Tags

Type your tag names separated by a space and hit enter

Significant and serious dehydration does not affect skeletal muscle cramp threshold frequency.
Br J Sports Med. 2013 Jul; 47(11):710-4.BJ

Abstract

OBJECTIVE

Many clinicians believe that exercise-associated muscle cramps (EAMC) occur because of dehydration. Experimental research supporting this theory is lacking. Mild hypohydration (3% body mass loss) does not alter threshold frequency (TF), a measure of cramp susceptibility, when fatigue and exercise intensity are controlled. No experimental research has examined TF following significant (3-5% body mass loss) or serious hypohydration (>5% body mass loss). Determine if significant or serious hypohydration, with moderate electrolyte losses, decreases TF.

DESIGN

A prepost experimental design was used. Dominant limb flexor hallucis brevis cramp TF, cramp electromyography (EMG) amplitude and cramp intensity were measured in 10 euhydrated, unacclimated men (age=24±4 years, height=184.2±4.8 cm, mass=84.8±11.4 kg). Subjects alternated exercising with their non-dominant limb or upper body on a cycle ergometer every 15 min at a moderate intensity until 5% body mass loss or volitional exhaustion (3.8±0.8 h; 39.1±1.5°C; humidity 18.4±3%). Cramp variables were reassessed posthypohydration.

RESULTS

Subjects were well hydrated at the study's onset (urine specific gravity=1.005±0.002). They lost 4.7±0.5% of their body mass (3.9±0.5 litres of fluid), 4.0±1.5 g of Na(+) and 0.6±0.1 g K(+) via exercise-induced sweating. Significant (n=5) or serious hypohydration (n=5) did not alter cramp TF (euhydrated=15±5 Hz, hypohydrated=13±6 Hz; F1,9=3.0, p=0.12), cramp intensity (euhydrated= 94.2±41%, hypohydrated=115.9±73%; F1,9=1.9, p=0.2) or cramp EMG amplitude (euhydrated=0.18±0.06 µV, hypohydrated= 0.18±0.09 µV; F1,9=0.1, p=0.79).

CONCLUSIONS

Significant and serious hypohydration with moderate electrolyte losses does not alter cramp susceptibility when fatigue and exercise intensity are controlled. Neuromuscular control may be more important in the onset of muscle cramps than dehydration or electrolyte losses.

Authors+Show Affiliations

Departments of Health, Nutrition, and Exercise Sciences, North Dakota State University, Fargo, ND 58108-6050, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article

Language

eng

PubMed ID

23222192

Citation

Braulick, Kyle W., et al. "Significant and Serious Dehydration Does Not Affect Skeletal Muscle Cramp Threshold Frequency." British Journal of Sports Medicine, vol. 47, no. 11, 2013, pp. 710-4.
Braulick KW, Miller KC, Albrecht JM, et al. Significant and serious dehydration does not affect skeletal muscle cramp threshold frequency. Br J Sports Med. 2013;47(11):710-4.
Braulick, K. W., Miller, K. C., Albrecht, J. M., Tucker, J. M., & Deal, J. E. (2013). Significant and serious dehydration does not affect skeletal muscle cramp threshold frequency. British Journal of Sports Medicine, 47(11), 710-4. https://doi.org/10.1136/bjsports-2012-091501
Braulick KW, et al. Significant and Serious Dehydration Does Not Affect Skeletal Muscle Cramp Threshold Frequency. Br J Sports Med. 2013;47(11):710-4. PubMed PMID: 23222192.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Significant and serious dehydration does not affect skeletal muscle cramp threshold frequency. AU - Braulick,Kyle W, AU - Miller,Kevin C, AU - Albrecht,Jay M, AU - Tucker,Jared M, AU - Deal,James E, Y1 - 2012/12/06/ PY - 2012/12/11/entrez PY - 2012/12/12/pubmed PY - 2014/1/30/medline KW - Dehydration KW - Muscle cramping SP - 710 EP - 4 JF - British journal of sports medicine JO - Br J Sports Med VL - 47 IS - 11 N2 - OBJECTIVE: Many clinicians believe that exercise-associated muscle cramps (EAMC) occur because of dehydration. Experimental research supporting this theory is lacking. Mild hypohydration (3% body mass loss) does not alter threshold frequency (TF), a measure of cramp susceptibility, when fatigue and exercise intensity are controlled. No experimental research has examined TF following significant (3-5% body mass loss) or serious hypohydration (>5% body mass loss). Determine if significant or serious hypohydration, with moderate electrolyte losses, decreases TF. DESIGN: A prepost experimental design was used. Dominant limb flexor hallucis brevis cramp TF, cramp electromyography (EMG) amplitude and cramp intensity were measured in 10 euhydrated, unacclimated men (age=24±4 years, height=184.2±4.8 cm, mass=84.8±11.4 kg). Subjects alternated exercising with their non-dominant limb or upper body on a cycle ergometer every 15 min at a moderate intensity until 5% body mass loss or volitional exhaustion (3.8±0.8 h; 39.1±1.5°C; humidity 18.4±3%). Cramp variables were reassessed posthypohydration. RESULTS: Subjects were well hydrated at the study's onset (urine specific gravity=1.005±0.002). They lost 4.7±0.5% of their body mass (3.9±0.5 litres of fluid), 4.0±1.5 g of Na(+) and 0.6±0.1 g K(+) via exercise-induced sweating. Significant (n=5) or serious hypohydration (n=5) did not alter cramp TF (euhydrated=15±5 Hz, hypohydrated=13±6 Hz; F1,9=3.0, p=0.12), cramp intensity (euhydrated= 94.2±41%, hypohydrated=115.9±73%; F1,9=1.9, p=0.2) or cramp EMG amplitude (euhydrated=0.18±0.06 µV, hypohydrated= 0.18±0.09 µV; F1,9=0.1, p=0.79). CONCLUSIONS: Significant and serious hypohydration with moderate electrolyte losses does not alter cramp susceptibility when fatigue and exercise intensity are controlled. Neuromuscular control may be more important in the onset of muscle cramps than dehydration or electrolyte losses. SN - 1473-0480 UR - https://www.unboundmedicine.com/medline/citation/23222192/Significant_and_serious_dehydration_does_not_affect_skeletal_muscle_cramp_threshold_frequency_ L2 - https://bjsm.bmj.com/lookup/pmidlookup?view=long&pmid=23222192 DB - PRIME DP - Unbound Medicine ER -