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Interval Walking Training and Nutritional Intake to Increase Plasma Volume in Elderly

Uchida Koji; Kamijo, Yoshi-ichiro; Ikegawa, Shigeki; Hamada, Koichiro; Masuki, Shizue; Nose, Hiroshi
Medicine & Science in Sports & Exercise: Post Acceptance: August 31, 2017
doi: 10.1249/MSS.0000000000001416
Original Investigation: PDF Only

ABSTRACTPurposeAerobic training-induced plasma volume (PV) expansion improves thermoregulation, and carbohydrate (CHO) + whey protein supplementation enhanced the effects in older people; however, these were suggested by studies on gym-based cycling training but not on home-based interval walking training (IWT). Moreover, long-term walking training effects on PV remain unknown.MethodsSeventeen male and 10 female subjects (~69 yr), having performed IWT for ≥24 months before the study, were used. After pre-intervention measurement (PRE) of PV, plasma albumin content (Albcont), fasting glucose concentration ([Glc]f), and HbA1c, the subjects were randomly divided into two groups: CHO and Pro-CHO, either consuming CHO (22.5 g) alone or CHO (15 g) + whey protein (10 g), respectively, during additional 5-month IWT from May to November, 2009. After the additional IWT, we measured the same variables again (post-intervention measurement, POST).ResultsThe baseline PV and Albcont were significantly correlated with the number of IWT days for the 12 months preceding PRE (r=0.716, P<0.001 and r=0.671, P<0.001, respectively). In POST, PV and Albcont, marginally decreased in CHO from the baselines (P=0.081 and P=0.130, respectively) with increased HbA1c (P<0.001) after correction for the baseline [Glc]f by ANCOVA, but these values remained unchanged in Pro-CHO (both, P>0.74), with significant differences in the changes between groups (P=0.020, P=0.041, and P=0.018 respectively).ConclusionPV was proportional to the number of IWT days for 12 months and a CHO + whey protein supplementation during the 5-month IWT prevented PV reduction for the period of no supplementation, which might be partially linked with blood glucose control mechanisms.

Purpose

Aerobic training-induced plasma volume (PV) expansion improves thermoregulation, and carbohydrate (CHO) + whey protein supplementation enhanced the effects in older people; however, these were suggested by studies on gym-based cycling training but not on home-based interval walking training (IWT). Moreover, long-term walking training effects on PV remain unknown.

Methods

Seventeen male and 10 female subjects (~69 yr), having performed IWT for ≥24 months before the study, were used. After pre-intervention measurement (PRE) of PV, plasma albumin content (Albcont), fasting glucose concentration ([Glc]f), and HbA1c, the subjects were randomly divided into two groups: CHO and Pro-CHO, either consuming CHO (22.5 g) alone or CHO (15 g) + whey protein (10 g), respectively, during additional 5-month IWT from May to November, 2009. After the additional IWT, we measured the same variables again (post-intervention measurement, POST).

Results

The baseline PV and Albcont were significantly correlated with the number of IWT days for the 12 months preceding PRE (r=0.716, P<0.001 and r=0.671, P<0.001, respectively). In POST, PV and Albcont, marginally decreased in CHO from the baselines (P=0.081 and P=0.130, respectively) with increased HbA1c (P<0.001) after correction for the baseline [Glc]f by ANCOVA, but these values remained unchanged in Pro-CHO (both, P>0.74), with significant differences in the changes between groups (P=0.020, P=0.041, and P=0.018 respectively).

Conclusion

PV was proportional to the number of IWT days for 12 months and a CHO + whey protein supplementation during the 5-month IWT prevented PV reduction for the period of no supplementation, which might be partially linked with blood glucose control mechanisms.

Address correspondence to: Hiroshi Nose, M.D, Ph.D. Department of Sports Medical Sciences, Shinshu University Graduate School of Medicine and Institute for Biomedical Sciences, 3-1-1 Asahi Matsumoto 390-8621, Japan. E-mail: nosehir@shinshu-u.ac.jp

The present address for Y. Kamijo is Department of Rehabilitation Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-8509, Japan.

This study was supported by grants from the Japan Society for the Promotion of Science (21650168 & 24240089). The authors thank all the volunteers for their participation in this study. No conflicts of interest, financial or otherwise, are declared by the authors. The results of the present study do not constitute endorsement by the American College of Sports Medicine. The results of the study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation.

Accepted for Publication: 18 August 2017

© 2017 American College of Sports Medicine