Sirpa Manderoos

Nordic walking decreased circulating chemerin and leptin concentrations in middle-aged men with impaired glucose regulation

Abstract Background. Dysfunction of adipose tissue is one of the major factors leading to insulin resistance. Altered adipokine concentration is an early sign of adipose tissue dysfunction. The aim of this study was to assess the impact of exercise intervention on adipokine profile, glycemic control, and risk factors of the metabolic syndrome (MeS) in men with impaired glucose regulation (IGR). Methods. Overweight and obese men with IGR (n =144) aged 40–65 years were studied at baseline and at 12 weeks in a randomized controlled multicenter intervention study. BMI varied from 25.1 to 34.9. The subjects were randomized into one of three groups: 1) a control group (C; n =47), 2) a Nordic walking group (NW; n =48), or 3) a resistance training group (RT; n =49). Results. Leptin concentrations decreased in the NW group compared to both other groups. Both types of exercise intervention significantly decreased serum chemerin concentrations compared to the C group. In the NW group also body fat percentage, fatty liver index (FLI), and total and LDL cholesterol concentrations decreased compared to the RT group. Conclusions. Nordic walking intervention seems to decrease chemerin and leptin levels, and subjects in this intervention group achieved the most beneficial effects on components of MeS.

Unfavorable influence of structured exercise program on total leisure‐time physical activity

In randomized controlled trials (RCTs), with customized structured physical exercise activity (SPEA) interventions, the dose of leisure‐time physical activity (LTPA) should exceed the LTPA dose of the nonexercising control (C) group. This increase is required to substantiate health improvements achievable by exercise. We aimed to compare the dose of SPEA, LTPA, and total LTPA (SPEA + LTPA) between a randomized Nordic walking (NW) group, a power‐type resistance training (RT) group, and a C group during a 12‐week exercise intervention in obese middle‐aged men (n = 144) with impaired glucose regulation. The dose of physical activity was measured with diaries using metabolic equivalents. No significant difference (P > 0.107) between the groups was found in volume of total LTPA. The volume of LTPA was, however, significantly higher (P < 0.050) in the C group than in the NW group, but not compared with the RT group. These results indicate that structured exercise does not automatically increase the total LTPA level, possibly, as a result of compensation of LTPA with structured exercise or spontaneous activation of the C group. Thus, the dose of total LTPA and the possible changes in spontaneous LTPA should be taken into account when implementing a RCT design with exercise intervention.

Unfavorable influence of structured exercise program on total leisure- time physical activity

In randomized controlled trials (RCTs), with customized structured physical exercise activity (SPEA) interventions, the dose of leisure‐time physical activity (LTPA) should exceed the LTPA dose of the nonexercising control (C) group. This increase is required to substantiate health improvements achievable by exercise. We aimed to compare the dose of SPEA, LTPA, and total LTPA (SPEA + LTPA) between a randomized Nordic walking (NW) group, a power‐type resistance training (RT) group, and a C group during a 12‐week exercise intervention in obese middle‐aged men (n = 144) with impaired glucose regulation. The dose of physical activity was measured with diaries using metabolic equivalents. No significant difference (P > 0.107) between the groups was found in volume of total LTPA. The volume of LTPA was, however, significantly higher (P < 0.050) in the C group than in the NW group, but not compared with the RT group. These results indicate that structured exercise does not automatically increase the total LTPA level, possibly, as a result of compensation of LTPA with structured exercise or spontaneous activation of the C group. Thus, the dose of total LTPA and the possible changes in spontaneous LTPA should be taken into account when implementing a RCT design with exercise intervention.

A New Agility Test for Adults: Its Test-Retest Reliability and Minimal Detectable Change in Untrained Women and Men Aged 28-55.

Abstract Manderoos, SA, Vaara, ME, Mäki, PJ, Mälkiä, EA, Aunola, SK, and Karppi, S-L. A new agility test for adults: its test–retest reliability and minimal detectable change in untrained women and men aged 28−55. J Strength Cond Res 30(8): 2226–2234, 2016—The aims of this study were to present a new Agility Test for Adults (ATA), to investigate its test–retest reliability and to quantify minimal detectable change at the 95% confidence interval (MDC95). Both the relative and absolute reliabilities were evaluated. Altogether 52 healthy untrained volunteers (25 women: age 43.3 ± 6.6 years; 27 men: age 42.8 ± 7.2 years) were recruited into the study. The subjects performed 3 ATA tests repeated after 2 different intervals: the first test session was baseline, session 2 was a week later, and session 3 was half an hour after session 2. The intraclass correlation coefficient and the SEM of the performance time of ATA were 0.91 and 0.27 seconds (same day), 0.94 and 0.20 seconds (1 week) for women, and 0.95, 0.13 seconds, and 0.94, 0.19 seconds for men, respectively. MDC95 was 0.76 seconds (same day) and 0.56 seconds (1 week) for women, and respectively 0.37 and 0.51 seconds for men. The results showed that ATA is stable and reliable when evaluating agility characteristics in untrained adults. The properties of ATA make it appropriate for screening people to find early signs of declined agility and allow possibility to clinicians and physical trainers to monitor true changes in performance time at agility test by applying the knowledge of MDC95 coefficient. Furthermore, ATA can give tips for planning appropriate exercise programes to prevent clumsiness and falls with more serious consequences among aging people.

Mobility and muscle strength in male former elite endurance and power athletes aged 66−91 years

The aim of this cross‐sectional study was to compare mobility and muscle strength in male former elite endurance and power athletes aged 66−91 years (n = 150; 50 men in both former elite athlete groups and in their control group). Agility, dynamic balance, walking speed, chair stand, self‐rated balance confidence (ABC‐scale), jumping height, and handgrip strength were assessed. Former elite power athletes had better agility performance time than the controls (age‐ and body mass index, BMI‐adjusted mean difference −3.6 s; 95% CI −6.3, −0.8). Adjustment for current leisure time physical activity (LTPA) and prevalence of diseases made this difference non‐significant (P = 0.214). The subjects in the power sports group jumped higher than the men in the control group (age‐ and BMI‐adjusted mean differences for vertical squat jump, VSJ 4.4 cm; 95% CI 2.0, 6.8; for countermovement jump, CMJ 4.0 cm; 95% CI 1.7, 6.4). Taking current LTPA and chronic diseases for adjusting process did not improve explorative power of the model. No significant differences between the groups were found in the performances evaluating dynamic balance, walking speed, chair stand, ABC‐scale, or handgrip strength. In conclusion, power athletes among the aged former elite sportsmen had greater explosive force production in their lower extremities than the men in the control group.

Plasma irisin is increased following 12 weeks of Nordic walking and associates with glucose homoeostasis in overweight/obese men with impaired glucose regulation

Abstract Irisin is a myokine that is thought to be secreted in response to exercise that may help to prevent obesity and maintain normal glucose metabolism. In this study we investigated the associations between irisin and glucose homeostasis in middle-aged, overweight and obese men (n =  144) with impaired glucose regulation, and the impact of exercise training on these relationships. The participants underwent 12 weeks of resistance or aerobic (Nordic walking) exercise training three times per week, 60 minutes per session. Venous blood (n = 105) and skeletal muscle samples (n = 45) were obtained at baseline and post-intervention. Compared to controls, Nordic walking, but not resistance training, increased irisin levels in plasma (9.6 ± 4.2%, P = 0.014; 8.7 ±  4.9%, P = 0.087; respectively) compared to controls. When considering all subjects, baseline irisin correlated positively with atherogenic index of plasma (r = 0.244, P = 0.013) and 2-hour insulin levels (r = 0.214, P = 0.028), and negatively with age (r = −0.262, P = 0.007), adiponectin (r = −0.240, P = 0.014) and McAuley index (r = −0.259, P = 0.008). Training-induced FNDC5 mRNA changes were negatively correlated with HbA1c (r = −0.527, P = 0.030) in the resistance training group and with chemerin in the Nordic walking group (r = −0.615, P = 0.033). In conclusion, 12-weeks of Nordic walking was more effective than resistance training in elevating plasma irisin, in middle-aged men with impaired glucose tolerance. Thus, the change in irisin in response to exercise training varied by the type of exercise but showed limited association with improvements in glucose homeostasis.