If you separate each cycle into a separat row, the rows will likely have data of different lengths, which then gets hard to work with because you'll need to store them in cell arrays. As a starting point, here's what I'd do:
t = readtable("h1l_130710_1_110.xlsx");
t.Min = islocalmin(t.Fz,"MinProminence",500); % this works pretty well.
% % I recommend using the "Find Local Extrema" live task to play around with peak-finding parameters interactively.
t.Cycle = cumsum(t.Min);
t.Min = [] % probably don't need this any more
% now you have Cycle as a grouping variable and you can use things like
% groupsummary or varfun to do calculations on each gait cycle.
%If you really want the data as rows...
t = varfun(@(x) {x'}, t, "GroupingVariables","Cycle")
