A settlement of Temiars, an aboriginal tribe residing in the north-eastern jungles of the Malay Peninsula, was selected for a study of their cardiorespiratory fitness. A step-test was used to elicit the Vo2max, V E max and HR max in a group of 19 boys aged 12 to 18 years and 6 men aged 19 - 40 years. The mean VO2max of the boys was found to be 45.9 +/- 6.9 ml-kg-1-min-1 compared with 45.6 +/- 5.4 ml-kg-1-min-1 for the men. The mean V E max, HR max and blood lactate levels were found to be 65.5 +/- 11.31/min and 69.2 +/- 23.71/min; 194 +/- 8 beats/min and 186 +/- 10 beats/min; and 79.8 +/- 13.4 mg% and 97.7 +/- 33.4 mg% respectively. These results are comparable to those obtained in urban populations as well as those found in other primitive communities. Telemetric monitoring of the routine daily physical activity of the men revealed that these jungle dwellers rarely tax their oxygen transport systems in their daily living and their cardiorespiratory functions were similar to communities who do not specifically train for physical fitness.
The purpose of the study was to investigate whether a combination of sago and soy protein ingested during moderate-intensity cycling exercise can improve subsequent high-intensity endurance capacity compared with a carbohydrate in the form of sago and with a placebo. The participants were 8 male recreational cyclists with age, weight, and VO2max of 21.5 +/- 1.1 yr, 63.3 +/- 2.4 kg, and 39.9 +/- 1.1 ml . kg(-1) . min(-1), respectively. The design of the study was a randomized, double-blind placebo-controlled crossover comprising 60 min of exercise on a cycle ergometer at 60% VO2max followed by a time-to-exhaustion ride at 90% VO2max. The sago feeding provided 60 g of carbohydrate, and the sago-soy combination provided 52.5 g of carbohydrate and 15 g of protein, both at 20-min intervals during exercise. Times to exhaustion for the placebo, sago, and sago-soy supplementations were 4.09 +/- 1.28, 5.49 +/- 1.20, and 7.53 +/- 2.02 min, respectively. Sago-soy supplementation increased endurance by 84% (44-140%; p < .001) and by 37% (15-63%; p < .05) relative to placebo and sago, respectively. The plasma insulin response was elevated above that with placebo during sago and sago-soy supplementations. The authors conclude that a combination of sago and soy protein can delay fatigue during high-intensity cycling.
Interacting effects of feeding and stress on corticoid responses in fish were investigated in common carp fed 3.0% or 0.5% body mass (BM) which received no implant, a sham or a cortisol implant (250 mg/kg BM) throughout a 168 hour post-implant period (168 h-PI). At 12h-PI, cortisol implants elevated plasma cortisol, glucose and lactate. Plasma osmolality and ions remained stable, but cortisol increased gill and kidney Na(+)/K(+) ATPase (NKA) and H(+) ATPase activities. Gill NKA activities were higher at 3%-BM, whereas kidney H(+) ATPase activity was greater at 0.5%-BM. Cortisol induced liver protein mobilization and repartitioned liver and muscle glycogen. At 3%-BM, this did not increase plasma ammonia, reflecting improved excretion efficiency concomitant with upregulation of Rhesus glycoprotein Rhcg-1 in gill. Responses in glucocorticoid receptors (GR1/GR2) and mineralocorticoid receptor (MR) to cortisol elevation were most prominent in kidney with increased expression of all receptors at 24 h-PI at 0.5%-BM, but only GR2 and MR at 0.5%-BM. In the liver, upregulation of all receptors occurred at 24 h-PI at 3%-BM, whilst only GR2 and MR were upregulated at 0.5%-BM. In the gill, there was a limited upregulation: GR2 and MR at 72 h-PI and GR1 at 168 h-PI at 3%-BM but only GR2 at 72 h-PI at 0.5%-BM. Thus cortisol elevation led to similar expression patterns of cortisol receptors in both feeding regimes, while feeding affected the type of receptor that was induced. Induction of corticoid receptors occurred simultaneously with increases in Rhcg-1 mRNA expression (gill) but well after NKA and H(+) ATPase activities increased (gill/kidney).