figure

f = 0:1000/4096:1000-1000/4096;

glu = abs(fft(EMGdat.chan11,4096));
sol = abs(fft(EMGdat.chan1,4096));
vas = abs(fft(EMGdat.chan5,4096));

plot(f,glu);
hold on;
plot(f,sol,'r');
plot(f,vas,'g');

legend('GLU','SOL','VAS');
grid on;