No abstract

Exercise in young adults (18-25 y) suppresses appetite in a dose-response relationship with exercise intensity. While several mechanisms have been proposed to explain this response, lactate is the most well established. To date, no study has investigated this specifically in middle-aged adults where the appetite response to a meal is different. PURPOSE: To explore the effects of submaximal, near maximal, and supramaximal intensity exercise on appetite regulation in middle-aged adults. METHODS: Nine participants (age: 45±10 y) completed 4 experimental sessions: 1) no-exercise control (CTRL); 2) moderate-intensity continuous training (MICT; 30 min, 65% V̇O2max); 3) high-intensity interval training (HIIT; 10 x 1 min efforts, 90% heart rate maximum, 1 min recovery); and 4) sprint interval training (SIT; 8 x 15 s "all-out" efforts, 2 min recovery). Acylated ghrelin, active glucagon-like peptide-1 (GLP-1), active peptide tyrosine tyrosine (PYY), lactate, and subjective appetite perceptions were measured pre-exercise, 0-, 30-, and 90-min post-exercise. Energy intake was recorded the day before and of each session. RESULTS: Acylated ghrelin was suppressed (P<0.001, =0.474) by HIIT (0-min, and 30-min post-exercise; P<0.091, d>1.84) and SIT (0-min, 30-min, and 90-min post-exercise; P<0.037, d>1.72) compared to CTRL, and SIT suppressed concentrations compared to MICT (0-min, and 30-min post-exercise; P<0.91, d>1.19). There were no effects of exercise on active PYY, active GLP-1, appetite perceptions, or free-living energy intake (P>0.126, <0.200). CONCLUSION: Intense interval exercise that generates lactate accumulation suppresses acylated ghrelin with little effect on anorexigenic hormones, overall appetite, or free-living energy intake.

Handedness is a significant behavioral asymmetry; however, there is debate surrounding the age at which hand preference develops, and little research has been conducted on handedness in older adults. The current study examined performance on the long pegboard, to identify similarities and differences in young children (ages 4–7 years), older children (ages 8–12 years), young adults (ages 18–25 years), and older adults (ages 70+ years). Average time per hole, number of hand switches, and errors were assessed with left‐ and right‐hand starts. A left‐right ratio was computed from the long pegboard, along with laterality quotients from the Waterloo Handedness Questionnaire (WHQ). Results revealed faster performance when participants started the task on the right side of the long pegboard with the right‐hand, coupled with a later switch to the left‐hand. There was a greater number of errors with left‐hand starts, and an earlier switch to the right‐hand. Age was a significant predictor of the average time per hole and number of errors. Long pegboard ratio and WHQ laterality quotient were only correlated for adults. Together, findings offer insight regarding age‐related effects in handedness and support the long pegboard as a useful measure of handedness.