diff --git a/mpwo_client/src/actions/activities.js b/mpwo_client/src/actions/activities.js
index 999b54ec..18ebc5ff 100644
--- a/mpwo_client/src/actions/activities.js
+++ b/mpwo_client/src/actions/activities.js
@@ -2,7 +2,7 @@ import mpwoGenericApi from '../mwpoApi'
 import mpwoApi from '../mwpoApi/activities'
 import { history } from '../index'
 import { formatChartData } from '../utils'
-import { setError } from './index'
+import { setError, setLoading } from './index'
 
 export const pushActivities = activities => ({
   type: 'PUSH_ACTIVITIES',
@@ -23,10 +23,17 @@ export const addActivity = form => dispatch => mpwoApi
   .addActivity(form)
   .then(ret => {
     if (ret.status === 'created') {
-      history.push(`/activities/${ret.data.activities[0].id}`)
+      if (ret.data.activities.length === 0) {
+          dispatch(setError('activities: no correct file'))
+      } else if (ret.data.activities.length === 1) {
+          history.push(`/activities/${ret.data.activities[0].id}`)
+      } else { // ret.data.activities.length > 1
+          history.push('/')
+      }
     } else {
       dispatch(setError(`activities: ${ret.message}`))
     }
+    dispatch(setLoading())
   })
   .catch(error => dispatch(setError(`activities: ${error}`)))
 
@@ -97,6 +104,7 @@ export const editActivity = form => dispatch => mpwoGenericApi
     } else {
       dispatch(setError(`activities: ${ret.message}`))
     }
+    dispatch(setLoading())
   })
   .catch(error => dispatch(setError(`activities: ${error}`)))
 
diff --git a/mpwo_client/src/actions/index.js b/mpwo_client/src/actions/index.js
index e8255a3b..7730976b 100644
--- a/mpwo_client/src/actions/index.js
+++ b/mpwo_client/src/actions/index.js
@@ -13,6 +13,10 @@ export const setError = message => ({
   message,
 })
 
+export const setLoading = () => ({
+  type: 'SET_LOADING',
+})
+
 export const getData = (target, id = null, data = null) => dispatch => {
   if (id !== null && isNaN(id)) {
     return dispatch(setError(target, `${target}: Incorrect id`))
diff --git a/mpwo_client/src/components/Activities/ActivityAddOrEdit.jsx b/mpwo_client/src/components/Activities/ActivityAddOrEdit.jsx
index 1fad5ca0..fb264a48 100644
--- a/mpwo_client/src/components/Activities/ActivityAddOrEdit.jsx
+++ b/mpwo_client/src/components/Activities/ActivityAddOrEdit.jsx
@@ -1,10 +1,11 @@
 import React from 'react'
 import { Helmet } from 'react-helmet'
+import { connect } from 'react-redux'
 
 import FormWithGpx from './ActivityForms/FormWithGpx'
 import FormWithoutGpx from './ActivityForms/FormWithoutGpx'
 
-export default class ActivityAddEdit extends React.Component {
+class ActivityAddEdit extends React.Component {
   constructor(props, context) {
     super(props, context)
     this.state = {
@@ -21,7 +22,7 @@ export default class ActivityAddEdit extends React.Component {
   }
 
   render() {
-    const { activity, message, sports } = this.props
+    const { activity, loading, message, sports } = this.props
     const { withGpx } = this.state
     return (
       <div>
@@ -59,6 +60,7 @@ export default class ActivityAddEdit extends React.Component {
                             <input
                               type="radio"
                               name="withGpx"
+                              disabled={loading}
                               checked={withGpx}
                               onChange={event => this.handleRadioChange(event)}
                             />
@@ -70,6 +72,7 @@ export default class ActivityAddEdit extends React.Component {
                             <input
                               type="radio"
                               name="withoutGpx"
+                              disabled={loading}
                               checked={!withGpx}
                               onChange={event => this.handleRadioChange(event)}
                             />
@@ -96,3 +99,8 @@ export default class ActivityAddEdit extends React.Component {
   }
 }
 
+export default connect(
+  state => ({
+    loading: state.loading
+  }),
+)(ActivityAddEdit)
diff --git a/mpwo_client/src/components/Activities/ActivityForms/FormWithGpx.jsx b/mpwo_client/src/components/Activities/ActivityForms/FormWithGpx.jsx
index 0c3d0466..aae64f2d 100644
--- a/mpwo_client/src/components/Activities/ActivityForms/FormWithGpx.jsx
+++ b/mpwo_client/src/components/Activities/ActivityForms/FormWithGpx.jsx
@@ -1,12 +1,15 @@
 import React from 'react'
 import { connect } from 'react-redux'
 
+import { setLoading } from '../../../actions/index'
 import { addActivity, editActivity } from '../../../actions/activities'
 import { history } from '../../../index'
 
 
 function FormWithGpx (props) {
-  const { activity, onAddActivity, onEditActivity, sports } = props
+  const {
+    activity, loading, onAddActivity, onEditActivity, sports
+  } = props
   const sportId = activity ? activity.sport_id : ''
   return (
     <form
@@ -20,6 +23,7 @@ function FormWithGpx (props) {
           <select
             className="form-control input-lg"
             defaultValue={sportId}
+            disabled={loading}
             name="sport"
             required
           >
@@ -39,6 +43,7 @@ function FormWithGpx (props) {
             <input
               name="title"
               defaultValue={activity ? activity.title : ''}
+              disabled={loading}
               className="form-control input-lg"
             />
           </label>
@@ -46,10 +51,12 @@ function FormWithGpx (props) {
       ) : (
         <div className="form-group">
           <label>
-            GPX file:
+            <strong>gpx</strong> file or <strong>zip</strong>{' '}
+            file containing <strong>gpx</strong> (no folder inside):
             <input
-              accept=".gpx"
+              accept=".gpx, .zip"
               className="form-control input-lg"
+              disabled={loading}
               name="gpxFile"
               required
               type="file"
@@ -57,30 +64,39 @@ function FormWithGpx (props) {
           </label>
         </div>
       )}
-      <input
-        type="submit"
-        className="btn btn-primary btn-lg btn-block"
-        onClick={
-          event => activity
-          ? onEditActivity(event, activity)
-          : onAddActivity(event)
-        }
-        value="Submit"
-      />
-      <input
-        type="submit"
-        className="btn btn-secondary btn-lg btn-block"
-        onClick={() => history.go(-1)}
-        value="Cancel"
-      />
+      {loading ? (
+        <div className="loader" />
+      ) : (
+        <div>
+          <input
+            type="submit"
+            className="btn btn-primary btn-lg btn-block"
+            onClick={
+              event => activity
+                ? onEditActivity(event, activity)
+                : onAddActivity(event)
+            }
+            value="Submit"
+          />
+          <input
+            type="submit"
+            className="btn btn-secondary btn-lg btn-block"
+            onClick={() => history.go(-1)}
+            value="Cancel"
+          />
+        </div>
+      )}
     </form>
   )
 }
 
 export default connect(
-  () => ({ }),
+  state => ({
+    loading: state.loading
+  }),
   dispatch => ({
     onAddActivity: e => {
+      dispatch(setLoading())
       const form = new FormData()
       form.append('file', e.target.form.gpxFile.files[0])
       form.append(
@@ -89,6 +105,7 @@ export default connect(
       dispatch(addActivity(form))
     },
     onEditActivity: (e, activity) => {
+      dispatch(setLoading())
       dispatch(editActivity({
         id: activity.id,
         sport_id: +e.target.form.sport.value,
diff --git a/mpwo_client/src/components/App.css b/mpwo_client/src/components/App.css
index 88780836..7015e898 100644
--- a/mpwo_client/src/components/App.css
+++ b/mpwo_client/src/components/App.css
@@ -173,3 +173,18 @@ input, textarea {
 .unlink {
   color: black;
 }
+
+.loader {
+  animation: spin 2s linear infinite;
+  border: 16px solid #f3f3f3;
+  border-top: 16px solid #3498db;
+  border-radius: 50%;
+  height: 120px;
+  margin-left: 41%;
+  width: 120px;
+}
+
+@keyframes spin {
+  0% { transform: rotate(0deg); }
+  100% { transform: rotate(360deg); }
+}
diff --git a/mpwo_client/src/reducers/index.js b/mpwo_client/src/reducers/index.js
index bc653d4e..7aa56998 100644
--- a/mpwo_client/src/reducers/index.js
+++ b/mpwo_client/src/reducers/index.js
@@ -93,6 +93,15 @@ const gpx = (state = initial.gpx, action) => {
   }
 }
 
+const loading = (state = initial.loading, action) => {
+  switch (action.type) {
+    case 'SET_LOADING':
+      return !state
+    default:
+      return state
+  }
+}
+
 const message = (state = initial.message, action) => {
   switch (action.type) {
     case 'AUTH_ERROR':
@@ -176,6 +185,7 @@ const reducers = combineReducers({
   formData,
   formProfile,
   gpx,
+  loading,
   message,
   messages,
   records,
diff --git a/mpwo_client/src/reducers/initial.js b/mpwo_client/src/reducers/initial.js
index a6fcf7b7..d8a5004c 100644
--- a/mpwo_client/src/reducers/initial.js
+++ b/mpwo_client/src/reducers/initial.js
@@ -44,6 +44,7 @@ export default {
   chartData: [],
   // check if storing gpx content is OK
   gpx: null,
+  loading: false,
   records: {
     ...emptyData,
   },