Introduction
The physiological effects of single and multiday road running races have been studied extensively
and include the occurrence of rhabdomyolysis, reflected by significantly increased urinary
myoglobin (uMb), as well as increased concentrations of serum creatine phosphokinase (CPK),
high sensitivity C-reactive protein (hsCRP), cortisol and cardiac troponin-T (cTnT), dehydration
and compromised renal function. Furthermore, in hyperthermic athletes, a positive relationship
has been noted between hyperthermia, muscle damage, dehydration and pacing. The
physiological effects of a multiday trail run of similar duration to single day road races, however,
are unknown.
The side-effects of the use of statin medication for hypercholesterolaemia include muscle fatigue,
cramping and increased muscle damage. These have been found to be aggravated in endurance
athletes and it has been reported that females, especially when being medicated from a young age,
are more susceptible to these side-effects.
Objectives
1. To investigate the effect of a three-day trail run on systemic and urinary markers of muscle
damage and inflammation in recreational runners and to establish the association of dehydration
and hyperthermia with these markers.
2. To observe the effect of the three day trail run on systemic and urinary markers of muscle
damage and inflammation on an additional hypercholesterolaemic female athlete using statin
medication in combination with a lipid uptake inhibitor.
Method
Firstly, an observational cohort study was conducted on 19 recreational male (n=6) and female
(n=13) athletes during a 95km trail run over three days.
Pre-and post-stage and 24 and 72 h post-race concentrations of serum CPK, hsCRP, cortisol,
cTnT, and osmolality (sOsm) as well as uMb, changes in body mass, delayed onset muscle
soreness (DOMS) and thigh circumference (TC) were measured. Continuous recordings of heart
rate (HR) and intestinal temperature (Tintest ) were made throughout each stage.
In addition, a case report is included on one trained female endurance athlete currently being
treated for familial hypercholesterolaemia with 20 mg Aspavor and 10 mg Ezetrol daily and not
included in the above cohort, to investigate the degree of muscle damage and inflammation she
experienced as a result of participation in the three-day event.
Results:
Heart rate ranged between 77 and 83% age-predicted-maximum (APmax) and Tintest between
36.1 and 40.2 ºC during the three stages. Significant rises in mean serum CPK, hsCRP, sOsm and
blood neutrophil count reached peak concentrations of 1 488U/L, 8.91mg/l, 298mosm/L and
10.21 10^9/L (p≤0.001), respectively. No evidence of elevations in uMb and cTnT were detected.
The stage-induced increments in DOMS correlated positively with CPK, r=0.71; 95% CI [0.62,
0.78]. TC decreased significantly post S1post and S2post (p≤0.05) and a maximum mean body mass
loss of 3.09% (±1.04%) occurred during S2. There was no significant difference between nonsteroidal
anti-inflammatory drug (NSAID) users and non-users in terms of serum CPK, hsCRP,
cortisol, post race DOMS scores, running times, TC or sOsm (p>0.05). The post-pre change in
sOsm during each stage correlated inversely with the changes in % body mass, r = -0.36, 95% CI
[-0.57,-0.094] and the pooled data examining the relationship between the change of sOsm and
change in serum CPK for the three stages (n=57), revealed an insignificant positive correlation
(r= 0.034, 95% CI [-0.228, 0.291].
The maximum Tintest ranged between 38.3 º C and 40.2 º C and only exceeded 40º C in two of the
12 athletes monitored. The relationship between the change in Tintest and serum CPK was
insignificant (p>0.05) for the 11 individuals from whom complete sets of data were available (r=
0.24, 95% CI [-0.42, 0.734].
In the hypercholesterolaemic athlete, the maximum serum CPK (665U/L), hsCRP (1.9mg/Ll) and
cortisol (845nmol/L) concentrations corresponded with undetected uMb despite a maximum body
mass loss of 4.5%
Conclusion:
Three consecutive days of 95km trail running resulted in low markers of muscle damage and
inflammation, when compared to results obtained in previous single day road races of similar
duration despite the maintenance of a heart rate above 77% APmax, Tintest rising above 39o C and
mean body mass decrement of >2.0%. The unchanged concentrations of serum cTnT and uMb
confirmed the low values of the markers of muscle damage and inflammation. An insignificant
positive correlation between muscle damage and dehydration was noted.
Furthermore the daily use of 0.4 mg/kg Atorvastatin in combination with 10mg Ezetrol did not
result in the subject experiencing subjective myalgia, cramps, fatigue or increased markers of
muscle damage following her participation in the trail run. / Thesis (M.Med.Sc.)-University of KwaZulu-Natal, 2012.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/5651 |
| Date | January 2012 |
| Creators | Denissen, Emmerentia C. |
| Contributors | Peters-Futre, E. M. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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