長時間持久運動後の疲労困憊と
ビタミンＢ1動態について

Relation Between Vitamin B1 and Exhaustive
Mood State After Ultraendurance Exercise

by

Yuko Odagiri, Teruichi Shimomitsu, Toshihito Katsumura,
Yumiko Ohya, Yoshikazu Takanami
Department of Preventive Medicine and Public Health
Tokyo Medical College

ABSTRACT

The purpose of this study was to investigate the relationship between changes in vitamin B1 (B1)and psychological fatigue after ultraendurance exercise. Serum levels of B1(S-B1)and erythrocyte transketolase(ETK),as well as blood glucose,lactate,free fatty acid,myoglobin,and creatin kinase were measured in 24 Japanese male athletes (37.9±9.2 yrs) who completed triathlon race (3.9km swim, 180km bike,42.2km marathon). Profile of Mood State(POMS) test was performed for the assessment for psychological fatigue. These tests were conducted two days before,immediately following,and one day after the race. Urinary excretion of B1 during night was measured one day before and on the race day. Food and supplement records were obtained two days before and on the race day to calculate B1 intake. Sixteen out of 24 subjects took wore than 2mg B1 by supplement, which is the recommended dosage for endurance sport athletes during training periods (S(+)group,). These 16 athletes were compared with rest of the subjects (s(-)group,n=8). There were no sinificant group difference in age, physical characteristics,race results, pre- and post-race myoglobin, creatin kinase, or ETK. Mean pre-race S-B1 of S(-) group was significantly lower than that of S(+)
(p＜0.01) and tended to be lower immediately post-race(p=0.086). While, mean change values of S-B1 were not significantly different between groups.
Urinary excretion of B1 in S(-) group is tended to be lower compared with S(+) (p=0.076).
Mean post-rase lactate lactate was significant group diference in each POMS scores, however prevalence of severe exhaustive state was tended to be higher in S(-)group (p=0.091). The data show that B1 supplement more than the recommended dosage is related to relatively higher levels of S-B1, and is suggested to be effective to prevent severe exhaustion after ultraendurance exercise.

　要　旨

　本研究の目的は、長時間持久運動におけるビタミンＢ１の動態と疲労度との関係を検討することである。トライアスロン（水泳３．９ｋｍ、自転車１８０．２ｋｍ、マラソン４２．２ｋｍ）を完走した成人男子２４名（３７．９±９．２歳）を対象とし、競技２日前、競技直後、および翌日に血糖、乳酸、遊離脂肪酸、ミオグロビン、クレアチンキナーゼ、血中ビタミンＢ１量、溶赤血球中トランスケトラーゼ活性と、尿中ビタミンＢ１排泄量の測定、気分プロフィール検査（ＰＯＭＳ）、競技前と競技当日に栄養調査を行なった
栄養調査の結果から、持久運動選手に推奨されているビタミンＢ１摂取量２ｍｇ以上をサプリメントから習慣的摂取している群（充足群、ｎ＝１６）と摂取していない群（不足群、ｎ＝８）に分類した。２群間で年齢、体格、競技成績、ミオグロビン、クレアチンキナーゼ、溶赤血球中トランスケトラーゼ活性に有意差はなかった。血中ビタミンＢ１濃度は、競技前、不足群において充足群より有意に（ｐ＜０．０１）低く、競技直後も低い傾向が認められた（ｐ＝０．０８６）。しかし、血中ビタミンＢ１濃度の競技直後の上昇度は２群間で有意な差はなかった。尿中のビタミンＢ１排泄量は、競技後に不足群において低い傾向を認めた（ｐ＝０．０７６）。また、不足群では充足群より競技直後の乳酸値が有意に高値を示した。ＰＯＭＳ各尺度得点および疲労困憊群の出現率は２群間で差がなかったが、極度の疲労困憊状態を示した者の出現率は不足群において高い傾向を認めた（ｐ＝０．０９１）。
以上より、推奨量以上のビタミンＢ１の習慣的な摂取は競技前および競技直後の血中ビタミンＢ１濃度の高値と関連し、長時間持久運動による極度の疲労困憊状態の出現を予防する可能性が示唆された。