I’ve been finding it more and more difficult to do longer rides in the heat lately.
I did a 60-miler on Saturday and it was over 100 degrees F throughout the ride. I found myself taking in LOTS of fluid and I noticed fatigue sooner than usual.
Should I be taking salt tablets on rides like these? If so, when do I take them, how often, and how many should I take? Do you take salt tablets on your shorter rides as well , or just on your long ride?
Also, should I be taking salt tablets for my run training?
Thanks!
Probably not.
Clin J Sport Med. 2002 Sep;12(5):279-84.
Oral salt supplementation during ultradistance exercise.
Speedy DB, Thompson JM, Rodgers I, Collins M, Sharwood K, Noakes TD.
SourceDepartment of General Practice and Primary Care, University of Auckland, New Zealand. dalespeedy@e3.net.nz
Erratum in
Clin J Sport Med. 2003 Jan;13(1):67…
AbstractOBJECTIVE: The objective of this study was to determine whether sodium supplementation 1) influences changes in body weight, serum sodium , and plasma volume (PV), and 2) prevents hyponatremia in Ironman triathletes.
SETTING: The study was carried out at the South African Ironman triathlon.
PARTICIPANTS: Thirty-eight athletes competing in the triathlon were given salt tablets to ingest during the race. Data collected from these athletes were compared with data from athletes not given salt .
INTERVENTIONS: Salt tablets were given to the SI group to provide approximately 700 mg/h of sodium.
MAIN OUTCOME MEASUREMENTS: Serum sodium, hemoglobin, and hematocrit were measured at race registration and after the race. Weights were measured before and after the race. Members of SI were retrospectively matched to subjects in NS for 1) weight change and 2) pre-race .
RESULTS: The SI group developed a 3.3-kg weight loss (p < 0.0001) and significantly increased their (delta 1.52 mmol/L; p = 0.005). When matched for weight change during the race, SI increased their compared with NS (mean 1.52 versus 0.04 mmol/L), but this did not reach statistical significance (p = 0.08). When matched for pre-race , SI had a significantly smaller percent body weight loss than NS (-4.3% versus -5.1%; p = 0.04). There was no significant difference in the increase of in both groups (1.57 versus 0.84 mmol/L). PV increased equally in both groups. None of the subjects finished the race with < 135 mmol/L.
CONCLUSIONS: Sodium ingestion was associated with a decrease in the extent of weight loss during the race. There was no evidence that sodium ingestion significantly influenced changes in or PV more than fluid replacement alone in the Ironman triathletes in this study. Sodium supplementation was not necessary to prevent the development of hyponatremia in these athletes who lost weight, indicating that they had only partially replaced their fluid and other losses during the Ironman triathlon
Br J Sports Med. 2006 Mar;40(3):255-9.
Sodium supplementation is not required to maintain serum sodium concentrations during an Ironman triathlon.
Hew-Butler TD, Sharwood K, Collins M, Speedy D, Noakes T.
SourceUniversity of Cape Town, Newlands, Cape Town, South Africa. thew@sports.uct.ac.za
AbstractCONTEXT: Critical assessment of recommendations that athletes consume additional sodium during athletic events.
OBJECTIVE: To evaluate if sodium supplementation is necessary to maintain serum sodium concentrations during prolonged endurance activity and prevent the development of hyponatraemia.
DESIGN: Prospective randomised trial of athletes receiving sodium (620 mg table salt), placebo (596 mg starch), or no supplementation during a triathlon. The sodium and placebo tablets were taken ad libitum, with the suggested range of 1-4 per hour.
SETTING: The 2001 Cape Town Ironman triathlon (3.8 km swim, 180 km cycle, 42.2 km run).
SUBJECTS: A total of 413 triathletes completing the Ironman race.
MAIN OUTCOME MEASURES: Sodium supplementation was not necessary to maintain serum sodium concentrations in athletes completing an Ironman triathlon nor required to prevent hyponatraemia from occurring in athletes who did not ingest supplemental sodium during the race.
RESULTS: Subjects in the sodium supplementation group ingested an additional 3.6 (2.0) g (156 (88) mmol) sodium during the race (all values are mean (SD)). There were no significant differences between the sodium, placebo, and no supplementation groups with regard to age, finishing time, serum sodium concentration before and after the race, weight before the race, weight change during the race, and rectal temperature, systolic and diastolic blood pressure after the race. The sodium supplementation group consumed 14.7 (8.3) tablets, and the placebo group took 15.8 (10.1) tablets (p = 0.55; NS).
CONCLUSIONS: Ad libitum sodium supplementation was not necessary to preserve serum sodium concentrations in athletes competing for about 12 hours in an Ironman triathlon. The Institute of Medicine’s recommended daily adequate intake of sodium (1.5 g/65 mmol) seems sufficient for a healthy person without further need to supplement during athletic activity.