Polymorphonuclear leucocyte phagocytic function, γδ T-lymphocytes and testosterone as separate stress-responsive markers of prolonged, high-intensity training programs

Abstract

Excessive exercise with limited recovery may lead to detrimental states of overreaching or the overtraining syndrome. Chronic maladaptation in endocrine and immune mechanisms occur with the incidence of these states. Exercise-induced cortisol and testosterone responses have been proposed as biomarkers of overreaching, with blunted responses following intensified-training periods. Yet, limited information on the effects of overreaching in immunity is available. Healthy individuals completed a 30-min running protocol (the RPE TP ) before and after a 12-day intensified-training period. Blood and saliva were collected before, after and 30min after RPE TP at pre-training and post-training. Plasma and salivary cortisol and testosterone, leucocyte proliferation and polymorphonuclear leucocyte phagocytic activity were examined. Plasma and salivary cortisol were acutely unaffected pre-training (−14% and 0%, p ​> ​0.05) and post-training (−14% and +46%, p ​> ​0.05). Comparing pre-training with post-training, blunted responses were observed in plasma testosterone (43%–19%, p ​< ​0.05) and salivary testosterone (55%–24%, p ​> ​0.05). No acute or resting changes in total leucocyte counts or most leucocyte subsets occurred pre-training or post-training. Yet, a 194% acute elevation in γδ T-lymphocyte number occurred pre-training ( p ​< ​0.05), and average resting concentrations were 174% higher post-training. Baseline phagocytic activity was 47% lower post-training ( p ​< ​0.05). Intensified training was detrimental, significantly reducing phagocytic activity. Testosterone blunted post-training, indicating an excessive training-related hypothalamic-pituitary gonadal dysfunction. The γδ T-lymphocytes sensitivity to exercise was noted, rendering it as a potential stress-responsive cellular marker. The usefulness of the RPE TP to track the onset of overreaching is proposed.

Comparison of the lymphocyte response to interval exercise versus continuous exercise in recreationally trained men

“…The superior benefits of HIIE to improve aerobic capacity are well-documented ( Helgerud et al., 2007 ; Ní Chéilleachair et al., 2017 ; Rønnestad et al., 2016 ); however, a common concern among athletes, coaches, and scientists is whether the high training loads associated with repeated intervals within a short period of time could compromise immune function and increase susceptibility to infections. These concerns are justified, given that high-intensity exercise has been shown to increase oxidative stress and increase lymphocyte apoptosis ( Navalta et al., 2007 , 2009 , 2012 ; Mars et al., 1998 ; Leal et al., 2021 ). It has been suggested that this exercise-induced increase in lymphocyte apoptosis may contribute to the declines in circulating lymphocyte cell counts ( Mars et al., 1998 ).…”

“…Notwithstanding, similar to the present study, no trial differences were observed in LY, CD3 + T or CD8 + T cell counts ( Turner et al., 2016 ). This indicates that CD56 dim NK cells may be more sensitive to differences in acute training variables than other lymphocyte subsets ( Leal et al., 2021 ). A key limitation of this study was that post-exercise blood samples were limited to 30 ​min post-exercise.…”

The Potential Modulatory Effects of Exercise on Skeletal Muscle Redox Status in Chronic Kidney Disease

“…Similar to unaccustomed exercise in CKD patients, it can be partially observed with the incidence of the overtraining syndrome (OTS), in which a state of chronic OS is observed due to intensified training/competition and inadequate post-exercise/competition recovery, leading to a persistent fatigue and decline in physical performance [ 200 ]. Moreover, a study from our group showed that, after intensified training, leukocyte phagocytic activity decreases and testosterone levels were blunted, showing dysfunction of inflammatory response and at the hypothalamic-pituitary gonadal axis [ 201 ]. Interestingly, in OTS are also observed OS blood markers, for example, persistence for more than a month of a reduced glutathione depletion after an ultra-endurance marathon [ 202 ].…”

Lymphocyte and dendritic cell response to a period of intensified training in young healthy humans and rodents: A systematic review and meta-analysis

“…(Figure 1) Across the 57 included studies (Table 2), the variables used to assess immune cell changes included immune cell counts (Ferry et al, 1990;Fry et al, 1992;Ndon et al, 1992;Baj et al, 1994;Baum et al, 1994;Pizza et al, 1995;Mitchell et al, 1996;Mujika et al, 1996;Hack et al, 1997;Bury et al, 1998;Rebelo et al, 1998;Mueller, 2001;Ronsen et al, 2001;Dressendorfer et al, 2002;Halson et al, 2003;Peake et al, 2003;Lancaster et al, 2004;Meyer et al, 2004;Smith and Myburgh, 2006;Shing et al, 2007;Tanimura et al, 2009;Bresciani et al, 2011;Wang et al, 2011;Wang et al, 2011;Borges et al, 2012;Witard et al, 2012;Heisterberg et al, 2013;Li et al, 2013;Weng et al, 2013;Louis et al, 2016;Sheyklouvand et al, 2018;Poffe et al, 2019;Chung et al, 2021;Leal et al, 2021), lymphocyte proliferation (Hoffman-Goetz, 1986;Watson, 1986;Hoffman-Goetz et al, 1988;Mitchell et al, 1996;Bury et al, 1998;…”