Introduction Prior upper body exercise reduces the curvature constant (W) of the hyperbolic power-duration relationship without affecting critical power. This study tested the hypothesis that prior upper body exercise reduces the work done over the end-test power (WEP; analogue of W) during a 3-min all-out cycling test (3MT) without affecting the end-test power (EP; analogue of critical power). Methods Ten endurance-trained men (V ̇O2max = 62 5 mLkg -1 min -1 ) performed a 3MT without (CYC) and with (ARM-CYC) prior severe-intensity, intermittent upper body exercise. EP was calculated as the mean power output over the last 30s of the 3MT, whereas WEP was calculated as the power-time integral above EP. Results At the start of the 3MT, plasma [La -] (1.8 0.4 vs. 14.1 3.4 mmol•L -1 ) and [H + ] (42.8 3.1 vs. 58.6 5.5 nmol•L -1 ) were higher, whereas the strong ion difference ([SID]) (41.4 2.2 vs. 30.9 4.6 mmol•L -1 ) and [HCO 3 -] (27.0 1.9 vs. 16.9 3.2 mmol•L -1 ) were lower, during ARM-CYC than CYC (P < 0.010). EP was 12% lower during the 3MT of ARM-CYC (298 52 W)than CYC (338 60 W) (P < 0.001), whereas WEP was not different (CYC: 12.8 3.3 kJ vs.ARM-CYC: 13.5 4.1 kJ, P = 0.312). EP in CYC was positively correlated with the peak [H + ] (r = 0.78, P = 0008), and negatively correlated with the lowest [HCO 3 -] (r = -0.74, P = 0.015).
ConclusionThese results suggest that EP during a 3MT in endurance-trained men is sensitive to fatigue-related ionic perturbation.
Maternal dietary habits influence maternal and foetal health, representing a pathway for intervention to maximise pregnancy outcomes. Advice on energy intake is provided on a trimester basis, with no additional calories required in the first trimester and an additional 340 kcal d and 452 kcal d needed for the second and third trimesters. Energy intake depends on pre-gravid body mass index (BMI); underweight women are recommended an increase of 150, 200 and 300 kcal d during the first, second and third trimester, normal weight women an increase of 0, 350 and 500 kcal d and obese women an increase of 0, 450 and 350 kcal day. The recommendations for carbohydrate and protein intake are 175 g d and 0.88-1.1 g kgBM d, with no change to fat intake. The number of pre-gravid obese women is rising; therefore, we need to regulate weight in women of childbearing age and limit gestational weight gain to within the recommended ranges [overweight women 6.8-11.3 kg and obese women 5.0-9.1 kg]. This can be achieved using nutritional interventions, as dietary changes have been shown to help with gestational weight management. As pregnancy has been identified as a risk factor for the development of obesity, normal weight women should gain 11.5-16.0 kg during pregnancy. While some research has shown that dietary interventions help to regulate gestational weight gain and promote postpartum weight loss to some extent, future research is needed to provide safe and effective guidelines to maximise these effects, while benefitting maternal and foetal health.
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