J. Greene, M. Gard, C. Cibula, M. Bonnema, V. Axtell, and D.B. Thorp

Gonzaga University, Spokane, WA

PURPOSE: To investigate the effect of Adderall on exercise performance, including the cognitive effects of Adderall in relation to exercise performance, in individuals with attention deficit hyperactivity disorder (ADHD). Sex differences in these effects were also examined. METHODS: Participants with diagnosed ADHD and prescribed Adderall (n= 9, 5 females, 4 males, age = 21.5 ± 1.7 yr.) completed 3 testing sessions: familiarization, one with Adderall, and one without Adderall; the two experimental trials were counterbalanced. Baseline physiological measurements (blood pressure (BP), tympanic temperature (TyT), and blood lactate (BL), were collected before a two-minute warm-up. A Stroop Test and ADHD symptoms questionnaire were administered before the test to assess the percent change (%Δ) in cognitive function and ADHD severity between the trials. Participants completed a ramp test to volitional exhaustion on a cycle ergometer (starting at 50 W and increasing by 1 Watt every 4 seconds). Time to exhaustion (TTE) and maximal power output (POmax) were recorded. BP and TyT were measured every 3 minutes and heart rate (HR) was measured continuously. Post-test BP, TyT, and BL were measured. A two-way ANOVA (α = .05) was used to assess the effects of Adderall and sex on TTE and POmax. A mixed model ANOVA was used to examine the effect of sex, time, and Adderall on BP, TyT, BL, and HR throughout the test. Kendall tau correlation was used to examine the relationship between cognitive function and symptom severity with TTE. RESULTS: Adderall increased TTE (Adderall: 692.8 ± 185.12 s; w/o Adderall: 663.33 ± 166.19 s, p = .018), POmax (Adderall: 222.9 ± 47W; w/o Adderall: 215.3 ± 42W, p=.017), HRmax (Adderall: 186 ± 6.2 bpm; w/o Adderall: 179 ± 10.3 bpm, (p = .001), and BL (Adderall [baseline]: 3.28 ± 2.32 mM, [post-test]: 12.23 ± 2.56 mM; w/o Adderall [baseline]: 1.92 ± 0.95 mM, [post-test]: 10.98 ± 2.46 mM, p = .044). No relationship was found between cognitive function (i.e., Stroop Test) or ADHD symptoms with TTE (% ΔStroop vs.% ΔTTE r(7) = .444, p = .095; % ΔADHD score vs. % ΔTTE r(7) = .056, p = .835). CONCLUSION: Adderall enhances exercise performance in an exhaustive ramp protocol test, as seen by an increased TTE, POmax, HRmax, and tolerance to BL. However, sex does not impact the extent to which Adderall enhances exercise performance.

*This study was funded by Gonzaga University’s Human Physiology Department.

This document is currently not available here.