transport proteins following 10 wk of sprint-interval training in active women.
The removal of protons (H+) produced during intense exercise is important for skeletal muscle function, yet it remains unclear how best to structure exercise training to improve muscle pH regulation. We investigated whether 4 wk of work-matched sprint-interval trining (SIT), performed 3 days/wk, with either 1 (Rest-1;n= 7) or 5 (Rest-5;n= 7) min of rest between sprints, influenced adaptations in acid/base transport protein content, nonbicarbonate muscle buffer capacity (βmin vitro), and exercise capacity in active women. Following 1 wk of posttesting, comprising a biopsy, a repeated-sprint ability (RSA) test, and a graded-exercise test, maintenance of adaptations was then studied by reducing SIT volume to 1 day/wk for a further 5 wk. After 4 wk of SIT, there was increased protein abundance of monocarboxylate transporter (MCT)-1, sodium/hydrogen exchanger (NHE)-1, and carbonic anhydrase (CA) XIV for both groups, but rest interval duration did not influence the adaptive response. In contrast, greater improvements in total work performed during the RSA test after 4 wk of SIT were evident forRest-5compared withRest-1(effect size: 0.51; 90% confidence limits ±0.37), whereas both groups had similarly modest improvements in V̇o2peakWhen training volume was reduced to 1 day/wk, enhanced acid/base transport protein abundance was maintained, although NHE1 content increased further forRest-5only. Finally, our data support intracellular lactate as a signaling molecule for inducing MCT1 expression, but neither lactate nor H+accumulation appears to be important signaling factors in MCT4 regulation.
College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia; cian.mcginley@live.vu.edu.au.|Sportscotland Institute of Sport, Stirling, Scotland.
Cian
0000-0001-5575-4262
C
McGinley
College of Sport and Exercise Science, Victoria University, Melbourne, Victoria, Australia.|Institute of Sport, Exercise, and Active Living, Victoria University, Melbourne, Victoria, Australia; and.
David J
DJ
Bishop
D000136:Acid-Base Equilibrium / Q000502:physiology*; D000222:Adaptation, Physiological / Q000502:physiology*; D000328:Adult; D027963:Chloride-Bicarbonate Antiporters; D005260:Female; D000072696:High-Intensity Interval Training / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D009124:Muscle Proteins / Q000378:metabolism; D018482:Muscle, Skeletal / Q000737:chemistry / Q000502:physiology*; D064797:Physical Conditioning, Human / Q000379:methods*; D010809:Physical Fitness; D017494:Proton Pumps / Q000378:metabolism*; D012146:Rest / Q000502:physiology
D027963:Chloride-Bicarbonate Antiporters; D009124:Muscle Proteins; D017494:Proton Pumps
detraining; intracellular buffering; lactate transport; repeated-sprint ability