Page 256 - 2021_05-Haematologica-web

Letters to the Editor
How to implement endurance exercise training in
sickle cell disease
A previous study demonstrated the safety and benefi- cial effects of moderate-intensity endurance exercise training in patients with sickle cell disease (SCD). However, this previous pilot study had several limita- tions. The most important constraint was the need for repeated measurements of blood lactate concentration in order to adjust training intensity. This approach consid- erably hinders implementation and dissemination of endurance exercise training in the general population of SCD patients. In the present study, we tested heart rate as a possible surrogate for adjustment of training inten- sity. Patients (n=15) successively performed an initial
submaximal incremental test (SIT1), 30-min moderate- intensity cycling exercises three times a week for 8 weeks, and finally another SIT (SIT2). Heart rate (HR) and blood lactate concentration ([lactate]b) were record- ed every minute during both SIT and once during train- ing sessions. [lactate]b and HR values measured during training concurred with the correlation obtained between [lactate]b and HR during the two SIT. Provided that patients’ individual [lactate]b versus HR relationship (obtained during a SIT) is known and patients are accus- tomed to cycling exercise, HR appears to be an accept- able surrogate to control and adjust intensity of endurance exercises.
SCD is the most frequent genetic disease worldwide. Vaso-occlusion and anemia, the two main consequences of the disease, induce a myriad of complications affecting
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Figure 1. Relationship between blood lactate concentration and heart rate in 15 patients with sickle cell disease during exercise. The relationship between blood lactate concentration ([lactate]b) versus heart rate (HR) relationship during a first submaximal incremental test (black circles) and a second one for two patients (gray circles, panels N and O), as well as the [lactate]b–HR pairs measured during the training sessions (open triangles). HR at the first lactate threshold (LT1) as well as at 2.5 mmol.L-1 are also reported (vertical dotted lines).
haematologica | 2021; 106(5)